Persons suffering from sickle-cell anaemia normally do not suffer from

• cholera

• malaria

• high blood pressure

• hepatitis

Which one of the following information is essential to, determine the genetic map distance between two genes located on the same chromosome?

• Length of the particular chromosome

• Number of genes present in the particular chromosome

• Number of nucleotides in the particular chromosome

• Percentage of crossing over or recombinant frequency between the two genes

Which one of the following statements is relevant to sex linked characters?

• They always follow criss-cross inheritance

• They do not follow criss-cross inheritance

• They are mostly present on Y-chromosome

• They are only present on X-chromosome

A male rabbit of genotype 'AABBDDEE' is crossed with a female rabbit of genotype 'aabbddee' to produce F₁ hybrid offspring. How many genetically different gametes can be produced by this F₁ hybrid?

• 4

• 8

• 16

• 32

Match the items in column I with those in column II and choose the correct answer.

Column I	Column II
A. Klinefelter syndrome	1. Mutation in autosomal gene
B. Thalassaemia	2. Mutation in sex chromosome linked gene
C. Down syndrome	3. Trisomy of autosome
D. Colour blindness	4. Trisomy of sex chromosme

• A- 1; B- 2; C- 3; D- 4

• A- 2; B- 3; C- 4; D- 1

• A- 3; B- 4; C- 1; D- 2

• A- 4; B- 1; C- 3; D- 2

Choose the correct statements regarding genetic disorders.

I. Turner's female is result of aneuploidy.

II. Tritanopia is a sex-linked recessive disorder.

III. Haemophilia-C follows criss-cross pattern of inheritance.

IV. Sickel cell anaemia is due to mutation of alleles in chromosome 11.

• I, IV

• II, III

• I, III

• II, III

357.

The type of mutation in the nucleotide sequence given below is

• Transition

• Transversion

• Deletion

• Inversion

Marfan syndrome, a dominant single gene defect is characterised by lens dislocation, long limbs, spindly fingers, caved in chest and weakened aorta. This is an example of

• Complete dominance

• Epistasis

• Pleiotropy

• Codominance

Study the following statements.

I. F₁ -progeny is the first hybrid generation and progeny resembles either of the two
parents.

II. F₂ progeny is a resultant hybrid generation of cross pollination among F₁ progeny and progeny shows retain as such both drawf and tall plants.

III. F₂ progeny is second hybrid generation, produced by selfing F₁ hybrids and progeny contained both drawf and tall plants.

IV. The proportion of probability of plants that were drawf were 1/4th of the F₂ plants while 3/4th of the F₂ plants were tall.

The correct statements are

• I, II, III, IV

• I, III, IV

• I, II, IV

• III, IV

In sweet pea, C and P genes are essential for flower colour. In absence of either or both the genes, the flowers are white. What will be the percentage of coloured flowers in the offspring of cross Ccpp x ccPp?

• 75%

• 25%

• 80%

• 50%