PRINCIPLES OF INHERITANCE AND VARIATION
2016 MARCH
Colour blindness, Down’s syndrome, Haemophilia, Thalassemia (Score: 1)
2. Study the following cross and answer the questions. [Hint: ABO blood group in man is controlled by three alleles IA, IB and i]
Father (Blood group A) x Mother (Blood group B)
Son (Blood group O)
a. Write the genotypes of father, mother and son.
b. The type of dominance of human blood group inheritance is ------------ (Scores: 2)
3. Observe the figures and answer the questions.
a. Identify the syndrome A and B.
b. What are the chromosome numbers in A & B? (2)
2016 SAY
1. a) Complete the flowchart of chromosomal disorders by filling the blank boxes (A and B). (Scores 2)
b) What is aneuploidy? (Score 1)
2. Observe the figure below and answer the following questions:
a. Identify the figure.
b. What shows the shaded symbols? (Scores 2)
MARCH 2017
1. The following table shows the F, generation of a dihybrid cross. Identify the ‘Phenotype’ with homozygous recessive genotype. Find out A : B : C : D. (Scores: 2)
No.
|
Phenotype
|
No. of offspring (F2 gen.)
|
1
|
A
|
21
|
2
|
B
|
7
|
3
|
C
|
63
|
4
|
D
|
21
|
2. Which of the following do not have similar sex chromosomes? (Homogametic)
(1) Human female (2) Drosophila female
(3) Bird female (4) Bird male (Score: 1)
3. Examine the following fragment of beta globin chain in human haemoglobin and identify the hereditary disease with reason. (Scores: 2)
MARCH 2018
1. ln a classroom discussion, a student said that the sex of the baby is determined by father. Analyse the statement and give reason for it.
2. Observe the given cross.
a. Name the phenomenon.
b. Write down the theoretically given explanations of the phenomenon.
3. Hemophilia, Sickle cell anemia and Phenyl Ketonuria are Mendelian disorders.
a. What do you mean by Mendelian disorder?
b. Which one of the above is an example of inborn error of metabolism? Mention the cause of the disorder.