A phenomenon is termed parthenogenesis when

[CBSE PMT 1990]

(a) Artificial fertilization occurs

(b) Egg is fertilized by a sperm

(d) Sperm dies before fertilization

Which of the drug inhibits metamorphosis in frog.

[AIIMS 1988]

(a) Paracetamol (b) Penicillin

Jelly layer of frog is

(a) Primary membrane (b) Secondary membrane

The structure which remains unchanged during metamorphosis of frog’s tadpole is [AIIMS 1998]

(a) Lung (b) Heart

Beginning of archenteron formation in frog’s development represents the stage [BHU 2000]

(a) Morula (b) Early blastula

In the development of a frog, the gastrulation process involves [CPMT 2001]

(a) Epiboly (b) Emboly

In the adult phase of frog which of the character become degenerate [AFMC 2003]

(a) Tail (b) Legs

Blastula of frog has [BHU 2004]

(a) Blastopore (b) Blastocoel

Third cleavage of frog’s development is [MH CET 2003]

(a) Equatorial (b) Vertical

Correct sequence in embryonic development of frog is

[BCECE 2005]

(a) Zygotes ®Cleavage®Blastula®Gastrula

(b) Zygotes ®Cleavage®Gastrula®Blastula

(d) Zygotes ® Blastula®Cleavage®Gastrula

Neoteny refers to [Kerala CET 2005]

(a) Development of gonads

(b) Pre-adult animal

(d) Retention of Larval or embryonic trait in adult body

(e) Precocious development

Grey crescent is the area [CBSE PMT 2005]

(a) At the point of entry of sperm into ovum

(b) Just opposite to the site of entry of sperm into ovum

(d) At the vegetal pole

Blastula of frog is [Manipal 2005]

(a) Amphiblastula (b) Coeloblastula

Fertilization is external in [MP PMT 1998]

(a) Lizards (b) Rats

The third cleavage in frog’s development is [CPMT 1984]

(a) Holoblastic and equatorial

(b) Holoblastic and unequatorial

(d) Meroblastic and vertical

Grey crescent is present in [KCET 2000]

(a) Fertilized egg of frog (b) Brain of rabbit

In most of the mammals the testes are situated outside the abdominal cavity because [CPMT 1987; Kerala PMT 2005]

(a) Sperms produced in scrotal sac are more in number

(b) Sperms produced in abdominal cavity are provided with less motility

(d) Sperms produced in scrotal sac are bigger

The correct order of the reproductive tract of a male human being is [DPMT 1992]

(a) Rete testis, epididymis, vasa efferentia, urethra

(b) Rete testis, vasa efferentia, epididymis, urethra

(d) Urethra, rete testis, epididymis, vasa efferentia

Failure of descending testis into scrotum is known as

[CPMT 1980; AIIMS 1980, 83; DPMT 1993]

(a) Impotency (b) Cryptorchidism

Which of the following cells are present in mammalian testes and help to nourish sperms

[AFMC 1997; KCET 2001; CPMT 2003; Kerala CET 2003]

(a) Leydig cells (b) Oxyntic cells

Cumulus covers [AIIMS 1999]

(a) Ovary (b) Ovum

In rabbit, ex-abdominal reproductive organs are

[RPMT 2001]

(a) Testes, Penis, Epididymis

(b) Testes, Vas deferens, Testes sac

(d) Testes sac, Seminal Vesicle, Epididymis

Clitoris in mammals is

[DPMT 1985; CPMT 1980, 84, 93; BHU 1985;

MP PMT 1993; RPMT 2001]

(a) Homologous to penis

(b) Analogous to penis

(d) Non-functional penis in male

Vulva is enclosed by

(a) Vaginal orifice

(b) Clitoris

(d) Labia majora and minora both

If ovaries of a pregnant mammal are removed

(a) The embryonic development will stop

(b) Embryo will regenerate

(d) Ovaries will regenerate

Ostium is provided with a number of finger like processes fimbriae

(a) For receiving ovum

(b) To increase the catching area

(d) To secrete hormones

Ovulation occurs

(a) Alternately from two ovaries

(b) Simultaneously from both the ovaries

(d) According to the season from two ovaries

Precocious puberty is

(a) Delayed puberty

(b) Puberty attained before the normal age

(d) None of these

Implantation or uterine attachment of the blastocyst presumably occurs between

(a) and days after ovulation

(b) and days after ovulation

(d) and days after ovulation

Atretic follicles are found in the [MP PMT 1996, 2002]

(a) Liver (b) Testis

Secretion of progesterone by corpus luteum is initiated by

[CBSE PMT 1999]

(a) LH (b) MSH

Onset of menstruation is due to [DPMT 2003]

(a) Fall in level of progesterone

(b) Increase in level of progesterone

(d) None of these

The phase of menstrual cycle in humans that last for 7-8 days is [AIIMS 2003]

(a) Follicular phase (b) Ovulatory phase

The region where sperm enters the egg is called

[NCERT 1972; CPMT 1974; RPMT 2001, 02]

(a) Equator (b) Receptor cone

Fraternal twins in man are produced when

[CMC Vellore 1993]

(a) Two sperms fertilize an ovum and the first two blastomeres separate from each other

(b) One sperm fertilizes an ovum and first two blastomeres separate from each other

(d) Two ova are fertilized simultaneously

The chemical substance found in the surface layer of cytoplasm of spermatozoa is [MP PMT 1994]

(a) Fertilizin (b) Agglutinin

Fertilization restores [MP PMT 1994]

(a) Haploidy from diploidy (b) Diploidy from polyploidy

Polyspermy refers to

(a) Formation of many sperms by a male

(b) Changes in sperm nucleus

(d) Penetration of many sperms into an ovum simultaneously

At what stage the primitive streak in the chick embryo is formed

(a) 12 hours incubation (b) 18 hours incubation

Which of the following statement is not correct

(a) Fertilizin of one species of animal will react with antifertilizin of another species

(b) Fertilizin of one species of animal will react with the antifertilizin of the same species

(d) Molecular weight of fertilizin is about 3,00,000 and antifertilizin 10,000

External stimulus which induces cleavage in an unfertilized ovum is called

(a) Fertilization (b) Chemotaxis

Which one of the following is the effect of higheron the sperms

(a) Sperms become sluggish with longer life

(b) Sperms become less active with short life

(d) No effect

The first meiotic division in the oogonium is completed when the egg is within the

(a) Uterus

(b) Follicle

(d) Ovary, before it is surrounded by follicles

The point of sperm entry during fertilization forms

[MP PMT 1998]

(a) Centre of rotation of embryo

(b) Axis of cleavage

(d) Dorsal lip of blastopore

Which statement is correct for fertilization [RPMT 2001]

(a) Restore Euploidy

(b) Brings male & female gametes together

(d) All of these

Which distinguishes a morula from a blastula

[MP PMT 1992]

(a) Presence of more yolk (b) Absence of yolk

Holoblastic cleavage may occur in eggs which are

[AIIMS 1987; MP PMT 1994]

(a) Oligolecithal only

(b) Mesolecithal only

(d) Oligolecithal and mesolecithal both

Embryologists can presume the future organs of the embryo in [CPMT 1980; CBSE PMT 1993]

(a) Blastula (b) Early gastrula

The fluid filled in the blastocoel cavity of blastula is

[CPMT 1988; AIIMS 1993]

(a) Acidic (b) Albuminous

In a mesolecithal egg, one would expect [DPMT 1976]

(a) Meroblastic cleavage

(b) Unequal holoblastic cleavage

(d) None of these

During the fourth and sixth cleavage of the zygote

[AIIMS 1993]

(a) Mesomeres give rise to endoderm

(b) Micromeres give rise to ectoderm

(d) Macromeres give rise to ectoderm

What is true about cells during cleavage [CBSE PMT 1991]

(a) They move from animal pole to vegetal pole

(b) They do not grow in size

(d) Their divisions resemble ordinary mitosis

The solid mass of cells formed at the end of cleavage of mammalian egg is [MP PMT 1994]

(a) Blastula (b) Morula

The type of blastula formed in birds is

[MP PMT 1994; RPMT 1999]

