Gametogenesis

Question 1

Gametogenesis

Answer 1

process by which haploid or diploid cells give rise to haploid cells
process to obtain gametes via meiosis

Question 2

2 forms of gametogenesis

Answer 2

spermatogenesis and oogenesis

Question 3

end product of meiosis produces a cell with

Answer 3

half the chromosomes as a diploid cell (haploid)

Question 4

Meiosis involves

Answer 4

one round of chromosomal duplication and 2 rounds of nuclear division

Question 5

The human cycle

Answer 5

meiosis
formation of gametes
fertilisation
mitosis
form the new individual

Question 6

spermatogenesis length

Answer 6

70 days

Question 7

spermatogenesis

Answer 7

in the seminiferous tubules
diploid germ cell undergoes mitosis
forms type A and Type B cells
differentiates into primary spermatocytes

Question 8

Primary spermatocyte

Answer 8

undergoes the first
round of meiosis (meiosis I)
forms 2 haploid secondary spermatocytes
these divide meiotically into 4 haploid spermatids by meiosis II

Question 9

Sertoli cells

Answer 9

nurse cells that aid spermatogenesis by providing nourishment
their junctions form the blood-testis barrier

Question 10

Spermatogenesis requires

Answer 10

cooler temperature than the core body temperature thus the testicles hang lower in the male body

Question 11

Sperm produced

Answer 11

when they reach puberty, usually from 10-16 years old
large quantities (~200 million a day) to maximise the likelihood of sperm reaching the egg
continually produce

Question 12

Sperm production occurs in

Answer 12

the testes of the male, seminiferous tubules
tubules are kept separate from the systemic circulation by the blood-testis barrier

Question 13

After formation of the spermatids

Answer 13

cells undergo spermiation where they are released into the lumen of the seminiferous tubules prior to their transport to the epididymis
In the epididymis, sperm is stored and undergoes the final stages of maturation

Question 14

Semen which is produced during male ejaculation contains

Answer 14

sperm and secretions from the prostate, seminal vesicles and bulbourethral glands which aids the sperm cell to overcome the unique environment of the female reproductive tract

Question 15

capacitation occurs

Answer 15

once semen is introduced into the female reproductive tract
allows the sperm to fertilise the egg cell

Question 16

Oogenesis

Answer 16

meiosis leads to the formation of an egg cell (gamete)

Question 17

Oogenesis process

Answer 17

primary oocytes are arrested in prophase I until the female reaches puberty
begins in a developing female embryo
During each month, one oocyte resumes meiosis (ovulation)
secondary oocyte which receives the majority of the cytoplasm and a polar body forms
haploid secondary oocyte initiates meiosis II
this halted at metaphase II until fertilization
if the egg is not fertilized the cell never becomes an ovum and its shed via menstruation
fertilization occurs then meiosis II commences forming an ootid and another polar body
ootid eventually matures into an ovum
Polar bodies form to discard extra sets of chromosomes ensuring the final egg cell is haploid

Question 18

Fertilization

Answer 18

union between the egg and sperm cell nucleus
produces a zygote which is the initial cell of the foetus/baby which eventually divides via mitosis to form an embryo

Question 19

Capacitation

Answer 19

process whereby the membrane over the sperm’s acrosome is weakened due to chemical changes
enzymes are released from the capacitated sperm which then clears a path through the zona pellucida of the egg cell

Question 20

prevent more sperm entry

Answer 20

rapid chemical changes take place across the cell membrane of the oocyte

Question 21

Fusion with sperm allows

Answer 21

maturation of oocyte into an ovum and a polar body

Question 22

The formed zygote has

Answer 22

46 chromosomes, 23 from each parent

Question 23

Infertility

Answer 23

disease of the reproductive system defined by the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse