4.2 - Sexual Reproduction in Plants

Question 1

What is the aleurone layer?

Answer 1

The protein-rich outermost layer of the endosperm that serves as an important enzyme store

Question 2

What is the anther?

Answer 2

The pollen-bearing structure of the stamen

Question 3

Define what a carpel is

Answer 3

The female part of the plant consisting of a stigma, a style and an ovary

Question 4

What are cotyledons?

Answer 4

Embryonic seed leaves that emerge following germination

Question 5

Explain what cross-pollination is

Answer 5

A type of pollination in which pollen is transferred from an anther of one plant to a stigma of a different plant. This results in plants with greater genetic diversity.

Question 6

Define dehiscence

Answer 6

The splitting of an anther resulting in the release of pollen grains

Question 7

What are dicotyledons?

Answer 7

Plants that produce seeds that contain two cotyledons; they have two primary leaves

Question 8

What is double fertilisation?

Answer 8

Fertilisation of seed plants in which one male gamete fuses with a female gamete to form a diploid zygote and another fuses with two polar nuclei to form a triploid endosperm nucleus

Question 9

Define what endosperm is

Answer 9

The food source surrounding the plant embryo

Question 10

Explain what an endospermic seed is

Answer 10

A seed that contains an endosperm when mature e.g maize

Question 11

What is germination?

Answer 11

The process by which a plant grows from a seed

Question 12

What is gibberellin?

Answer 12

A plant hormone, which during germination, induces the synthesis of amylase by aleurone cells, hydrolysing stored nutrients in the endosperm

Question 13

Explain what a hilum is

Answer 13

A scar on the testa as a result of separation from its funicle

Question 14

What is an insect-pollinated flower?

Answer 14

A type of flower that relies on insects to transfer pollen grains between flowers

Question 15

What is a micropyle?

Answer 15

A pore in the integument of an ovule through which the pollen tube enters the embryo sac. It remains as a pore in the testa.

Question 16

Explain what a non-endospermic seed is

Answer 16

A seed that does not contain endosperm when mature e.g broad bean. Cotyledons serve as a food source.

Question 17

Define the ovary of a plant

Answer 17

Part of the carpel that hold the ovules and following fertilisation, develops into the fruit

Question 18

What is an ovule of a plant

Answer 18

The part of the ovary that gives rise to and contains the female germ cell. After fertilisation, the ovule becomes the seed

Question 19

Define what petals are

Answer 19

Structures that surround the reproductive parts of a flower. They are often brightly coloured and fragrant to attract insects

Question 20

What is a plumule?

Answer 20

The part of a plant embryo that develops into the primary shoot

Question 21

What is a pollen grain?

Answer 21

A single granule of pollen that contains the male haploid gamete. Grains are small and produced in large numbers in wind-pollinated plants, whereas they are large and sticky in insect-pollinated plants

Question 22

What is a pollen tube?

Answer 22

A hollow tube that grows from a pollen grain to the embryo sac in the ovule after pollination. It delivers two male gametes

Question 23

Define what pollination is

Answer 23

The deposition of pollen onto a stigma from an anther

Question 24

What is the radicle?

Answer 24

The part of a plant embryo that develops into the root

Question 25

Explain what self-pollination is

Answer 25

A type of pollination in which pollen is transferred from an anther of a plant to a stigma of the same plant. This results in plants with less genetic diversity

Question 26

What is the stamen?

Answer 26

The male part of the plant consisting of an anther and a filament that is involved in the production of male gametes in the form of pollen grains

Question 27

Define what the stigma is

Answer 27

The sticky structure of the carpel that receives pollen grains

Question 28

Explain what the tapetum is

Answer 28

A specialised layer of cells within the anther that provide nutrients to developing pollen grains

Question 29

What is the testa?

Answer 29

The outer covering of a seed, commonly referred to as the seed coat

Question 30

What is a wind-pollinated flower?

Answer 30

A type of flower that relies on wind to transfer pollen grains between flowers