(a) Teloblastula (b) Holoblastula

In mature oocytes cortical granules are formed on which side of plasmalemma

(a) Outer (b) Inner

During cleavage DNA synthesis

(a) Increases (b) Decreases

Of the following animals which produces the smallest egg

(a) Humming bird (b) Salmon

Spiral cleavage is found in

(a) Synapta

(b) Amphibia

(d) None of the above

Which of the following is not evident that the pattern of cleavage is determined by factors in the egg cytoplasm rather than by genes of zygote

(a) Cleavage is prevented by injection of a protein synthesis inhibitor

(b) Cleavage is not affected by injection of inhibitors of RNA synthesis into the zygote

(d) The direction of the first division of cleavage in the snail Cepaea is determined by the mothers genotype

Which of the following structure is found in blastula

[CPMT 1995]

(a) Segmentation cavity (b) Notochord

Which of the following cannot pass through the placenta into the foetus

(a) Bacteria of syphilis (b) Thalidomide

The blastula of prototherians is called

(a) Blastocyst (b) Stereoblastula

How many eggs will be formed from 100 primary oocytes

[MP PMT 1997, 2000]

(a) 300 (b) 400

Blastocyst is a modified blastula of [MP PMT 1997]

(a) Placental mammals (b) Frog

Cleavage is a unique form of mitotic cell division in which

[CPMT 1999; JIPMER 2001]

(a) The nucleus does not participate

(b) There is no growth of cells

(d) The plasma membranes of daughter cells do not separate

Meroblastic cleavage refers to one of the following types of division of eggs [KCET 1998]

(a) Total (b) Partial

When centrolecithal egg of the insects divides regularly then what will happen [RPMT 2001]

(a) Cells surround the yolk

(b) Yolk surround the cells

(d) Yolk lie above the group of cells

How many divisions occur when a isolated cell is divided into 128 cells [AFMC 2002]

(a) 64 (b) 127

The attachment of the mammalian blastocyst to the uterine wall is [CBSE PMT 1993]

(a) Incest (b) Implantation

From the egg in gastrula stage if you remove all cells which form endoderm, the new organism will lack of [DPMT 1982]

(a) Eyes

(b) Heart

(d) Some of the visceral organs

The best definition of the process of gastrulation is that, it is a process where the [AIIMS 1983; DPMT 1985]

(a) Single layered blastula becomes two layered

(b) Archenteron is formed

(d) Zygote gets converted to a larva

Ontogenetically liver and pancreas are or During embryonic development pancreas and liver develop from which germinal layer [CPMT 1973, 83, 84; MP PMT 1996]

(a) Ectoderm (b) Mesoderm

Archenteron is formed during [CPMT 1984; MP PMT 2002]

(a) Early blastula (b) Morula stage

Which of these sets of cells divide slowly [JIPMER 1993]

(a) Micromeres (b) Megameres

True coelom develops as a split in

[CBSE PMT 1990; RPMT 1995; J & K CET 2002]

(a) Mesoderm

(b) Endoderm

(d) Between ectoderm and endoderm

Middle gastrula is characterised by [CPMT 1993]

(a) Formation of yolk plug

(b) Archenteron just beings to form

(d) Yolk plug shifts towards blastopore

The literal meaning of “gastrulation” is [MP PMT 1994]

(a) Formation of primary germ layers

(b) Formation of a gut

(d) Commencement of organogenesis

Which of the following structure originates from ectoderm

[RPMT 1995]

(a) Stomodaeum (b) Proctodaeum

Blastopore is found in [MP PMT 1998]

(a) Blastula and is opening of archenteron

(b) Blastula and is opening of blastocoel

(d) Gastrula and is opening of blastocoel

Which of the following is not correct for gastrulation

[RPMT 2002]

(a) Archenteron is formed

(b) All germinal layers are formed

(d) Some blastomeres & blastocoel degenerate

During the course of development, cells in various regions of embryo become variable in morphology and eventually perform diverse functions. This process is known as

[CBSE PMT 1989; CMC Vellore 1993]

(a) Rearrangement (b) Differentiation

If the ectoderm from neural tissue area is removed from the embryo and transplanted in place of presumptive belly ectoderm embryo will develop [AIIMS 1983; AFMC 1985]

(a) Without a neural tube

(b) With a neural tube

(d) With two neural tube

Relative sizes of an egg cell, morula, blastula and gastrula are [CPMT 1993]

(a) Egg cell is largest and morula is smallest

(b) Egg cell is smallest and gastrula is largest

(d) All are of equal size

In the development of man which structures are formed from splanchnopleure.

(a) Muscles and connective tissue of digestive tube

(b) Vertebral column and spinal cord

(d) Urinogenital organs

When a small piece of dorsal lip of blastopore of frog’s early gastrula is transplanted into another gastrula of similar age at ventral lip, the result is [MP PMT 1990]

(a) Death of the graft tissue

(b) The host gastrula undergoes abnormal development

(d) The graft tissue induces development of another notochord in the host

During the development of embryo which of the following occur first [AFMC 1995]

(a) Differentiation of tissue

(b) Differentiation of cells

(d) Differentiation of organ system

In embryonic stage RBC develops in [MP PMT 1996]

(a) Liver and kidney (b) Liver and spleen

In both chordates and non-chordates intestine develops from [RPMT 2000]

(a) Pharyngeal pouch (b) Ectoderm

During embryonic development, the establishment of polarity along anterior/ posterior, dorsal/ventral or medial/lateral axis is called [CBSE PMT 2003]

(a) Pattern formation (b) Organizer phenomena

The amnion and chorion consist of which type of composition

(a) Somatopleure (b) Splenchnopleure

The extra–embryonic membranes of the mammalian embryo are derived from [CBSE PMT 1994]

(a) Formative cells (b) Follicle cells

Chorion is found [MP PMT 1994]

(a) Inside the amnion (b) Outside the amnion

Extra embryonic membrane amnion is not found in amphibians because [RPMT 2001]

(a) They lay eggs in water (b) Egg hatches in tadpole

The permeability of the human placenta to macro-molecules is evidenced by the presence of following in foetal blood

[AIIMS 1985]

(a) Globulin (b) Albumin

The placental barrier between the maternal and foetal blood is minimum in [AIIMS 1992]

(a) Goat (b) Pig

Umbilical cord in mammals, contains [BHU 1988]

(a) Placenta (b) Umbilicus

Mammalian placenta has minute finger like projections called

(a) Chorionic villi (b) Chorionic network

Read the assertion and reason carefully to mark the correct option out of the options given below :

(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion

(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion

(c) If the assertion is true but the reason is false

(d) If both the assertion and reason are false

(e) If the assertion is false but reason is true

Assertion : Prostate and seminal vesicles are said to be primary sex organs.

Reason : Prostate and seminal vesicles participate and help in reproduction

Assertion : Embryonic development proves interrelationship and common ancestory of metazoans.

Reason : It involves similar sequence of five dynamic processes during development.

Assertion : There is generally monospermy in most of animals.

Reason : Vitelline membrane of ovum checks polyspermy.

Assertion : Penetration of sperm into ovum is a chemical process.

Reason : Acrosome of sperm secretes a lytic enzyme hyaluronidase which dissolves vitelline membrane of ovum.

Assertion : Cleavage is also called fractionating process.

Reason : In cleavage, number of blastomeres increases but size of blastomears decreases.

Assertion : Nuclear-cytoplasmic ratio decreases in cleavage.

Reason : During cleavage, cytoplasmic synthesis is faster than DNA synthesis.

Assertion : Implantation is the process of attachment of blastocyst on uterine endometrium.

Reason : Implantation is controlled by trophoblast and occurs by decidual cell reaction.

Assertion : Gastrular movements are morphogenetic.

Reason : During gastrulation, cells move in masses and towards definite direction.

Assertion : Asexual reproduction is also called blastogenesis.

Reason : In asexual reproduction, there is no formation and fusion of gametes.

Assertion : Individuals produced by asexual reproduction are genetically simillar to parents.

Reason : Asexual reproduction involves only mitotic divisions.

Assertion : Amoeba shows multiple fission during unfavourable conditions.

Reason : Chances of survival are less during unfavourable conditions.

Assertion : Sexual reproduction is advantageous than asexual reproduction.

Reason : It is rapid mode of reproduction while asexual reproduction is slow mode of reproduction.

