In sickle cell anemia, the sequence of amino acids from the first to the seventh position of the b-chain of haemoglobin S(HbS) is

• His, Leu, Thr, Pro, Glu, Val, Val

• Val, His, Leu, Thr, Pro, Glu, Glu

• Thr, His, Pro, Val, Pro, Val, Glu

• Glu, His, Leu, Pro, Val, Glu, Glu

• Glu, His, Leu, Pro, Val, Glu, Glu

$\frac{1}{4}$ TT : $\frac{1}{2}$ Tt : $\frac{1}{4}$ tt is the binomial expansion of

• ${\left(\frac{1}{2} \mathrm{T} + \frac{1}{2} \mathrm{t}\right)}^2$

• ${\left(\frac{1}{4} \mathrm{T} + \frac{1}{4} \mathrm{t}\right)}^2$

• ${\left(\frac{1}{4} \mathrm{T} + \frac{1}{2} \mathrm{t}\right)}^2$

• ${\left(\frac{1}{2} \mathrm{T} + \frac{1}{4} \mathrm{t}\right)}^2$

• ${\left(\frac{1}{2} \mathrm{T} + \frac{1}{4} \mathrm{t}\right)}^2$

An example for codominance

• Eye colour in Drosophila

• Seed shape and colour in pea plants

• ABO blood group in man

• Haemophilia in man

• Haemophilia in man

The disorder caused by point mutation is

• Down's syndrome

• Sickle cell anemia

• Klinefelter's syndrome

• Tetany

• Tetany

Two pink flowered snapdragon plants(Rr) are self-pollinated. The probability of the off springs to have white flowers are

• 25%

• 50%

• 75%

• 2.5%

• 2.5%

When mendel self-hybridised the F₁ plants of genotype RrYy, in the F₂ generation they yellow and green colour segregated in the ratio

• 1 : 2 : 1

• 3 : 1

• 9 : 3 : 3 : 1

• 1 : 1

• 1 : 1

Which of the following disorder is caused by autosomal aneuploidy?

• Down's syndrome

• Haemophilia

• Sickle cell anemia

• Phenylketonuria

• Phenylketonuria

418.

Identify the scientists from the hints given below

1. They used chromosome movement to explain Mendel's lay
2. They noted that the behaviour of chromosome was parallel to the behaviour of genes.

• Morgan and Correns

• De Vries and Boveri

• Brides and Correns

• Bridges and Sutton

• Bridges and Sutton

How many different types of gametes are produced, if the genotype of a plant is AABB?

• 8

• 6

• 4

• 2

• 2

Which among these are correctly matched

(i) Down's syndrome - trisomy 21
(ii) Klinefelter's syndrome - 45, XO
(iii) Turner's syndrome -  47x XXY

• (ii) and (iii) only

• (i) only

• (i) and (ii) only

• (iii) only

• (iii) only