UNIT 16 Reproduction

Question 1

asexual reproduction

Answer 1

a process
resulting in the production of genetically
identical offspring from one parent

MITOSIS used for asexual repr.

Question 2

in asexual :

Answer 2

• no fusion of gametes so no mixing of genetic info
• produces CLONES
• no genetic variation in offspring

Question 3

the advantages and disadvantages of
asexual reproduction:

a) to a population of a species in the wild
b) to crop production

Answer 3

adv:
- faster
- requires less energy

Question 4

disadv! of asexual

Answer 4

• offspring all genetically identical. reproduction does not produce genetic variation

Question 5

examples

Answer 5

bacteria [asexual]

fungi [both]

small plants [both]

& animals [sexual]

Question 6

sexual reproduction

Answer 6

a process involving the fusion of the nuclei of two gametes to form a zygote and the production of offspring that are genetically different from each other

Question 7

in sexual rep.

Answer 7

gametes formed by MEIOSIS, a type of cell division which produces cells with half the chromosome number

zygote DIVIDES by MITOSIS

Question 8

fertilisation

Answer 8

the fusion of the nuclei of
gametes, combining 23 chromosomes in sperm & 23 in egg resulting in a zygote with 46 chromosomes

Question 9

nuclei of gametes are ____________ and that
the nucleus of a zygote is ____________

Answer 9

nuclei of gametes/GAMETES are HAPLOID and that
the nucleus of a zygote is DIPLOID

[haploid - contain only one set of chromosomes, in humans 23 chromos.
diploid - cell that contains two sets of chromosomes, one from each parent]

Question 10

SEXUAL REPR. - adv:

Answer 10

adv:
- increases genetic variation
- species can adapt to new environments due to variation, giving them a survival advantage
- disease less likely to affect population due to variation

Question 11

disadv:

Answer 11

• takes time and energy to find mates
• difficult for isolated members of the species to reproduce

Question 12

pollination

Answer 12

the transfer of pollen
grains from an anther to a stigma

Question 13

the characteristics of an organism determined by both its environment and genes

asexual reproduction involves one parent and produces genetically identical offspring called clones

sexual reproduction involves two parents and the production of gametes which join together at fertilisation. This mixing of genetic info leads to variations in the offspring

Thee is far more genetic variety in sexual reproduction than in asexual, but sexual repr. is more risky because the organism must find a suitable mate