What is the number of linkage groups in humans?

1. 22
2. 23
3. 24
4. 46

Abnormal chromosomes are frequent in malignant tumors. Errors such as translocations may place in gene in close proximity to different control regions. Which of the following might then occur to make the cancer worse ?

1. An increase in non-disjunction

2. Expression of inappropriate gene products 

3. A decrease in mitotic frequency 

4. Death of the cancer cells in the tumor 

R and Y genes of Maize lie very close to each other. When RRYY and rryy genotype are hybridised, F2 generation will show
1. Segregation in 9: 3 : 3 : 1 ratio
2. Segregation is 3 : 1 ratio
3. Higher number of parental types
4. Higher number of recombinant types

The results of a dihybrid cross deviate significantly from the expected 9:3:3:1 ratio. This is because
1. Your plant was faulty
2. The plant can only be self- pollinated in nature
3. You picked two genes that are linked and thus do not assort independently.
4. The genes involved show blending inheritance.

When a cluster of genes shows linkage behaviour they:

1. Do not show a chromosome map

2. Show recombination during meiosis

3. Do not show independent assortment

4. Induce cell division

Two genes are linked. The frequency of recombinants formed between the two loci will be:
1. different between males and females.
2. determined by their relative dominance.
3. the same as if they were not linked.
4. proportional to the distance between them.