Plant Reproduction

Question 1

When an insect carrying pollen lands on the flower describe the events that lead to seed formation

Answer 1

When it lands the stigma inside the flower brush against the insect. It is sticky so the pollen sticks to it. A pollen tube then grows down the style towards the ovary and enters the ovary via the micropyle (small hole in ovary) at this point fertilisation occurs and the ovule developed into a seed which developed into a fruit. (Ovule wall becomes seed coat)

Question 2

What does the radicle become?

Answer 2

The first root

Question 3

What does the plumule become

Answer 3

The first shoot

Question 4

What does the cotyledon become

Answer 4

The first leaf and food store

Question 5

What is function of the testa?

Answer 5

It covers and protects the embryo before germination (seed coat)

Question 6

What is dormancy?

Answer 6

The period of time between fertilisation and germination

Question 7

What is germination

Answer 7

The process by which a seed changes into a plant. Root, shoot appears the seed cost splits.

Question 8

Why is water needed for germination

Answer 8

Water is needed in order to burst that tests and allows the radicle and plumule to develop. It also allows metabolic reactions to happen as it activates enzymes

Question 9

Why is oxygen needed for seeds to germinate

Answer 9

Oxygen is needed for aerobic respiration to happen

Question 10

Why is a warm temperature needed for germination?

Answer 10

A warm temperature not only lets the seed know when it should germinate but it also lets rapid enzyme reactions to happen.

Question 11

What is a zygote?

Answer 11

The 1st cell after fertilisation when the diploid number has been restored.

Question 12

What is the stamen made up of, where is it and what does it do?
Insect pollinated

Answer 12

The stamen is made up of the anther and the filament (which holds up the anther)
They are the long stick things inside the flower.
They produce pollen grains which stick or hook onto the insects. The anther and filament are firm and stiff to brush against the insects.

Question 13

What is the stigma and where is it?

Insect pollinated

Answer 13

The stigma is also inside the flower and the stamen are on top of it. It is sticky so pollen grains stick onto it when an insect brushed past.

Question 14

What do petals look like on insect pollinated flowers?

Answer 14

They are large and brightly coloured to attract insects

Question 15

How else to insect pollinated flowers attract insects

Answer 15

They have sweet, sugary nectar which attracts insects.

Question 16

Where is the stamen and what does it do?

Wind pollinated flower

Answer 16

The stamen is outside the flower and the anthers are loose on long filaments so pollen grains are released easily, the grains are smooth and lights so can be carried by the wind and not clump together

Question 17

Where is the stigma and what does it do

Wind pollinated flower

Answer 17

It is outside and feathery to catch drifting pollen grains

Question 18

What do the petals look like on a wind pollinated flower?

Answer 18

They are small and usually green or brown.

Question 19

What is the definition of pollination?

Answer 19

The transfer of pollen from the anther to the stigma then ovule to allow fertilisation to take place.

Question 20

What happens when pollen lands on the stigma?

Answer 20

A pollen tube is grown down the style and into the ovary, the nucleus of the pollen grains passes down the tube to fertilise the egg cell in the ovule (fertilisation). The embryo developed and the ovary forms the fruit and the ovules become seeds.

Question 21

What is germination?

Answer 21

The process where a plant grows from a seed.

Question 22

How do germinating seeds get their food before they can photosynthesise?

Answer 22

They use up their food stores until they can photosynthesise

Question 23

What is a gamete?

Answer 23

Also known as a sex cell. A female and male gamete undergo fertilisation to become a zygote. In a plant the female gamete is the egg and the male gamete is the pollen.

Question 24

What happens when plants asexually reproduce?

Answer 24

They produce a clone. Some plants have lateral buds on the outside which grows another plant others have side branches with plantlets on them (spider plant) and others produce runners which extend and grow a plant from that (e.g. Strawberry plants) this can be done artificially through tissue culture and taking cuttings