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 

Which of the following statements is not true of two genes that show 50% recombination frequency?
1. The genes are tightly linked
2. The genes show independent assortment
3. If the genes are present on the same chromosome, they undergo more than one crossovers in every meiosis
4.The genes may be on different chromosomes