2.4.4 - Gametogenesis Flashcards
What is the first stage in spermatogenesis.
Primordial germ cells divides by mitosis to form a spermatogonia.
What do spermatogonia do?
Grow into primary spermatocytes.
What do primary spermatocytes do?
Divide by meiosis to form 2 haploid secondary spermatocytes.
What do secondary spermatocytes do?
Divide by meiosis again to form 4 haploid spermatids.
What do spermatids do?
Differentiate into spermatozoa.
What is a structural difference between a spermatid and a fully matured spermatazoa.
Spermatids have no acrosome or flagellum.
What does the flagellum of a sperm cell contain and what do they do?
Microtubules - Produce whip-like movements to help the sperm swim towards the ovum.
What is the first stage of oogenesis?
A primordial germ cell divides by mitosis to form oogonium.
What does an oogonium do?
Grows to form a primary oocyte.
What does a primary oocyte do?
Divides by meiosis to form a haploid secondary oocyte and the first polar body.
What needs to happen before a secondary oocyte can undergo the second mitotic division?
Fertilisation.
What is formed when the secondary oocyte divides by meiosis?
The ovum and a second polar body.
What happens to the polar bodies that are formed?
They disintegrate.
What is the sorophyte generation in plant gametogenesis?
Diploid and produces spores by meiosis.
What is the ganetophte generation in plant gametogenesis?
Haploid and produces gametes by mitosis.
Where do pollen grains develop?
Pollen sacs.
