Plant Reproduction

Question 1

What are the two types of plant reproduction?

Answer 1

Sexual and asexual reproduction

Question 2

Define ‘sexual reproduction’

Answer 2

When two ‘parents’ create a genetically varied offspring using specialised sex cells called gametes

Question 3

Where is sexual reproduction advantageous?

Answer 3

In a changing environment

Where there is a threat of disease from pathogens

Question 4

What are the threee steps of sexual reproduction?

Answer 4

1. Pollination
2. Fertilisation
3. Germination

Question 5

Define ‘asexual reproduction’

Answer 5

When one ‘parent’ creates a genetically identical offspring (clones), without the use of gametes

Question 6

Where is asexual reproduction advantageous?

Answer 6

In a stable environment, so clones/offspring can aquire any adaptations the ‘parent’ had

Question 7

How is asexual reproduction carried out by ‘runners’?

Answer 7

A runner leads off of the ‘parent’ plant and grows a clone where the runner touches the ground

Question 8

How is asexual reproduction carried out by ‘tubers’?

Answer 8

One plant can produce many tubers, which are swollen underground stems containing lots of food, which each producing many shoots creating the new plant

Question 9

How is asexual reproduction carried out by ‘bulbs’?

Answer 9

Underground bulbs with thick leaves contain stored food, which grow a main shoot, and sometimes one out the side creatig a ‘daughter’ bulbs, so two plants are fromed

Question 10

How is asexual reproduction carried out by ‘cuttings’?

Answer 10

A piece of the plant’s stem, with a few attached leaves, is cut and planted in damp compost, where it will grow roots, and develop into a new plant. This is an artificial method of asexual reproduction

Question 11

What are the three main functions of the plant’s flowers?

Answer 11

1. Production of gametes
2. Sites of pollination and fertilisation
3. Sites of seed and fruit formation

Question 12

Which gamete is produced by the male part of the flower, and where is it produced?

Answer 12

Pollen - produced in the anther

Question 13

Which gamete is produced by the female part of the flower, and where is it produced?

Answer 13

Ova - produced in the ovules

Question 14

What is the name of the male and female parts of the flower?

Answer 14

Male - stamen

Female - carpel

Question 15

Define ‘cross-pollination’ and ‘self-pollination’

Answer 15

Cross-pollination: the transfer of pollen from the anther of one flower to the stigma of another flower on a different plant

Self-pollination: when the pollen does not reach a different plant, and the pollen from the anther fertilises the stigma of the same plant

Question 16

Label the structure of this flower:

Answer 16

Question 17

How is the stamen of a flower adapted for insect or wind pollination?

Answer 17

Insect: enclosed within the flower

Wind: exposed outside of the petal

Question 18

How is the stigma of a flower adapted for insect or wind pollination?

Answer 18

Insect: enclosed within the flower, and sticky

Wind: exposed outside of the petal, often feathery

Question 19

How are the petalsof a flower adapted for insect or wind pollination?

Answer 19

Insect: small, usually green

Wind: large and brightly coloured

Question 20

Describe ‘fertilisation’

Answer 20

1. The pollen lands on the stigma, and a pollen tube grows down through the style
2. Enzymes are secreted by the tip of the pollen tube which digest the tissue of the style
3. The male gamete travels to the ovule through the pollen tube
4. The tube delivers the male gametes to an ovule, where the gamete enters through a small hole, the micropyle
5. The male gamete then fuse with the female gamete

Question 21

Describe how fruits are formed from a zygote

Answer 21

• Zygote: male and female gamete fused (fertilisation)*
  1. The zygote develops into an embryonic plant with a small root (radicle) and a shoot (plumule)
  2. The other contents of the ovule develop into a food store for the young plant when it germinates
  3. The ovule wall becomes the seed coat (the hard coating of the seed)
  4. The ovary wall becomes the fruit coat

Question 22

What three things are required for germination?

Answer 22

Warmth - optimum temperature for enzymes

Oxygen - to aerobically respire

Water - to activate the enzymes

Question 23

How does a germinating plant get fuel/food before it’s in a position to respire?

Answer 23

It uses enzymes to break down the carbohydrates in it’s food store