Chapter 27, Problem 4TYK

When Paramecium conjugate:

a. cytoplasmic division produces four daughter cells, eachhaving two micronuclei and two macronuclei.

b. one haploid micronucleus in each cell remains intact; theother three degenerate. The micronucleus of each cell divides once, producing two nuclei, and each cell exchanges one nucleus with the other cell. In each partner the two micronuclei fuse, forming a diploid zygote micronucleus in each cell.

c. the micronucleus of each of the disengaged partners divides meiotically. Macronuclei divide again in each cell, and the original micronucleus breaks down. Each cell has two haploid micronuclei; one of the macronuclei develops into a micronucleus.

d. the mating cells join together at opposite sites of their oral depression.

e. the micronucleus in each cell undergoes mitosis. When mitosis is complete, there are four diploid macronuclei; the micronucleus then breaks down.