2021

A phenomenon is termed parthenogenesis when                                                                                                 [CBSE PMT 1990]              (a)   Artificial fertilization occurs              (b)   Egg is fertilized...

          Reproduction and its type Which are exclusively viviparous                          [AFMC 1986]              (a)   Bony fishes                          ...

“Sertoli cells” in human testis are found in [CPMT 1980, 83, 94,99; DPMT 1986; AFMC 2002]              (a)   Seminiferous tubules...

Penetration of sperm is a chemical mechanism. In this acrosome of sperm undergoes acrosomal reaction and releases certain sperm lysins...

(iii) Mucous membrane : It is the innermost layer. This layer is made up of ciliated columnar epithelium and the...

  Reproduction and its type Reproduction : Reproduction is the ability of living organism to produce a new generation of...

Histones are synthesised during [CBSE PMT 1992]              (a)   Mitosis                                   (b)   S phase              (c)   G1 phase                                (d)   G2 phase...

  Growth Meaning and definition of growth : Growth is an important properties of all living organisms. All organisms grow...

  Reproduction is the process of formation of new individuals from pre-existing ones. It is the means of multiplication and...

Pollen embryoids were discovered by (a)   Guha and Maheshwari      (b)   Steward and White (c)   Konar and Natraja              (d)   Nitsch and...

Growth can be defined as a vital process which brings about irreversible permanent change in any plant or its part...

  Reiter first used the term ecology in 1868. Ernst Haeckel (1886) first correctly defined ecology as “the science dealing...

  Ecological plants groups Water as an important ecological factor was first recognized by Warming. On the basis of water...

  The word ecosystem was coined by A.G. Tansley in 1935. According to Odum an ecosystem is the basic fundamental...

Change in physical, chemical or biological characteristics of air, water and land that has the potentiality to harm human life,...

  Anything which is useful to man or can be transformed into a useful product or can be used to...

  Biome Definition : Each of the major terrestrial ecosystems or distinctive terrestrial areas with their group of climax plants...

Biodiversity and Wild Life Conservation Endemic plants are those which are  [BHU 1978; CPMT 1999]              (a)   Cosmopolitan in distribution...

The ‘‘environment as a self sustaining system’’ is mainly preserved by              (a)   Man                                         (b)   Animals              (c)   Trees                                      (d)  ...