Assertion : In honey bee, life history shows natural and complete parthenogenesis.

Reason : In honey bee, both drones and workers are parthenogenetically developed.

Assertion : In human male, testes are extra-abdominal and lie in scrotal sacs.

Reason : Scrotum acts as thermoregulator and keeps testicular temperature lower by 2°C normal spermatogenesis.

Assertion : Urethra in human male acts as urinogenital canal.

Reason : Urethra carries only urine while sperms are carried by vasa deferentia only.

Assertion : Penis of male is homologous to clitoris of human female.

Reason : Both are highly sensitive and both supported by corpora cavernosa.

Assertion : At puberty, human male develops secondary sexual characters.

Reason : At puberty, there is decreased secretion of testosterone in male.

Assertion : Fallopian funnel of oviduct is with finger-like fimbriae.

Reason : Graafian follicle of ovary is with secondary oocyte hanging in cavity called antrum.

Assertion : Corpus luteum degenerates if the ovum remains unfertilized.

Reason : Corpus luteum secretes progesterone which maintains the pregnancy.

Assertion : Size of breasts increases at puberty in human female.

Reason : Prolactin secretion starts at puberty.

Assertion : Vagina acts as copulation canal and fertilization canal.

Reason : Both insemination and fusion of gametes occur in vagina of female.

Assertion : Claspers of cartilage fishes are analogous to penis of human male.

Reason : Both act as copulatory organs and transfer the sperms into female.

Assertion : In human male, there are perianal glands near the anus.

Reason : Perianal glands secretes sex-attractant pheromone which initiates sexual desire in human female.

Assertion : Primary spermatocytes of testes are haploid.

Reason : Primary spermatocytes are formed by meiosis-I in the spermatogonia.

Assertion : Spermiation is the transformation of spermatid into sperm.

Reason : During spermiation, sperms get nutrition from sertioli cells.

Assertion : During fertilization only head of spermatozoa enters egg.

Reason : If several spermatozoa hit the egg at same time, all can enter the egg. [AIIMS 1997]

Assertion : n morula stage, cells divide without increase in size.

Reason : Zona pellucida remain undivided till cleavage is complete. [AIIMS 1997]

Assertion : Holoblastic cleavage with almost equal sized blastomeres is a characteristic of placental animals.

Reason : Eggs of most mammals, including humans, are of centrolecithal type [AIIMS 2003]

Assertion : The development in cockroach is heterometabolous metamorphosis.

Reason : Young ones resemble the adults in all characters. [AIIMS 1995]

Reproduction and its type

1	d	2	d	3	a	4	d	5	b
6	d	7	d	8	b	9	b	10	a
11	b	12	c	13	c	14	d	15	b
16	d	17	b	18	d	19	b	20	a
21	d	22	b	23	c	24	b	25	c
26	b

Male reproductive system

1	b	2	b	3	a	4	b	5	c
6	d	7	d	8	a	9	a	10	c
11	a	12	b	13	a	14	c	15	b
16	d	17	c	18	d	19	b	20	b
21	c	22	d	23	c	24	d	25	b
26	d	27	c	28	a	29	c	30	d
31	b	32	d	33	b	34	a	35	c
36	b	37	c	38	d	39	a	40	d
41	b	42	c	43	d	44	c	45	b
46	d	47	a	48	c	49	b	50	a
51	b

Female reproductive system

1	a	2	a	3	a	4	b	5	a
6	b	7	b	8	d	9	a	10	b
11	a	12	b	13	d	14	b	15	b
16	b	17	b	18	a	19	d	20	c
21	d	22	c	23	d	24	c	25	d
26	b	27	a	28	b	29	b	30	a
31	b	32	b	33	b	34	c	35	c
36	c	37	b	38	a	39	c	40	b
41	d	42	c	43	b	44	b	45	a
46	c	47	d	48	c	49	a	50	a
51	d	52	a	53	c	54	a	55	a
56	c	57	d	58	b	59	a	60	c
61	c	62	b	63	d	64	c	65	b
66	b	67	c	68	e	69	c	70	a
71	c	72	b	73	b	74	c	75	a
76	a	77	c	78	a

Gametogenesis

1	a	2	b	3	a	4	c	5	d
6	b	7	a	8	a	9	b	10	b
11	d	12	d	13	b	14	c	15	c
16	c	17	c	18	a	19	d	20	a
21	c	22	b	23	b

Phase of embryonic development

1	b	2	c	3	a	4	a	5	c
6	c	7	c	8	c	9	c	10	d
11	a	12	b	13	c	14	d	15	a
16	a

Fertilization

1	a	2	c	3	a	4	d	5	c
6	d	7	a	8	d	9	b	10	c
11	d	12	a	13	c	14	a	15	d
16	b	17	a	18	c	19	d	20	b
21	b	22	d	23	c	24	b	25	d
26	d	27	d	28	a	29	a	30	b
31	a	32	d	33	a	34	d	35	b
36	c	37	c	38	c	39	d	40	c
41	c	42	a	43	b	44	a	45	a
46	b	47	a

Cleavage

1	d	2	d	3	c	4	d	5	a
6	c	7	b	8	a	9	a	10	c
11	b	12	b	13	d	14	a	15	c
16	a	17	a	18	b	19	b	20	b
21	b	22	a	23	b	24	a	25	b
26	c	27	c	28	d	29	a	30	b
31	c	32	c	33	a	34	c	35	c
36	c	37	a	38	c	39	a	40	c
41	b	42	d	43	d	44	c	45	b
46	c	47	a	48	c	49	a	50	a
51	a	52	b	53	c	54	d	55	c
56	c	57	c	58	b	59	d	60	b
61	a	62	a	63	d	64	c	65	c
66	a	67	b	68	d	69	c	70	a
71	d	72	a	73	a	74	d	75	c
76	b	77	b	78	c	79	c

Implantation and Gastrulation

1	b	2	d	3	d	4	a	5	d
6	d	7	d	8	a	9	c	10	a
11	a	12	a	13	d	14	d	15	c
16	a	17	d	18	c	19	a	20	c
21	a	22	c	23	a	24	c	25	d
26	a	27	c	28	d	29	a	30	c
31	b	32	c	33	a	34	d	35	c

Neurulation and Organogenesis

1	a	2	c	3	a	4	b	5	c
6	c	7	d	8	c	9	c	10	c
11	a	12	a	13	a	14	a	15	b
16	b	17	a	18	b	19	a	20	c
21	b	22	c	23	b	24	c	25	a
26	d	27	a	28	a	29	a	30	c

Extra embryonic membrane

1	a	2	b	3	b	4	a	5	d
6	c	7	b	8	b	9	c	10	b
11	b	12	c	13	d	14	c	15	a
16	a	17	b	18	b	19	c	20	a
21	c	22	d	23	c	24	b	25	c
26	c	27	b

Placenta

1	c	2	b	3	c	4	d	5	d
6	b	7	d	8	c	9	c	10	a
11	b	12	c	13	d	14	b	15	c
16	b	17	b	18	a	19	d	20	c
21	a	22	a	23	d	24	d	25	a

Gestation period and parturipion

1	d	2	d	3	b	4	a	5	a
6	d	7	c	8	d

Development of frog

1	d	2	b	3	b	4	c	5	c
6	c	7	d	8	b	9	c	10	d
11	a	12	b	13	c	14	a	15	d
16	b	17	b	18	c	19	b	20	a

Critical Thinking Questions

1	c	2	b	3	b	4	d	5	b
6	a	7	a	8	d	9	a	10	c
11	a	12	b	13	c	14	d	15	a
16	a	17	b	18	b	19	d	20	c
21	d	22	d	23	b	24	a	25	a
26	a	27	b	28	b	29	d	30	d
31	d	32	a	33	b	34	b	35	b
36	b	37	b	38	d	39	b	40	a
41	c	42	c	43	a	44	a	45	d
46	d	47	d	48	a	49	b	50	b
51	a	52	c	53	b	54	d	55	c
56	c	57	c	58	b	59	a	60	a
61	b	62	d	63	c	64	d	65	b
66	c	67	d	68	a	69	d	70	b
71	b	72	c	73	b	74	a	75	d
76	b	77	a	78	c	79	d	80	c
81	a

