Arrange the following in correct sequence with reference to sexual reproduction in Rhizopus
(I) Formation of germ tube
(II) Formation of zygophores
(III) Formation of warty wall layer of zygospore
(IV) Secretion of trisporic acid
The correct sequence is

Options

A. IV, III, II, I
B. IV, II, III, I
C. II, I, IV, III
D. I, III, II, IV

Answer

B

Explanation

Sexual Reproduction in Rhizopus is by conjugation Hyphae belonging to different strains come in close contact with one another. Tip of the hyphae are separated by septa from the rest of the hyphae. Each tip contains many nuclei with cytoplasm, mitochondria and food material. The two tips are called gametangia.
The walls of the gametangia that are in contact dissolve away allowing the two protoplasts to fuse. The zygote resulting from this fusion develops into a zygospore. Zygospore has a thick wall and is quick resistant to unfavourable conditions. The zygospore will later germinate and form germ tube.