Gametogenesis

Question 1

what is gametogenesis and discuss describe the 2 types

Answer 1

maturation of gametes:
spermatogenesis - formation of spermatozoa (formation of sperm)
oogenesis (formation of ova/egg)

Question 2

what happens in spermatogenesis and where does it occur

Answer 2

sperm matures as tails form in the seminiferous tubules in each testi

Question 3

what are the 4 steps of the spermatogenesis cycle

Answer 3

1. GROWTH: from puberty some spermatogonia daughter cells undergo growth
2. primary spermatocytes undergo meiosis I
3. Secondary spermatocytes undergo meisosi II to produce 2 spermatids (haploid)
4. mATURATION: Spermatids mature

Question 4

describe the structure of a sperm (using diagram)

Answer 4

about 0.06mm long
acrosome containes enzyme
head contains genetic material
middle contains mitochondria
little cytoplasm and receives nourishment from semen

Question 5

describe oogenesis before birth (in females ovaries)

Answer 5

millions oogonia develop in ovaries of unborn girl, they grow.
primary oocytes begin prophase 1 of meiosis surrounded by one layer of cells

Question 6

what happens during puberty (oogenesis)

Answer 6

follicles complete meiosis I and produce 2 cells on unequal size

Question 7

what are the two types of cells oogenesis produces after puberty

Answer 7

1. secondary oocyte (half number of chromosomes and majority of original cytoplasm)
2. first polar body (half number of chromosomes and very little original cytoplasm)

Question 8

what happens during ovulation

Answer 8

the cytoplasm follicle ruptures releasing the secondary oocyte and primary polar body into uterine tube.

Question 9

how does fertilisation occur

Answer 9

the secondary oocyte starts meiosis II but stops at metphase, if the oocyte is fertalised meiosis II will complete producing 2 cells of unequal size (one and ovum and the other make secondary polar bodies which all disintegrate