Assertion and Reason

1	e	2	a	3	b	4	a	5	a
6	d	7	b	8	a	9	b	10	a
11	a	12	c	13	c	14	a	15	c
16	a	17	c	18	b	19	b	20	b
21	d	22	a	23	d	24	d	25	d
26	c	27	b	28	c	29	c

Reproduction and its type

(d) The apomixis is the formation of new individuals through asexual reproduction without involving the formation and fusion of gametes.
(a) Asexual reproduction is a method of reproduction which produces genetically identical clones.
(b) In sexual reproduction offspring’s are not genetically identical to the parents. They show variations as they receive characters from two different parents.
(d) The animals that have a recurrence of estrous during breeding season are called polyestrous e.g., mouse, cow sheep pig, horse etc.
(b) Most common forms of asexual reproduction in animals are fission and budding.
(b) Asexual reproduction occurs in a single individual with out production of gametes (in lower animals).
(b) Both sexual and asexual type of reproduction are found in Hydra.
(b) Binary fission may be longitudinal or transverse. During multiple fission, the parental body divides into many daughter organisms.
(b) Arrhenotoky is a type of parthenogenesis, in which the unfertilized eggs develop into males with haploid cells.
(a) Parthenogenesis can be classified into arrhenotoky and thelytoky.
(d) Binary fission occurs in Amoeba, paramecium, and planaria.
(b) Eutherian mammals are viviparous placental mammals without marsupium. Eutherians constitute the vast majority of living mammals arranged in 16 orders.
(c) Earthworms are bisexual but self fertilization does not occur because their testes ripes first. They are protandrous.
(b) Incomplete or cyclic parthenogenesis is found in those animals in which both sexual reproduction and parthenogenesis occur.
(b) Parthenogenesis is the development of an individual from an unfertilized egg. In honey bees drones develop parthenogenetically.

Male reproductive system

(b) In mammals the testis are located in the extra abdominal scrotal sac. But non descent of testes in scrotum is called cryptorchidism. Person becomes sterile.
(b) These are present in male mammals also known as bulbourethral glands. Situated beneath bladder and behind the urethra.
(b) Cowper’s gland open into urethra before entering into penis. Their secretion acts as a lubricants for the glans penis. It also neutralizes any urine in urethra.
(c) Each testis of man contains about 750 convoluted seminiferous tubules which give rise to spermatozoa.
(d) Each seminiferous tubules is lined by a germinal epithelium formed of two types of cell germ or spermetogenic cells and sertoli or nurse cells. Sertoli cells are a few pyramidal shaped cells which provide nutrition to developing sperms.
(d) This passes through the inguinal canal.
(a) Gubernaculum is the ligamentous connective (elastic) cord which connects testes to scrotal sac posteriorly. This cord represents the original mesorchium.
(a) Sertoli cells are located in seminiferous tubules which nourish spermatozoa.
(a) Cells of leydig or interstitial cells are stimulated to secrete male hormone testosterone by the interstitial cell stimulating hormone (ICSH) from anterior lobe of pituitary gland.
(b) Function of vasa deferentia are conduction of sperms by peristalsis of its highly muscular coat. It disconnected in man so semen will be without sperms.
(a) Each testes is externally covered by a white fibrous capsule the tunica albuginea which is produced inside the testis as fibrous septa.
(c) Through this testes descend into scrotal sacs.
(b) Since the secretion of Cowper’s gland lubricates the passage of sperms in urethra and also neutralizes the acidity in urethra due to previous micturition and makes the medium alkaline to keep the sperms alive, so its removal may affect sperms.
(d) Each testis is held in its position within its scrotal sac and is supported from posterior scrotal wall by means of a small cord of fibro muscular mesodermal tissue called Gubernaculum.
(d) Also known as antisterility vitamin.
(b) Cowper’s gland are present in male Rabbit these are yellow in colour their secretion is slightly alkaline and is produced during sexual stimulation.
(b) Testes are located in the extra-abdominal scrotal sacs and ovary remains attached to the abdominal wall by a ligament (mesovarium). Both are ventral to kidney.
(c) Between seminiferous tubules there are groups of polyhedral endocrine cells called interstitial or leydig’s cells. These secrete a steroid male sex hormone testosterone.
(c) Action of clotting enzyme (of prostate) over fibrinogen (of seminal vesicles) changes the semen into a coagulum in vagina.
(d) Semen is a milky viscous and alkaline fluid. The quantity is 2.5 to 4.0 ml at one time having some 400 million sperms. The fluid part is secreted by epididymis and seminal vesicles, prostate gland and cowper’s glands.
(b) Epididymis are long (4-6m) highly coiled narrow (0.4mm) tubules which lie compacted along the testes.
(c) Each epididymis is differentiated into upper caput epididymis, middle corpus epididymis and lower cauda epididymis.
(c) Tip of penis covered with retractile fold of skin called prepuce or fore skin.
(b) The scrotal sacs of a male mammals are homologous to labia majora of female. The clitoris which is homologous to penis.
(a) It is homologous to Cowper’s gland and has lubricating action by neutralising the acidity.
(c) In most of the mammals, testes are extra-abdominal as spermatogenesis requires a lower temperature for its normal completion.
(b) The germinal epithelium lining of the seminiferous tubules is made of two kinds of cell. A few larger cell columnar supporting cells are called sertoli cells or sustentacular cells on nurse cells.
(c) The germinal epithelium of testes requires a low temperature for their normal functioning.
(d) All the seminiferous tubules in each testis open into a network called rete testis leading to fine ductules called vasa efferentia.
(a) Each testicular lobules of testis contains two to three seminiferous tubules. Wall of each seminiferous tubules is formed of a single layered germinal epithelium.
(d) Cells of leydig are found in interstitial connective tissue of testes they secrete male hormone testosterone.
(b) At the medial side of frog’s kidney, Bidder’s canal is present into which the vasa efferentia open.
(c) Sertoli cells are located in seminiferous tubules in testes of rabbit which nourish spermatozoa.
(c) Leydig’s cells are endocrine in nature and secrete male sex hormones-androgens.
(b) The reproductive system of a male cockroach has a sac-like, accessory phallic gland located ventrally beneath the utricular gland.
(a) Testes are located in scrotum provides a low temperature (of 2°C) for maintenance of spermatogenetic tissue and formation of sperms.
(c) In males ICSH (Interstitial cells stimulating hormone) activates the leydig’s cells of testes to secretes androgens.
(b) Vas deferens is larger duct arises from cauda epididymis and reach up to seminal vesicles.
(a) In birds usually female is designated as ZW, being heterogametic and male is designated as ZZ being homogametic.
(b) Prostatic secretion contains substances important for sperm mobility notably albumin and proteolytic enzymes fibrenolysin and fibrinogenase.

