Explain three modes of reproduction in ciliates.

1. Binary fission: In binary fission, a ciliate cell divides into two identical daughter cells. The cell first replicates its genetic material and then divides into two separate cells. This is the most common mode of reproduction in ciliates and allows for rapid population growth.

2. Conjugation: Conjugation is a sexual process in ciliates where two cells exchange genetic material. During conjugation, two ciliate cells come into close contact and form a temporary bridge called a conjugation bridge. Through this bridge, genetic material is exchanged between the two cells, leading to genetic recombination. This process allows for genetic diversity and adaptation to changing environments.

3. Autogamy: Autogamy is a form of self-fertilization in ciliates where a single cell undergoes a process of nuclear reorganization to produce genetically diverse offspring. During autogamy, the cell's micronucleus undergoes meiosis to produce haploid nuclei, which then fuse to form a new micronucleus. This new micronucleus then undergoes mitosis to produce genetically diverse daughter cells. Autogamy allows for genetic diversity within a population without the need for a partner.