sexual v asexual & mitosis v meiosis

Question 1

list 3 advantages of sexual reproduction

Answer 1

• produces variation in the offspring due to a mixture of two sets of chromosomes
• if the environment changes variation gives a survival advantage by natural selection and evolution
• natural selection can be speeded up by humans in selective breeding to increase food production

Question 2

list 4 advantages of asexual reproduction

Answer 2

• only one parent needed
• more time and energy efficient as do not need to find a mate
• process is faster than sexual reproduction
• many identical offspring can be produced when conditions are favourable

Question 3

list 3 organisms that reproduce both sexually and asexually

Answer 3

• Malarial parasites reproduce asexually in the human host, but sexually in the mosquito
• Many fungi reproduce asexually by spores but also reproduce sexually to give variation.
• Many plants produce seeds sexually, but also reproduce asexually by runners such as strawberry plants, or bulb division such as daffodils

Question 4

haploid

Answer 4

single chromosome

Question 5

diploid

Answer 5

pairs of chromosomes

Question 6

cons asexual

Answer 6

• no genetic variation as all offspring clones
• means if a disease comes along, could wipe out whole population if all susceptible
• less chance of adapting to new conditions e.g climate / predator

Question 7

cons sexual

Answer 7

• more time and energy than asexual
• need to impress mate