Female reproductive system

(a) Seminal fluid has a pH about 7.4 and contains fructose, citrate, ascorbic acid prostaglandins and various enzymes. The fructose is a source of energy for the spermatazoa.
(a) The greater vestibular glands (Bartholin’s glands) are paired glands situated one on each side of the veginal opening. These glands are homologous to the bulbourethral (cowper’s) gland of male and secrete viscid fluid that supplements lubrication during sexual inter course.
(b) Seminal vesicles (uterus masculinus) are situated behind the bladder at the function of vas deferens and prostate gland. They are narrow long pouches with muscular tissue on their wall.
(b) Regner de graaf (1641-1673) discovered follicles in human ovary is 1671 and considered them to be eggs. Since graaf discovered follicles. They are also called graffian follicles.
(d) Cortex contains many small and large spherical or oval ovarian follicles. A fully matured follicle is called graafian follicle.
(a) Human egg or ovum is non cleidoic and alecithal. The ovum possesses three coverings-Inner plasma membrane, middle glycoprotein zona pellucida and outer cellular corona radiata with radially elongated scattered cells held in mucopolysaccharide
(b) Corpus luteum literally yellow body. The luteal cells secrete small amounts of estradiol hormone and significant amounts of the progesterone hormone. Corpus luteum also secretes relaxin hormone.
(b) Each ovary is surrounded by mesovarium or fold of peritoneum for suspending it to dorsal body wall.
(b) Graafian follicle develops under influence of FSH of anterior pituitary. Its follicular cells secrete estrogen. Rising level of estrogen decreases production of FSH and stimulates secretion of LH. The two cause the mature graafian follicle to rise to the ovarian surface and burst open releasing ovum.
(d) In rabbit, ovulation does not occur in the absence of copulation. So copulation induces the ovulation. Copulation provides neural stimulus for ovulation.
(c) Lining layer of uterus called endometrium (mucous membrane) is richly supplied with blood vesseles and tubular gland. Actual wall of uterus is myometrium. It is covered on outside by perimetrium.
(b) The ruptured follicle show proliferation of cells of membrana grenulosa, deposition of yellow pigment or lutein and formation of yellow body called corpus luteum. Corpus luteum secretes progesterone. Ultimately corpus luteum loses its yellow colour becomes changed to corpus albicans and then degenerated.
(a) Corpus luteum is formed after release of ova from graafian follicles and secretory in nature.
(b) Cervix is lower narrow part which opens in body of uterus by internal os and in vegina below by external os.
(c) The cavity of graffian follicle is antrum or follicular cavity having liquor folliculi and an eccentrically placed oocyte.
(b) The glands open on the nipple, the lactiferous ducts just under the nipple, the lactiferous ducts widen to form lactiferous sinuses, to store milk during location. A nursing mother produces 1 to 2 liters of milk perday.
(d) Collectively called as secondary sexual characters.
(b) The ovary remains attached to the abdominal wall by a ligament called mesovarium. The uterus is lie in the fold of peritoneum called mesometrium.
(b) Cessation of menstrual cycle is called menopause. Menopause occurs in females at the age of 45-50 years.
(a) There are two uteri in rabbit. So uterus is bicornute type.
(c) Uterus opens into an elastic muscular tube called vagina. Vagina is lined by a stratified squamous epithelium without any glands.
(d) The mammals other than primates show oestrous cycle while primates only show menstrual cycle.
(a) In the proliferative phase of menstrual cycle uterus have straight ducts they become coiled in luteal phase.
(a) Ovulation occurs under the influence of LH from pituitary gland.
(a) Fimbriated funnel is the modified proximal end of an oviduct as in frog. The oviduct of rabbit are short and less convoluted than those of frog. These are called fallopian or uterine tubes.
(a) The corpus luteum secretes progesterone hormone under the influence of LH.
(d) Oestrus comprises cyclic changes in female reproductive system of non-primate mammals.
(c) Vagina serves as birth canal during parturition.
(b) Since estrogen is secreted by the Graafian follicles from their internal theca.
(d) Bartholin’s glands are located in the female vagina, one on each side of the vaginal orifice.
(c) Corpus luteum is a yellow body formed from empty Graafian follicle. Macula lutea is a yellow spot on the retina lying exactly opposite to the centre of cornea.
(b) Estrogens are produced by the theca interna cells of graafian follicles. Estrogens regulate growth and development of female accessory reproductive organs. Secondary sexual characters and sexual behaviour.
(b) The ovum is ejected from the follicle near the end of proliferative phase i.e. 14^th day or midway during menstrual cycle.

Gametogenesis

(b) Discharge of a mature ovum from Graafian follicle is known as ovulation.
(c) Spermatogonia/oogonia are produced by mitotic cell division while spermatids and ova are produced after meiotic cell division.
(b) Acrosome forms a cap in front of nucleus containing lytic agent (lysin) which penetrates egg membrane during fertilization.
(b) Polar bodies are smaller cells produced during oogenesis that do not develop into egg cells.
(d) In the first, meiotic division of the frog oogenesis, the diploid primary oocyte divides into two unequal haploid daughter cell a large secondary oocyte and small first polar body.

Phase of Embryonic Development

(b) Teratology is the study of menstruals and foetal malformations.
(a) Graafian follicle is about 2.5 cm is diameter and has a secondary oocyte surrounded by a few lagers of follicular cells, that is nourishing cells formed from undifferentiated oogonia.
(c) Spermatogenesis is under control of growth hormone. secretion of both L.H. and FSH is under control of GnRH of hypothalamus.
(c) The “father of modern embryology” is Karl Ernst von Baer (1792 – 1876). In 1872 he saw mammalian ovum.
(c) Ejaculation or Seminal emmission is the forceful expulsion of semen during. Sexual intercourse. It passes through prostate gland and opens into urethra.
(d) Oogenesis is process of formation development and maturation of haploid ova from diploid germinal cells of ovary. Oogenesis comprises in three phase (i) Multiplication phase (ii) Growth phase (iii) Maturation phase.
(a) The process of formation of haploid ova from diploid germinal cells (2n) of the ovary called oogenesis.
(a) Von baer is called fathers of modern embryology who gave the rule of embryonic development of an organism.
(a) Spermatogenesis is the process of formation of haploid function spermatozoa from diploid germinal cells of seminiferous tubules.

Fertilization

(c) Sperm penetrates through egg wall in most of the organisms by the help of sperm lysin formed from acrosome.
(d) During maturation phase, the primary oocyte undergoes meiosis I Producing two haploid cells (n) the larger one is secondary oocyte and the smaller one is first polar body, meiosis II of secondary oocyte result in the formation of functional egg or ovum and a second polar body.

(c) In mammals (Rabbit and human beings), fertilization of the ovum occurs in fallopian tube or oviduct or uterine tube.
(d) Fertilization membrane prevents polyspermic fertilization by preventing further entry of spermetozoa.
(a) Hyaluronidase, corona penetrating enzyme and acrosin are collectively called sperm lysin and are released from the acrosome during acrosomal reaction after the sperm entry.
(d) Development of an egg (Ovum) into a complete individual without fertilization by a sperm is known as parthenogenesis.
(d) Oscar hertwig (1875) described the fusion of sperm and egg nuclei (fertilization) in sea urchin.
(c) Entry of sperm stimulates the secondary oocyte to start the suspended meiosis – II resulting in the formation of one ootid and 2 – 3 polar body. Ootid changes to become ovum, male and female pronuclei get mixed up. The process is called Amphimixis .
(d) Acrosome contains an enzyme hyaluronidase which breaks the covering of the ovum.
(b) In vertebrates they vary in size from 0.07 mm. The size of the egg chiefly depends upon the amounts of yolk reserves in it. Sharks and rays among fishes, reptiles and birds generally lay eggs of larger dimension. The egg of mammals are minute with very little yolk.
(d) The gametic fusion does not takes place, thus the genome of the ovum remains unaltered.
(a) Antifertilizin molecules present on the surface of spermetozoa. The antifertilizin are acid proteins with a fairly smaller molecule.
(b) Low temperature keeps the sperms alive for a fairly long period.
(a) These are egg laying animals in which most of the embryonic development of fertilized egg occurs out side the body of the mother, e.g., Insects, fishes, amphibians, reptiles birds etc.
(d) Such egg are not directly penetrated by the sperm. Here in such cases the sperm must penetrate through as special canal called micropyle or outgrowth left in the egg membrane the receptor cone.
(c) Cortical granules (Gulyas 1980) are extruded after fertilization to modify both plasma membrane and zona pellucida.
(a) Tail is very long tapering vibratile part of sperm, so movement of sperm is done by tail.
(a) Fertilizin is a chemical secretion of uppermost layer of egg. It is mucopolysaccharide or glycoprotein that attracts sperms.
(a) On fertilization egg becomes diploid (2n).
(b) The penetration of the sperm through the zona radiata is also supported by enzymetic substance called hyaluronidase (mucopolysacchrside hyaluronic acid) that is chemical.
(a) Fusion of sperm and egg pronuclei. The envelopes of the sperm and egg pronuclei degenerated and their chromosomes intermediate to form Synkaryon, called Karyogamy or syngamy.

