11. In a dihybrid cross, the progeny of an Fl individual (hetero2ygous for both characters) will show a phenotypic ratio of

A. 1:1:1:1
B. 1:2:2:1
C. 9:3:3:1
D. 3:1:1:3

12. In an organism, the chromosome number is maintained constant because of

A. independent assortment
B. crossing over
C. DNA duplication
D. synapsis

13. How many chromosomes are there in the budding yeast (S. cerevisiae)?

A. 16
B. 17
C. 18
D. 20

14. Which of the following is correct when a character shows continuous variation assuming a normal distribution?

A. It is governed by many genes with small cumulative effect
B. It is not controlled genetically
C. Many of the variation is due to fluctuation of climate
D. None of the above

15. Raphanobrassica is a classical example of

A. aneuploidy
B. nullisomy
C. allopolyploidy
D. None of the above