Animal reproduction Flashcards
What are the three methods of asexual reproduction?
1) Budding 2) Regeneration 3) Parthenogenesis
Describe budding:
New individuals are formed as the outgrowth or buds from the body of older animals
Describe regeneration:
Pieces of organism can regenerate complete individuals
Describe parthenogenesis:
Development of unfertilized eggs.
What is the overall process of sexual reproduction?
Require the joining of two haploid cells (gametes) to form a diploid zygote.
What are the three foundamental steps of sexual reproduction?
1) Gametogenesis 2) Spawning or mating 3) Fertilisation
Describe the three key steps of spermatogenesis:
1) Initial proliferation of male germ cells into spermatogonia proceeds by mitosis. 2) Primary spermatocytes undergo the first meiotic division to form secondary spermatocyte. 3) Second meiotic division produces four haploid spermatids for each primary spermatocyte.
Describe the three key steps of Oogenesis:
1) Oogonia proliferate through mitosis and the resulting primary oocyte immediately enter prophase 1 2) The first meiotic division produces a polar body and a secondary oocyte. 3) The second meiotic division forms an haploid ootid which then idfferentiate into a mature ovum and a second polar body.
What are the 6 events of fertilization?
1) The egg and sperm must chemically recognize each other 2) The sperm is activated, enabling it to gain access to the plasma membrane of the egg. 3) The plasma membrane of the egg fuses with the Plasma membrane of the sperm. 4) The egg blocks entry of additional sperm 5) The egg is metabolically activated and stimulated to start development. 6) The egg and sperm nuclei fuse to create the diploid nucleus of the zygote.
What are the two main kind of fertilization?
1) External fertilization 2) Internal fertilization
What is copulation? (Sohaib has to answer this question, no matter whose turn is)
The physical joining of male and female accessory sex organs.
Describe oviparity:
The animal lays eggs in the environment and their embryos develop outside their mother body.
Describe viviparity:
Animals retain the embryo within the mother’s body.
What are the three major roles of Sertoli’s cells?
-They provide nutrients for the developing sperm. -They form a bloo-testes barrier. -Provide a regulated fluid which allows later stages of development of sperm.
Why are progesterone and estrogen crucial?
-For the maintainance of the uterine lining -They send negative feedback to the anterior pituitary to inhibit gonadotropin release.