Cleavage

(d) The egg laying mammals are known as prototherians. They have polylecithal eggs.
(d) In holoblastic, total or complete cleavage the entire egg divides by each cleavage furrow. It may be (i) equal holoblastic (ii) unequal holoblastic.
(b) An unfertilized egg is pricked with a microneedle, it will start dividing that is called artificial or induced parthenogenesis.
(c) Blastopore will give rise to future anus in frog.
(b) This segmentation cavity is known as blastocoel.
(d) Human egg has 22 autosomes and one chromosome. It is a haploid cell.
(a) Microlecithal or Alecithal or Oligolecithal or mesolecithal eggs containing a small amount of yolk or without any yolk e.g., starfish Amphioxus, eutherion mammals (Rabbit and man)
(c) Telolecithal egg – yolk is concentrated towards vegetal pole the nucleus and major part of cytoplasm is displaced to animal pole as in mesolecithal and macrolecithal egg of vertibrates.
(a) Cleidoic egg are the egg of reptiles and birds that are insulated from the environment by albumen membranes and shell. The calcareous shell present around the eggs of bird is porous and allows diffusion of o₂ and co₂.
(a) Determinate cleavage which produces a complete embryo only if all the blastomere remain together. Each blastomere has its characteristic position and unalterable fate. This is also called mosaic development e.g., Nematoda, Mollusca.
(b) Superficial blastula this is also called periblastula formed by meroblastic superficial cleavage as in insect. centrolecithal eggs develop to superficial blastula. It consist of a single layer of epithelial cells surrounding the centrally placed yolk. There is no blastocoel e.g., insect.
(b) Cleavage in the fertilised egg in humans occurs in the fallopian tube (oviduct) during the conduction of zygote towards uterus.
(b) The second cleavage is right angle to first one again meridional result in four blastomeres, identical with respect to cytoplasm pigment and yolk gradient.
(a) Mammalian eggs are alecithal. Eggs containing a small amount of yolk or without yolk is called alecithal, e.g., eutherians mammals.
(b) Migration and spreading of micromeres over the embryo is known as epiboly.
(a) Pseudocoelom is a persistent blastocoel lacking a definite mesoderm lining.
(c) The yolk is concentrated on vegetal pole.
(a) Stereoblastula is a solid blastula with no blastocoel composed of densely packed large sized cells. e.g., cnidaria, Annelida (Nereis) and some molluscs.
(c) Tertiary egg membrane are lacking in mammals with the exception of prototherian. It is secreted by the oviduct or accessory female reproductive organ.
(c) During mosaic development the cytoplasm of blastomere differentiate in the early stages of development with reference to the tissue of the adult.
(a) The active cytoplasm contains germinal vesicle and allows easy passage to the male pronucleus.
(c) When the turn of spiral is clockwise, it is termed dextral and when it is anticlockwise, it is called synstral.
(c) Blastula is made up of the cells called blastomeres.
(a) The calcareous shell present around the eggs of birds in porous and allows diffusion of oxygen (O₂) and carbon dioxide (CO₂).
(c) In polylecithal eggs cleavage becomes meroblastic due to the presence of enormous yolk.
(a) The ratio of nucleus to cytoplasm is very low at the beginning of cleavage, but at the end it is brought to the level found in ordinary somatic cells.
(c) Disc shaped blastula (Discoblastula) is formed by meroblastic discoidal cleavage as in fishes, reptiles, birds and egg laying mammals. The disc formed is called blastoderm.
(c) At least 94% of shell is made of calcium carbonate. Calcium deficiency results in the formation of an egg with soft shell.
(b) The theory of organizer (inductor) in amphibia was introduced by Spemann is 1938. He was awarded nobel prize for this work.
(a) Swammerdam (1738) observed the first cleavage of frog.
(c) The albumen, shell membranes and outermost calcareous shell of reptiles and birds are the best examples of tertiary egg membranes.
(a) Zygote Morulla

Blastulla gastrula

(a) Cleavage division result in formation of a 32 to 64 celled solid morula or hollow blastula in some cases.
(b) Microlecithal or oligolecithal eggs are small sized eggs with very small amount of yolk e.g. in Hydra. Sea urchin, Amphioxus, marsupials, eutherians.
(c) In telolecithal egg, yolk is concentrated towards vegetal pole, the nucleus and major part of cytoplasm is displaced to animal pole as in mesolecithal and macrolecithal eggs of vertibrates.
(d) Blastopore occurs in gastrula and open into archentron.
(c) Discoidal cleavage found in macrolecithal and highly telolecithal eggs of reptiles, birds, and monotreme mammals.
(c) As the amount of nutritive fluid increases in blastocoel, morula enlarges and takes the form of a cyst and is now called blastocyst e.g., man, monkey.
(b) Meroblastic is also called partial or incomplete cleavage occurs in macrolecithal and teloleicthal egg. The cleavage furrow divides the small amount of active cytoplasm of animal pole most of yolky portion of vegetal pole or central area of egg remains undivided.
(d) The egg of cockroach is centrolecithal type i.e., yolk present in the centre.
(b) All eggs are haploid and carry XX as genotype.
(d) The fifth cleavage involves two simultaneous latitudinal divisions resulting in the formation of 32 blastomeres.
(c) The egg of frog is telolecithal. In this type of egg. yolk is aggregated at one pole.
(c) Macrolecithal or polylecithal eggs contain very large amount of yolk eg. monotremata (Prototherian mammals) reptiles birds etc.
(a) Cleavage of frog is unequal holoblastic occurs in mesolecithal or telolecithal type of eggs. This produces unequal sized blastomeres called micromeres and megameres eg. amphibians (Frog).
(b) pattern of cleavage in frog’s egg is holoblastic and unequal because this produces unequal sized blastomeres called micromeres and macromeres.
(c) Yolk is concentrated in the centre of the ovum with cytoplasm surrounding it as in macrolecithal eggs of arthropoda.
(d) Cleavage start after fertilization upto late blastula.
(a) Frog egg consists of pigmented animal hemisphere and yolky vegetal hemisphere.
(a) Presumptive or prospective areas are found in blastula and able to define the fate map.
(d) Very less amount of yolk is found in eutherian mammals.
(c) Because it is made up of hard .
(c) In birds and other polylecithal egg containing animal division are restricted to a small part of cytoplasm and nucleus in animal pole of egg. Such type of cleavage is termed as meroblastic cleavage.
(c) Cleavage is a series of mitotic cell divisions that increase the number of cells but does not change the size of the original mass of zygote.

Implantation in Gastrulation

(d) Mammalian embryo remains connected by means of placenta with the mother’s body to receive nutrition and oxygen supply.
(d) Implantation occurs in viviparous animals.
(d) Implantation is the attachment of blastocyst to the uterine wall. It occurs after 7 days of fertilization.
(a) The thyroid is an endodermal derivative.
(c) New cavity formed during gastrulation is archenteron (gastrocoel) opened outside through blastopore.
(a) Nervous system develops from ectodermal layer.
(a) By the end of gastrulation, blastocoel will be reduced. A yolk plug of endodermal origin closes the blastopore.
(d) Formation of notochord is known as notogenesis.
(c) Involution is the process of rolling or turning in of the surface cells into the interior of the embryo. It occurs in frog blastula.
(d) Gastrulation is the process of the embryonic development during which cell movements establish the three primary germinal layers namely ectoderm, mesoderm and endoderm.
(c) Connective tissue, bone and cartilage, heart, blood, muscles and gonads are formed from mesoderm.
(c) The archenteron is primitive gut lined by the endoderm.
(d) Transfomation of the blastocyst into the gastrula with primary germ layer by the rearrangement of the cells is called gastrulation.
(d) During gastrulation the dorsal lip of blastopore appears behind the grey crescent area.
(a) Brain is derived from ectodermal layer.
(a) A three layered larva, gastrula is formed and cell mass move from surface of blastula by morphogentic movements.

Neurulation and Organogenesis

(c) Hans Spemann of Germany won the Nobel prize in 1935 for his discovery of organiser effect in embryonic development.
(c) The gastrulation is followed by neurulation during which the premordium of nervous system, the neural plate is laid down.
(c) The first maturation decision is reductional or meiotic. Hence, the primary spermatocyte divides into two haploid daughter cells called secondary spermatocytes.
(c) In vertebrate vertebral column develops from embryonic notochord.
(a) Internal ear develops from embryonic ectoderm layer.
(b) In protostomia mouth is derived from the blastopore of embryo and anus is formed at the apposite end.
(b) Posterior side of future tadepole is represented by the side of frog’s embryo bearing the yolk plug.
(a) Eye (ratina, lens and cornea) derived from embryonic ectoderm.
(a) Embryonic cells differentiate at an early stage and from an outer layer of cells the ectoderm and an inner layer the mesoderm is formed and these three germ layer give rise to all the tissues of the developing embryo is developed from mesodermal layer.

