Reproduction

Question 1

Describe sexual reproduction

Answer 1

• involved fusion of male and female gametes
  = mixing of genetic information

Question 2

Describe asexual reproduction

Answer 2

Asexual
- only one parent
- no gametes
- offspring gametes
- only involves mitosis

Question 3

Describe meiosis stages

Answer 3

• only in reproductive organs
• chromosomes copied
• cell divides in 2
• both cells divide again
• halved chromosomes
• different offspring
• produces gametes

Question 4

Adv of sexual reproduction (plants)

Answer 4

• offspring have variation
  = better adapted to survive and colonise new areas by seed dispersal
  = make many offspring

Question 5

Adv of asexual reproduction

Answer 5

• only one parent needed
  = more efficient in both time and energy
  = faster
• useful when conditions are favourable
  = allows organism to produce many genetically identical offspring quickly
• more energy efficient
• less time

Question 6

Disadvantage of asexual reproduction

Answer 6

• very risky
  = as all offspring are identical they could all die if conditions become unfavourable

Question 7

Examples of different reproduction

Answer 7

• inside mosquito malaria parasite uses sexual reproduction
• fungi use asexual reproduction or asexually to produce variation
• flowers do it sexually to produce seeds

Question 8

What’s a mutation

Answer 8

A change to a base

Question 9

Testes function

Answer 9

Produce testosterone
= produce sperm

Question 10

Ovaries function

Answer 10

Produce oestrogen
= eggs in ovaries start to mature

Question 11

Describe preparation for menstruation

Answer 11

• uterus lining becomes thick and spongy

Question 12

Describe what happens in the menstrual cycle 

Answer 12

• egg makes way to uterus
• if sperm present egg can be fertilised
• if this happens it can implant into uterus wall and develop into a baby

Question 13

What happens if egg isn’t fertilised

Answer 13

• the egg and uterus lining are released
  = called a period

Question 14

Function of oestrogen and progesterone

Answer 14

• maintain the uterus lining incase the egg is fertilised and implants

Question 15

Describe what happens to hormones during the menstrual cycle

Answer 15

• fsh released by pituitary gland
• fsh travels in blood to ovaries where it causes egg to mature
• at same time fsh triggers ovaries to make oestrogen (causes lining of uterus to thicken)
• oestrogen stops pituitary gland releasing more FSH
• pituitary gland releases LH
• LH triggers mature egg to be released
• when egg released progesterone released
• progesterone stops pituitary gland releasing FSH and LH
  = prevent more eggs from maturing
• progesterone keeps lining of uterus thick

Question 16

Progesterone function

Answer 16

• stops pituitary gland from releasing fsh and lh
  = prevent more eggs being matured or released
• keeps lining of uterus thick incase fertilised egg is implanted

Question 17

How does FSH, oestrogen, progesterone and LH control menstrual cycle

Answer 17

• FSH stimulates egg to mature
• LH stimulates egg to be released
• oestrogen and progesterone maintain uterus lining
• oestrogen inhibits FSH production
• progesterone inhibits FSH and LH production