Search results
Results From The WOW.Com Content Network
The biologist Thierry Lodé proposed (2001, 2012) five modes of reproduction based on the relationship between the zygote (fertilised egg) and the parents: [1] [2]. Ovuliparity: fertilisation is external, the oocytes being released into the environment and fertilised outside the body by the male. [1]
Animals, including mammals, produce gametes (sperm and egg) through meiosis in gonads (testicles in males and ovaries in females). Sperm are produced by the process of spermatogenesis and eggs are produced by oogenesis. These processes are outlined in the article gametogenesis.
Asexual reproduction in animals (1 C, 10 P) B. Bird breeding (3 C, 27 P) Birth (5 C, 4 P) Animal breeding (14 C, 46 P) Brood parasites (2 C, 99 P) D. Dinosaur ...
Animal reproduction occurs by two modes of action, including both sexual and asexual reproduction. [1] In asexual reproduction the generation of new organisms does not require the fusion sperm with an egg. [1] However, in sexual reproduction new organisms are formed by the fusion of haploid sperm and eggs resulting in what is known as the ...
The traditional modes of reproduction include oviparity, taken to be the ancestral condition, traditionally where either unfertilised oocytes or fertilised eggs are spawned, and viviparity traditionally including any mechanism where young are born live, or where the development of the young is supported by either parent in or on any part of their body.
[3] [4] [5] In most birds, the cloacal kiss is used, the two animals pressing their cloacas together while transferring sperm. [6] Salamanders , spiders , some insects and some molluscs undertake internal fertilization by transferring a spermatophore , a bundle of sperm, from the male to the female.
Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. There are two forms of reproduction: asexual and sexual. In asexual reproduction, an organism can reproduce without the involvement of another organism.
Sexual reproduction is the most common life cycle in multicellular eukaryotes, such as animals, fungi and plants. [6] [7] Sexual reproduction also occurs in some unicellular eukaryotes. [2] [8] Sexual reproduction does not occur in prokaryotes, unicellular organisms without cell nuclei, such as bacteria and archaea.