Extra embryonic membrane

(a) The space between the embryo and the amnion is called the amniotic cavity which is filled with amniotic fluid. The amniotic fluid prevents desiccation of the embryo and acts as a protective cushion that absorbs shocks.
(d) The yolk sac is nonfunctional in human beings except that it functions as the site of early blood cell formation.
(c) Allantois acts as an extraembryonic lung by supplying the embryo with oxygen.
(b) The original function of the allantois as a urinary bladder becomes altogether lost.
(c) Allantois is a fold of splanchnopleur developed from the hind gut of the embryo.
(b) In primates including human beings only chorion forms the placenta (chorionic placenta)
(b) Trophoectoderm form placenta which help to draw food for the developing cells
(c) Extra embryonic membranes (foetal membranes) are concerned with protection, respiration, excretion, and nutrition of developing embryo.
(d) Amnion provides a kinds of private aquarium to the embryo and protects it from mechanical shock and desiccation.
(a) In eutherian mammals chorion and allantois together form placenta.
(b) Egg shell is porous; if it is covered, the passage of air will be blocked.
(a) The amnion and the fluid filled amniotic cavity it enclose, enlarge and nearly surround the embryo.
(c) Chorion is the outermost extra embryonic membrane of amniotes enclosing the embryo and all its other membranes.
(c) The main function of allantois of mammlian embryo is nutrition. It is also helps in respiration and excretion.
(c) Peripheral cells of morula become the trophoblast (trophoectoderm) cells which later produce the four extra embryonic membranes.
(c) Man has four foetal membranes viz-Amnion, Chorion, Allantois and yolk sac.

Placenta

(c) Placenta is universally present in eutherian mammals.
(d) Role of placenta is provide essential requirements for growth of embryo.
(d) Placenta is formed from allantois and chorion e.g., Eutherian mammals (Rabbits)
(c) Placenta is formed by interlocking of both foetal as well as maternal tissue.
(c) Zonary placenta – villi occur in one or two transverse bands eg. Tiger, Lion, Cat, Dog, Elephant.
(c) Placenta is the region where foetus receives nourishment from mother’s blood.
(b) Viruses have less molecular weight than plasma proteins and blood cells.
(c) Uterine epithelium, uterine connective tissue and endothelium of maternal blood vessells are absent in haemochorial placenta found in human being.
(a) Placenta is the special semipermeable structure through which the exchange of materials between foetal and maternal circulation occurs.
(d) Nerves are not found in placenta.
(c) Word endometrium is composed of endo and metra which in Greek language means within and uterus respectively i.e., within uterus. Endometrium is the glandular lining of the uterus in mammals. It thickens in response to progesterone secretion during ovulation and is sloughed off in menstruation.
(d) In human placental villi remain restricted to a small disc – shaped area (discoidal) attached to the utrine wall.
(a) Umbilical cord is a tubular connection covered with a connective tissue sheath through which connect the embryo with the chorion of placenta.

Gestation Period and parturition

(d) About 669 days.
(d) Mouse has a gestation period of about 19–20 days.
(c) Gestation period is the duration between fertilization and parturition.

Development of frog

(d) Paedogenesis refers to development of gonads and production of young ones by larval or preadult animal.
(b) Complete metamorphosis includes; egg ® larva ® pupa ® imago and adult.
(c) Thyroxin is responsible for the metamorphosis.
(c) Thiourea is an antithyroid drug, it inhibits metamorphosis of frog.
(c) Archenteron formation begins in early gastrula stage.
(a) Tail is present in larval stage of frog but it becomes degenerated in adult frog.
(b) During early embryonic development of frog a blastula stage comes after morula stage which contain a small irregular excentric space or cavity called blastocoel or segmentation cavity apper in the animal hemisphere.
(c) The third cleavage is horizontal (latitudinal or transverse) but not equatorial it is decidedly nearer the animal pole and consequently this division results in the formation of 8 cells.
(d)Neoteny refers to retention of a larval or embryonic trait in the adult body.
(b) A gray crescent appears in the equitorial zone geometrically opposite to the sperm entrance.
(c) Fertilization in frog is external taking place in water.
(a) Grey cresent is the crescentic surface area in the animal hemisphere of frog which develop into dorsal lip of future blastopore.

Critical Thinking Questions

(c) Testes in mammals are present out side the abdominal cavity because maturation of sperm needs low temperature. The temperature of scrotum is below (2 to 4°C) than abdominal cavity.
(b) Cryptorchidism is nondescent of testes in scrotum, person becomes sterile.
(d) Sertoli cells are non-gametic cells in the seminiferous tubules which provide nourishment for developing sperms.
(b) A mass of cells of the membrana granulosa which covers the ovum is called cumulus ovaricus.
(a) Clitoris is small organ consisting of erectile tissue and is homologous to the penis of the male.
(a) Corpus luteum which secretes progesterone is responsible for the maintenance of pregnancy.
(c) Implantation is attachment of early embryo with the wall of uterus. It occurs after 7 days of fertilization.
(d) Degeneration and reabsorption of an ovarian follicles before its fully matures and ruptures are called atretic follicles.
(a) Progesteron is secreted by corpus luteum and formation of corpus luteum is stimulates by LH.
(a) The uterine lining dies due to the deficiency or reduced level of progesterone in blood and is sloughed off. Blood vessels rupture, causing bleeding.
(b) Menstrual cycle consists of menstrual phase, the pre-ovulatory phase, ovulation and post ovulatory phase.
(b) When the acrosome of the spermetozoa touches the surface of the egg, the cytoplasm of the egg bulges forward forming receptive cone or fertilization cone.
(d) Dizygotic twins are also called fraternal or nonidentical twins, formed by simultaneous fertilization of two different ova by two different sperms.
(c) It is a protein (Mol. wt. 1000) consisting of acidic amino acids. Due to its presence sperm is attracted towards egg of same species by chemotaxis.
(a) A sort of compound is formed between fertilizin and antifertilizin of same species i.e. it is species specific.
(a)It makes the cell metabolically active and acts as a stimulus for the egg to undergo cleavage.
(a) Acidic pH kills the sperm or reduces their activity.
(d) In microlecithal eggs or alecithal eggs, the cleavage results in the production of closely packed blastomeres. The stage in which solid mass of blastomeres appears is said to be morula, whereas blastula is hollow with a cavity known as blastocoel.
(d) In oligolecithal eggs viz. Amphioxus, holoblastic cleavage takes place and in mesolecithal eggs viz. fishes and amphibians, unequal holoblastic cleavage (except I and II) is found.
(a) Presumptive areas are evident in blastula. In gastrula germ layers are formed. In post gastrula organogenesis starts.
(b) Blastocoel is filled with an albuminous fluid secreted by surrounding cells.
(b) Unequal holoblastic cleavage occurs in mesolecithal or telolecithal type of eggs. This produces unequal sized blastomeres called micromeres and macromeres.
(b) No growth of the embryo occurs during cleavage because there is an increase in the number of cells and progressively they decrease in size.
(b) A solid ball of cells showing resemblance with mulberry is formed by the cleavage of zygote. This is known as ‘morula’.
(d) Discoblastula is disc shaped blastula which is formed by meroblastic discoidal cleavage as in fishes, reptiles, birds and egg laying mammals.
(c) In patterns of spiral clevage, blastomeres are arranged in a spiral manner e.g., platyhelminthes, Annelida and most mollusca.
(b) Cleavage is a series of rapid mitotic divisions of the zygote which convert the single called zygote into multicellular structure in which no any growth occurs in cells.
(c) Total no. of cells produced = 128

No of cleavage = n, if we put the value of n = 7, then cells.

