The F2 genotypic ratio of a monohybrid cross is:
1. 1 : 1
2. 3 : 1
3. 1 : 2 : 1
3. 9 : 7
In a test cross, the plant expressing the dominant phenotype is crossed with the plant:
1. Which is heterozygous dominant
2. Which is heterozygous recessive
3. Which is homozygous recessive
4. Which is homozygous dominant
Which of the following is not true for the Law of Dominance given by Mendel?
1. Characters are controlled by discrete units called factors.
2. Factors occur in pairs.
3. In a dissimilar pair of factors one member of the pair dominates the other.
4. The alleles show blending at the time of fertilization
What is the F2 genotypic ratio in cases of incomplete dominance?
1. 1 : 1
2. 3 : 1
3. 1 : 2 : 1
4. 1 : 1
Blood group antigens are:
1. Carbohydrates present in plasma
2. Carbohydrates present on the surface of RBCs
3. Plasma proteins
4. Proteins present on the surface of RBCs
What can be the blood groups of progeny whose father and mother are of AB and O blood group respectively?
1. A and B only
2. AB only
3. All except O
4. A, B, AB and O
“Chromosomes, which are seen in all dividing cells and pass from one generation to the next, are the basis for all genetic inheritance”.
This statement is credited to:
1. Watson and Crick
2. Hershey and Chase
3. Sutton and Boveri
4. Meselson and Stahl
T. H. Morgan worked on the fruit fly, Drosophila melanogaster . Which of the following is not an advantage of this fly?
1. They could be grown on simple synthetic medium in the laboratory.
2. They complete their life cycle in about two years, and a single mating could produce a large number of progeny flies.
3. There was a clear differentiation of the sexes – the male and female flies are easily distinguishable.
4. It has many types of hereditary variations that can be seen with low power microscopes.
When the two genes in a dihybrid cross are situated on the same chromosome:
1. The proportion of parental gene combinations was much higher than the non-parental type.
2. The proportion of parental gene combinations was much lesser than the non-parental type.
3. The proportion of parental gene combinations was equal to the non-parental type.
4. Only recombinants are formed.
During his observation of spermatogenesis in few insects, Henking found that a nuclear structure was received by 50 % of the sperms. He called this structure as:
1. X – body
2. Y – body
3. X – chromosome
4. Y – chromosome