Asexual reproduction:

1. It does not involve formation and fusion of gametes.

2. It is uniparental.

3. Reproductive units are somatic cells of parent.

4. It involves only mitotic divisions.

5. Offspring are genetically similar to parents.

6. Fast and simple process.

Sexual reproduction:

1. It involves formation and fusion of gametes.

2. It is generally biparental.

3. Reproductive units are germ cells of parent.

4. It involves meiosis during gamete formation.

5. Offspring are genetically different from parents.

6. Slow, elaborate and complex process.

The types of asexual reproduction exhibited by unicellular organisms:

• Many single-celled organisms reproduce by binary fission (e.g., Amoeba, Paramecium), where a cell divides into two halves and each rapidly grows into an adult. 
• In yeast, the division is unequal and small buds are produced that remain attached initially to the parent cell which eventually gets separated and mature into new yeast organism (cells).