Animal Reproduction

• Asexual Reproduction is a creation of new individuals whose genes all come from one parent without the fusion of egg and sperm
• Fission is the separation of a parent into two or more individuals of approximately equal size
• Budding is a type of mechanisms of asexual reproduction in which new individuals arise from outgrowths of existing ones; the offspring may either.
• Fragmentation is the breaking of the body into several pieces, some or all of which develop into complete adults.
• Regeneration - the regrowth of lost body parts; usually accompanied with fragmentation.
• Sexual Reproduction - creation of offspring by the fusion of haploid gametes to form a zygote (fertilized egg), which is diploid. Relatively slow.
• Female gamete: the unfertilized egg (also called an ovum), is a relatively large cell and not motile.
• Male gamete: the sperm, is generally a much smaller, motile cell
• Internal Fertilization - the fusion of sperm and egg, may take place inside the body. The male generally delivers sperm cells directly into the body of the female. Her moist tissues provide the watery medium required for movement of sperm.
• External Fertilization - Mating partners usually release eggs and sperms into the water simultaneously
• Metagenesis - also known as ‘transformation development’, refers to an alternation of asexual and sexual generations
• Parthenogenesis - also known as ‘virgin development’, is a form of reproduction in which an unfertilized egg develops into an adult animal.
• Hermaphroditism - means that a single organism produces both eggs and sperm.
• Gonadotropin - releasing hormone (GnRH) stimulates the release of two hormones