Mode of Reproduction in Animal

• Mode of Reproduction in Animal:

1. Asexual reproduction

• It is a common method among lower animals. It does not involve meiosis nor the gamete formation and fusion.
• The formation of progeny is by a single parent only and does not involve both the sexes, so it is called asexual reproduction.
• The progeny or daughter cells are genetically identical to the single parent and are also referred to as clones.
• The lower animals reproduce asexually by gemmule formation and budding.

Types of Asexual Reproduction in Animals

1. Binary Fission
2. Budding
3. Fragmentation
4. Sporulation
5. Gemmulation
6. Parthenogenesis

2. Sexual reproduction

• It is the process which involves the production of offspring by the formation and fusion of gametes. It is also called amphimixis.
• In animals, gamete formation primarily involves meiosis.
• Sexually reproducing animals shows two main phases in their life time. 

1) Juvenile phase - The earlier juvenile phase mainly represents physical growth phase starting from birth. The animals cannot reproduce sexually in this phase. 

2) Reproductive maturity phase- The later Reproductive maturity phase is attained usually after physical growth is almost over. It involves growth and activity of the sex organs. Animals can reproduce sexually in this phase. 

• Pre-fertilization (gametogenesis and gamete transfer) 

• Fertilization (fusion of male and female gametes)  

• Post fertilization events (formation of zygote and embryogenesis).  

• Seasonal breeders- Goat, sheep, and donkey  

• Continuous breeders- Human and ape