reproduction and inheritance

Question 1

what is the role of oestrogen in the menstrual cycle?

Answer 1

TARGET ORGAN/TISSUE: 1&2. pituitary gland 3. uterus lining

1. as oestrogen levels rise, they stop FSH production (stops another ovum being matured)
2. trigger LH production in the pituitary gland
3. repairs the lining of the uterus after menstruations & thickens it

Question 2

function of the penis?

Answer 2

• transports urine & semen out of body
• contains tissue which fills w blood to become erect (erectile tissue) which helps to pass semen out of body & into females vagina during sexual intercourse

Question 3

function of the sperm duct?

Answer 3

maturing sperm are transported along this tube

Question 4

function of the testes?

Answer 4

• where sperm cells are formed by meiosis
• produces hormone testosterone

Question 5

function of the seminal vesicle and prostate gland?

Answer 5

• release liquids into sperm duct, which mixes w sperm cells to form semen
• the liquid provides nutrients to the sperm

Question 6

function of the urethra (males)?

Answer 6

tube inside penis which can transport either urine or semen

Question 7

function of the ovaries?

Answer 7

• where egg cells are formed by meiosis (in the follicle)
• produces hormones oestrogen & progesterone

Question 8

function of the oviducts/fallopian tubes?

Answer 8

• egg cells travel down this to the uterus
• lined w cilia which move the cell
• site of fertilisation

Question 9

function of the uterus?

Answer 9

• a lining forms in the uterus, where the embryo will implant
• the foetus develops in the uterus, which has a thick muscular wall
• this contracts during labour

Question 10

function of the cervix?

Answer 10

narrow opening to the uterus, this dilates during labour, to allow the baby to be born

Question 11

function of the vagina?

Answer 11

• muscular tube that leads from cervix to outside of woman’s body
• a man’s penis goes into it during sexual intercourse, and the baby passes through it when it’s born

Question 12

what’s the placenta?

Answer 12

an organ in the uterus of pregnant mammals that allows transfer of nutrients & waste products between mother and fetus through umbilical cord

Question 13

what’s the function of the placenta?

Answer 13

• anchors embryo in uterus
• allows nutrients (i.e. glucose, amino acids, salts) and oxygen to move from mother —> embryo
• allows metabolic wastes - co2 & urea - to move from embryo —> mother

these materials pass from one to the other by diffusion

• also secrets progesterone to ensure uterus lining remains thick, & to prevent baby from aborting

Question 14

what’s amniotic fluid?

Answer 14

• during pregnancy a membrane called the amnion encloses developing embryo
• amnion secretes a fluid called amniotic fluid
• seems like it’s basically just water lol

Question 15

what is amniotic fluids role during pregnancy?

Answer 15

protects developing embryo against:
- mechanical shocks (jolts & bumps)
- drying out
- temperature fluctuations (due to waters high specific heat capacity)

Question 16

what hormone causes the development of secondary sexual characteristics?

Answer 16

main one is testosterone for males, main one is oestrogen for females

Question 17

what are the secondary sexual characteristics for males?

Answer 17

• voice breaks
• sperm production begins
• shoulders broaden
• facial, armpit, body and pubic hair growth
• greater muscle development
• growth & development of genitalia
• possible mood swings and acne

Question 18

what are the secondary sexual characteristics for females?

Answer 18

• voice deepens (but doesn’t break)
• menstrual cycle begins
• pelvis broadens in preparation for pregnancy & labour
• armpit & pubic hair growth
• muscle development & fat deposits on breasts, hips, thighs
• growth & development of genitalia
• possible mood swings and acne

Question 19

what’s the role of progesterone in the menstrual cycle?

Answer 19

TARGET ORGAN/TISSUE: 1: pituitary gland 2: uterus lining

1. FSH and LH inhibited (stops further ovum being matured & released)
2. thickness of uterine lining maintained

Question 20

what’s the role of FSH in the menstrual cycle?

Answer 20

TARGET ORGAN/TISSUE: follicle in ovary

• follicle develops & ovum matures (not released yet)
• maturing follicle releases oestrogen

Question 21

what’s the role of LH in the menstrual cycle?

Answer 21

TARGET ORGAN/TISSUE: follicle in ovary

• ovulation - follicle on ovary releases mature ovum into oviduct
• remnant of follicle (on ovary) becomes corpus luteum

Question 22

what gland is FSH secreted from?

Answer 22

pituitary gland

Question 23

what gland is oestrogen secreted from?

Answer 23

ovary (follicle in the ovary)

Question 24

what gland is LH secreted from?

Answer 24

pituitary gland

Question 25

what gland is progesterone secreted from

Answer 25

ovary (corpus luteum)