An inherent trait of organisms is the prodigality of reproduction; as a result, the number of organisms increases in a geometric proportion - justify the validity of the statement with two proper examples.

With the help of a checkerboard show the phenotypic ratio of offspring produced in F2 generation as a result of a cross between a pure black coloured and rough-haired guinea pig and a pure white and smooth-haired guinea pig. "Father plays the main role in the determination of sex of the offspring" - justify the statement with the help of a checkerboard. [3+2=5] OR Write three reasons behind Mendel's success. Establish a relationship between phenotype and genotype with the help of proper examples. [3+2=5]

In spite of being pure in respect of one trait, what else could an organism be in respect of another trait?

Match the words in column-A with the most appropriate words in column B and re-write the correct pair mentioning the serial no. of both columns COLUMN - A COLUMN - B 1. Meninges (a) Decrease in the number of digits in the legs 2. Sexual reproduction (b) Submergence of islands 3. Roller tongue (c) Centromere 4. Evolution of the horse (d) Telomere 5. Environmental problem of Sundarban (e) Protects brain and spinal cord from mechanical injury 6. Attaches chromosome with spindle fibre (f) Controlled by autosome (g) Occurs through the production of gametes and their union

Which would be the genotypic and phenotypic ratio in the F2 generation of a hybrid cross in case of incomplete dominance? (a) 2 : 1 : 1 (b) 1 : 1 : 1 (c) 1 : 2 : 1 (d) 1 : 2 : 2

Which two of the following genotypes represent the genotype of a pea plant with yellow coloured and wrinkled seed? (a) YYr, Yy (b) YYRr, YRR (c) yRR, yyRr (d) YYRR, yyrr

With the help of an example explain how the phenotypic and genotypic ratios found in F2 generation of certain hybrid crosses indicate exception to Mendel's first law of heredity.

Write two causes behind Mendel's success in conducting experiments on heredity.

Prove the authenticity of the statement — "The phenotypic and genotypic ratio remain identical in case of Incomplete Dominance".

In which of the following crosses, will the F1 generation seed's tall and dwarf traits appear in a 1:1 ratio? (a) Tt x Tt (b) TT x Tt (c) TT x tt (d) Tt x tt

What will be the phenotypic ratio of progeny obtained from the hybridization between YyRR and YYrr genotypes? (a) 2:1 (b) 1:2 (c) 2:2 (d) 1:4

If a population undergoes three generations, and if each generation consists of only males, what is the probability that females will be present in the fourth generation? (a) 100% (b) 0% (c) 50% (d) 75%