16. The proteins that form the walls of the microtubules are

A. actin
B. tubulin
C. pectin
D. hydroxyproline

17. The color of the flower is due to the presence of

A. chlorophyll
B. xanthophylls
C. florigen
D. chromoplast or anthocyanin

18. What are the names of the two genders of haploid yeast cells?

A. A and Alpha
B. M and F
C. Y(a)and Y(b)
D. None of these

19. Neurospora is used as an experimental tool in

A. ecology
B. cytology
C. genetics
D. physiology

20. The volume of O₂ liberated in photosynthesis has which of the following ratio to Co₂?

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