(b) The process of attachment of the blastocyst on the endomatrium of uterus is called implantation.
(c) Cell movements i.e. morphogenetic movement is the most important characteristic of gastrulation. As a result of which (a) and (b) takes place.
(b) ‘Gastrulation‘ word is derived from Greek word `gaster‘ meaning stomach and according to McEwen (1923), gastrulation refers to the formation of the primordial gastric gut or cavity called the archentron.
(c) In gastrula, new cavity formed during gastrulation is archenteron opened outside through blastopore.
(d) Gastrulation is characterised by the presence of archenteron, three germinal layers (ectoderm, mesoderm and endoderm) and morphogenetic movements.
(b) Blastula differentiate into various regions and cells (blastomeres) of a particular region form a particular part of adult body, hence these areas are called presumptive areas and at this stage if cells of a particular area are removed the adult lacks a particular part from its body.
(b) In embryonic stage, erythropoiesis (formation RBCs) is occurs mainly liver and spleen.
(c) Gut is endodermal in origin.
(b) Establishment of polarity in developing embryo along different axis is induced by organizer phenomenon.
(a) Somatopleure is a double layered tissue formed by the fusion of the ectoderm with the somatic or outer layer of mesoderm in the vertebrate embryo. It gives rise to parts of body wall and to amnion and chorion.
(d) Extraembryonic membranes are formed outside the embryo from the trophoblast only in amniotes (reptiles, birds and mammals) and perform specific functions.
(b) Chorion is outer most embryonic membrane and always participates in placenta formation.
(a) Amnion provide protection against shock and desiccation which is already provided by water in frogs, hence amnion is absent in it.
(d) Maximum number of barriers present in some mammals is six, but in human beings only three barriers are present.

Assertion and Reason

(e) The organs which perform important functions in reproduction but neither produce gametes nor secrete sex hormones, are called secondary sex organs. These include the prostate, seminal vesicles, vas deferens and penis in males and the fallopian tubes, uterus vagina in females. Primary sex organs are those organs which produce gametes or secrete sex hormones, for examples, testis is the primary male sex organ. It produces spermatozoa by undergoing a process called spermetogenesis in seminiferous tubules and secretes the male sex hormone testosterone from interstitial cells.
(a) Embryonic development includes a definite series of phases which are fundamentally similar in all sexually reproducing organisms, and transform a one-celled zygote to a multicellular and fully formed developmental stage till hatching or birth such a remarkable similarity of embryonic development proves that all metazoans are interrelated and have common ancestory. Embryonic development involves five dynamic changes and identifiable processes these are – Gametogenesis, fertilization, cleavage, Gastrulation and organogenesis.
(b) Entrance of a single sperm into an oocytes is called monospermy generally monospermy found in most of animals. Cortical granules are extruded in the perivitelline space by exocytosis and some of these are attached along inner surface of vitelline membrane which now thickens and becomes impervious to any other sperm entry. It is now called fertilization membrane. It prevents the polyspermy.
(a) Penetration of sperm is a chemical mechanism. In this acrosome of sperm undergoes acrosomal reaction and releases certain sperm lysins. Which dissolve the egg involves locally and make the path for the penetration of sperm sperm lysins are acidic proteins. These sperms lysin contain a lysing enzyme hyaluronidase which dissolves the hyaluronic acid polymers in the intercellular spaces which holds the granulosa cells of corona radiata together; corona penetrating enzyme and acrosin. Then it dissolves the zona pellucida only sperm nucleus and middle piece enter the ovum.
(a) During cleavage, there is no growth during interphase so the size of blastomeres becomes smaller and smaller. So the cleavage is called fractionating process. In morula stage the cell divide without any increase in size because in cleavage there is increases in number of blastomeres but decreases in size of blastomeres.
(d) The nuclear-cytoplasmic ratio goes on increasing as the cleavage progress. DNA synthesis occurs very rapidly during cleavage but there is no cytoplasmic synthesis. The cytoplasmic material are rapidly used in DNA replication.
(b) The process of attachment of the blastocyst (mammalian blastula) on the endometrium of uterus is called implantation.
(a) Gastrulation is a process by which blastocyst is changed into a gastrula larva with three primary germ layers. In this cells of blastodermic vesicle visibly move in small masses to their final and predetermined positions. These movements are interdependent and are called morphogenetic movements.
(b) Development of an organism from non-sexual reproductive units like buds fragments etc. is called blastogenesis. In asexual reproduction there is no formation and fusion of gametes.
(a) New individuals produced are genetically similar to the parent and also to each other as mitotic divisions produce no variations. The trophoblast is developed from the superficial layer of morula stage with control implantation and endometrium around the embryo shows the first sign of a decidual cell reaction.
(a) Amoeba shows multiple fission it is a type of asexual reproduction in which the parental body divides into many daughter cells simultaneously during the unfavourable conditions to increase the chances of survival of daughter cells.
(c) Sexual reproduction is advantageous than asexual reproduction because in sexual reproduction progeny are genetically different from the parents as variations appear due to new combinations of genes during crossing over. Chance segregation of chromosomes and chance fusion of gametes. So it plays important role in evolution.

Sexual reproduction is slow mode of reproduction while asexual reproduction is rapid mode of reproduction.

(c) Natural porthenogenesis occurs in honey bee. The queens and worker are developed from fertilized ova While drones (male) are produced parthenogenetically.
(a)In human male, one pair testes are present in thin walled skin pouches called scrotal sac (so are extra abdominal) hanging from lower abdominal wall between the legs. Testes is held in position in scrotum by gubernaculum and spermatic cord. Scrotal sac act as thermoregulators and keep the testicular temperature 2°C lower than body temperature for normal spermetogenesis, as high abdominal temperature kills the spermatogenic tissue.
(c) Urethra in human male act as urinogenital canal as it carries urine, sperms and secretions of seminal vesicles, prostate and cowper’s glands.
(a) Labia minora fuse anterioly to form a skin fold called prepuce infront of a small erectile organ the clitoris which is homologous to penis, and both are supported by corpora cavernosa and highly senstive.
(c) At puberty in human male is controlled by male sex hormone testosterone which is secreted by interstiteal or leydig’s cells of testes so secondary sexual characters develops and at puberty secretion of testosterone is increase.
(b) Infundibulum is funnel shaped end fallopian or oviduct. The funnel is called oviducal funnel or fallopian funnel. Its free end bears a number of finger like processes called fimbriae, but graafian follicle of ovary is with secondary oocyte hanging in cavity, called antrum.
(b) After ovulation, a raptured follicle turns into a yellowish solid mass of cells called corpus luteum, these secretes the female sex hormone progesterone which maintains the pregnancy.
(b) In the female breasts size increases after puberty under the stimulation of estrogens. Size of breasts is further increased during pregnancy and after childbirth under the stimulation of prolaction hormone.
(d)Vegina is tubular female copulatory organ. Passageway for menstrual flow as well as birth canal. Vegina receives semen from male during mating but fertilization (fusion of gametes) in occurs in fallopian tube.
(a)Claspers of cartilaginous fishes (sharks) is one pair between the pelvic fins. Claspers are analogous to penis of human male both act as copulatory organ and transfer the sperm into female.
(d)Perinial gland are found in rabbit not in human beings. These are a pair of dark elongated scent glands lying behind the cowper’s glands. These are sex attractant secreting glands, its smell serves as sex attractant for the female.
(d) Primary spermatocytes of testes are diploid and formed by mitotic division in the spermatogonium.
(d) Metamosphosis of spermatid to sperms is termed spermiogenesis or spermetoleosis. The spermatids mature into spermatozoa in deep folds of the cytoplasm of the sertoli cells (nurse cells) which also provide nourishment to them.
(c) During fertilization, only one sperm head enters into ovum and remaining parts of body degenerates. If several spermatozoa hit the egg at same time, even then only one can get entry into egg because after entry of one sperm, the egg becomes imprevious to other sperms.
(b) Zygote divide vertically to form two blastomeres. This is followed by a vertical division and a horizontal division. Now, several divisions occur forming equal sized blastomeres called morula. There is no increase in size of cells. Zona pellucida is a transparent non cellular layer surrounding egg cell. It remains undivided till the cleavage is complete.
(c) Eggs containing a small amount of yolk or without any yolk are known as mirco lecithal/alecithal/oligolecithal/ mesolecithal eggs. Such eggs are found in starfish, Amphioxus, eutherian mammals including rabbit and human beings. In such egg equal holoblastic cleavage takes place in which equal or approximately equal sized blastomeres are produce.
(c) The incomplete metamorphosis as occurs in cockroach is called gradual metamorphosis or paurometaboly. The interval between 2 successive moulting is called stadium and the form assumed during a stadium is called instar. The young insect which assumes the adulthood in insects is called imago. Imago donot resemble the adult in all characters.