Which of the following is true for a recessive disease in Family A and B?

• In family A, both the parents are homozygous recessive

• In family B, both the parents are heterozygous dominant.

• In family B, both the parents are heterozygous recessive

• In family A, both the parents are heterozygous recessive.

142.

Assertion: In a pedigree analysis, <5> represents five unaffected offsprings.

Reason: In a pedigree analysis, the offsprings are numbered with arabic numerals (1, 2, 3 .....) and a generation is numbered with roman numerals (I, II, III...).

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion: Hb^s Hb^s denotes the homozygous condition for sickle-cell anaemia.

Reason: It occurs due to substitution of glutamic acid by valine at the 6 position of (B-chain of Hb.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : Only a boy child could be born with a substitution of glutamic acid by valine on 6 codon of beta-chain of haemoglobin.

Reason : The gene for the above mutation is found on Y-chromosome.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are hue but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Which of the following disorders are caused due to recessive autosomal mutations?

• Turner"s syndrome and sickle cell anaemia

• Edward's syndrome and Down's syndrome

• Cystic fibrosis and phenylketonuria

• Alzheimer's disease and Huntington's chorea

Which of the following diseases is also called Christmas disease?

• Sickle-cell anaemia

• Haemoglobinuria

• Myocardial infarction

• Haemophilia- B

Assertion : Antirrhinum is a good example to understand incomplete dominance.

Reason : Heterozygotes show characteristics of both the alleles.

• If both assertion and reason are true and reason is the correct explanation of assertion

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false

• If both assertion and reason are false.

Which of the following is correct

• Henking discovered the small Y-chromosome.

• Drosophila also shows XX-XY sex determination like human.

• Birds have ZZ-ZW sex determination, where females are ZZ & males are ZW.

• Grasshoppers show XX-XY sex determination

Percentage of recombination between A and B is 9%, A and C is 17%, B and C is 26% , then the arrangement of genes is

• ABC

• ACB

• BCA

• BAC

Which of the following conditions represents a case of co-dominant genes?

• A gene expresses itself, suppressing the phenotypic effect of its alleles

• Genes that are similar in phenotypic effect when present separately, but when together interact to produce a different trait

• Alleles, both of which interact to produce a trait, which may or may not resemble either of the parental types

• Alleles, each of which produces an independent effect in a heterozygous condition