Principles of Inheritance and Variation

When dominant and recessive alleles express themselves together it is called

1. Dominance
2. Pseudo dominance
3. Co-dominance
4. Amphidominance

Ratio of complementary genes is

1. 9 : 3 : 4
2. 9 : 7
3. 12 : 3 : 1
4. 9 : 3 : 3 : 4

Independent assortment of genes does not take place when

1. Genes are located on non-homologous chromosomes
2. Genes are linked and located on same chromosome
3. Genes are located on homologous chromosomes
4. All the above

Sickle cell anaemia is due to

1. Change of amino acid in either or chain of haemoglobin
2. Change of amino acid in chain of haemoglobin
3. Change of amino acid in both and chain of haemoglobin
4. Change of amino acid in chain of haemoglobin

Number of Barr bodies in XXXX female is

1. 3
2. 1
3. 2
4. 4

Male XX and female XY sometime occur due to

1. Aneuploidy
2. Deletion
3. Transfer of segments in X and Y chromosomes
4. Hormonal imbalance

Probability of four sons to a couple is : -

1. 116
2. 18
3. 14
4. 132

Due to the cross between TTRr × ttrr the resultant progenies showed how many percent plants tall, red flowered:

1. 50%
2. 100%
3. 75%
4. 25%

According to mendelism which character is showing dominance?

1. Green colour in seed coat
2. Wrinkled seed
3. Terminal position of flower
4. Green pod colour

Mongolian idiots are due to trisomy in 21st chromosome is called:

1. Klinefelter's syndrome
2. Down's syndrome
3. Turner's syndrome
4. Triplex syndrome