Multiple Choice QuestionsAssertion: A middle aged woman is reported to have small breasts and undersized uterus.
Reason: Her genotypic analysis shows XO condition of allosomes.
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
A.
If both assertion and reason are true and reason is the correct explanation of assertion.
Females having 45 chromosomes (2A + XO) are affected with Turner's syndrome. Individuals having Turner's syndrome have female sexual differentiation but ovaries are rudimentary. Other associated phenotypes of this condition are short stature, webbed-neck, broad chest, lack of secondary sexual characteristics and sterility. Thus, any imbalance in the copies of the sex chromosomes may disrupt the genetic information necessary for normal sexual development.
A tall true breeding garden pea plant is crossed with a dwarf true breeding garden pea plant. When the F1 plants were selfed the resulting genotypes were in ratio of
1:2:1 :: Tall heterozygous: Tall homozygous: Dwarf
3:1:: Tall: Dwarf
3:1:: Dwarf: Tall
3:1:: Dwarf: Tall
Pick out the correct statement.
I. Haemophilia is a sex-linked recessive disease
II. Down's syndrn=me is due to aneuploidy
III. Phenylketonuria is an autosomal recessive gene disorderIv. Sickle cell anaemia is an X-linked recessive gene disorder
II and IV are correct
I, III and IV are correct
I, II and III are correct
I, II and III are correct
In a test cross involving F1 dihybrid flies, more parental-type offspring were produced that the recombinant type offspring. This indicates
chromosomes failed to separate during meiosis
the two genes are linked and present on the same chromosome
both of the characters are controlled by more than one gene
both of the characters are controlled by more than one gene
Match the terms in Column I with their description in Column II and choose the correct option.
| Column I | Column II |
| A. Dominance | 1. Many genes governs a single character |
| B. Codominance | 2. In a heterozygous organism, only one allele expresses itself |
| C. Pleiotropy | 3. In a heterozygous organism both alleles express themselves fully |
| D. Polygenic inheritance | 4. A single gene influences many characters |
| A | B | C | D |
| 2 | 3 | 4 | 1 |
| A | B | C | D |
| 4 | 1 | 2 | 3 |
| A | B | C | D |
| 4 | 3 | 1 | 2 |
| A | B | C | D |
| 4 | 3 | 1 | 2 |
Which of the following most appropriately describes haemophilia?
Chromosomal disorder
Dominant gene disorder
Dominant gene disorder
Which of the following statements is not true for cancer cells in relation to mutations?
Mutations destroy telomerase inhibitor
Mutations inactivate the cell control
Mutations inhibit production of telomerase
Mutations inhibit production of telomerase
Which of the following statements is not true of two genes that show 50% recombination frequency?
the genes may be on different chromosomes
the genes are tightly linked
the genes show independent assortment
the genes show independent assortment
Variation in gene frequencies within populations can occur by chance rather than by natural selection. This is referred to as
genetic flow
genetic drift
random mating
random mating
If two persons with 'AB' blood group marry and have sufficiently a large number of children, these children could be classified as 'A' blood group in 1:2:1 ratio. The modern technique of protein electrophoresis reveals the presence of both 'A' and 'B' type proteins in 'AB' blood group individuals. This is an example of
codominance
incomplete dominance
partial dominance
partial dominance
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