REPRODUCTION in PLANTS and HUMANS

FLASHCARDS

Define the term asexual reproduction.

Asexual reproduction is the reproductive process that results in genetically identical offspring from one parent.

What are some examples of asexual reproduction in living organisms?

Examples of asexual reproduction in living organisms include:

binary fission in bacteria

plants reproducing via bulbs, tubers or runners

budding in yeast cells

budding in jellyfish

parthenogenesis in aphids

What are the advantages of asexual reproduction for wild populations and crop production? (Extended Tier Only)

Asexual reproduction can be advantageous because it produces offspring that are genetically identical to their parents, meaning that:

characteristics that are well suited to the current environment of a wild population are preserved

desirable characteristics of cultivated crop varieties are preserved

In addition to this, asexual reproduction only requires one parent so energy does not need to be expended to find a mate.

What are the disadvantages of asexual reproduction for wild populations and crop production? (Extended Tier Only)

Asexual reproduction can be disadvantageous because offspring lack genetic variation, meaning that:

wild populations are less able to adapt to environmental change

crop varieties will all be susceptible to the same pests and diseases

Define the term sexual reproduction.

Sexual reproduction is the reproductive process during which the nuclei of two gametes fuse to form a zygote and genetically different offspring are produced.

Define the term fertilisation.

Fertilisation is the fusion of gamete nuclei.

What does it mean when gametes are described as haploid? (Extended Tier Only)

Gametes are haploid, meaning that they contain half the full number of chromosomes.

True or False?

Zygotes are diploid. (Extended Tier Only)

True.

Zygotes form when two haploid gametes fuse, producing a diploid zygote with the full number of chromosomes.

What are the advantages of sexual reproduction for wild populations and crop production? (Extended Tier Only)

Sexual reproduction can be advantageous because it generates genetic variation; this means that:

wild populations can adapt to changes in their environment

crop plants may not all be equally susceptible to pests and disease

What are the disadvantages of sexual reproduction for wild populations and crop production? (Extended Tier Only)

Sexual reproduction can be disadvantageous because offspring are different to their parents, meaning that:

some of the offspring in a wild population may be less well suited to their environment than their parents

the desirable traits of a crop may not be present in offspring grown from seed

What are the structures labelled A-D in the diagram?

Diagram of a flower labelled with parts A (location of pollen production), B (the tube that supports the female part of the flower), C (the point where pollen lands during pollination), and D (the location of fertilisation).

Structures A-D are:

A = anther

B = style

C = stigma

D = ovary

Diagram of a flower labelled with parts A (location of pollen production), B (the tube that supports the female part of the flower), C (the point where pollen lands during pollination), and D (the location of fertilisation).

True or False?

Petals of insect-pollinated flowers tend to be brightly coloured.

True.

Petals of insect-pollinated flowers tend to be brightly coloured to attract pollinator insects.

What is the role of the anthers in flowers?

Anthers produce and release pollen.

What are the structures labelled X and Y in the diagram?