Heterozygous and Homozygous

Q.

what is a pure line?

Q.

What is stabilizing selection?

Q. Inbreeding depression is:

1. Reduced motility and immunity due to close inbreeding
2. Decreased productivity due to mating of superior male and inferior female
3. Decrease in body mass of progeny due to continued close inbreeding
4. Reduced fertility and productivity due to continued close inbreeding

Q. Assertion : A single outcross between a superior animal of the inbreeding population and another superior animal of an unrelated population of the same breed can overcome inbreeding depression.

Reason : Crossing unrelated animals decreases the chances of homozygosity in progeny.

1. Both assertion and reason are true, and reason is the correct explanation for assertion
2. Both assertion and reason are true, and the reason is not the correct explanation for the assertion
3. Assertion is true statement and reason is a false statement
4. Both assertion and reason are false

Q. Inbreeding is carried out in animal husbandry because it

1. increases vigour
2. improves the breed
3. increases heterozygosity
4. increases homozygosity

Q. Which is true about inbreeding?

1. It is necessary if we want to evolve a pureline in any animal
2. It exposes harmful recessive genes
3. It increases homozygosity
4. All of the above

Q. Which is true about inbreeding?

1. It is necessary if we want to evolve a pureline in any animal
2. It exposes harmful recessive genes
3. It increases homozygosity
4. All of the above

Q.

Select the incorrect statement.

1. Inbreeding increases homozygosity.

2. Inbreeding is essential to evolve pure lines in any animal.

3. Inbreeding selects harmful recessive genes that reduce fertility and productivity.

4. Inbreeding helps in the accumulation of superior genes and the elimination of undesirable genes.

Q. Inbreeding is carried out in animal husbandry because it

1. increases vigour
2. improves the breed
3. increases heterozygosity
4. increases homozygosity

Q.

Selection of homozygous plant is:

1. Mixed selection

2. Mass selection

3. Pure line selection

4. None of these

Q. Match the following terms in genetics to their respective defining words.

1. Identical alleles
2. External appearance
3. Genetic makeup
4. Different alleles

Q. When a cross is conducted between black feathered hen and a white feathered cock, blue feathered fowls are formed.When fowls are allowed for interbreeding , in $F-2$ -generation , there are 20 blue fowls .What would be the number of black and white fowls ?

1. Black 20 , white 20
2. Black 10 , white 20
3. Black 20 , white 10
4. Black 10 , white 10

Q. Differentiate between Broad-sense heritability and Narrow-sense heritability.

Q. Within the squirrel population at City Park, $16$% show the recessive phenotype of a curled tail $\left(tt\right)$.

1. $0.08$
2. $0.24$
3. $0.36$
4. $0.48$
5. $0.64$

Q. Inbreeding increases

1. dominance
2. recessiveness
3. homozygosity
4. heterozygosity

Q. Which is true about inbreeding?

1. It is necessary if we want to evolve a pureline in any animal
2. It exposes harmful recessive genes
3. It increases homozygosity
4. All of the above

Q. Rewrite and complete the following sentence by inserting the correct word in the space indicated.

Phenotype is the observable characteristic which is .................controlled.

Q.

why Pure line selection has no association with natural selection?

Q. Inbreeding increases

1. dominance
2. recessiveness
3. homozygosity
4. heterozygosity

Q. Human earwax texture is determined by a single gene with two alleles, wet and dry. Dry is recessive and wet is dominant.
Evidence suggests that the dry allele first appeared in Eastern Asia about 2, 000 generations ago. The frequency of the dry allele in a European population is .15. What percentage of this population is expected to have the wet earwax phenotype?

1. 0.85
2. 0.26
3. 0.72
4. 0.02