Plant Reproduction

Question 1

Understand the differences between sexual and asexual reproduction

Answer 1

Asexual reproduction:
It’s the faster type of reproduction as a mate does not have to be found
It involves one parent
Does not lead to variation - clones are produced
Type of reproduction that is usually used by plants and insects
No fusion of gametes

Sexual reproduction:
The slower type of reproduction as a mate has to be found
Involves two parents
Leads to variation between the offspring
Type of reproduction which humans use to produce offsprings
Involves the joining of male and female gametes.

Question 2

Structure of a flower

Answer 2

Image on OneNote

Question 3

Flowers - gametes

Answer 3

The male gamete is made in the anther and is found inside the pollen grain.
The female gamete is found in the ovary and is called an ovule.

Question 4

Understand that plants can reproduce asexually by natural methods and by artificial methods

Answer 4

When you clip off a piece of a plant and put it to grow in new soil, you are making a clone of a plant. The new plant is identical to the plant that you took the clipping from
For example by using runners in strawberries. Or tubers in potatoes.

Question 5

Petals

Answer 5

Attracts pollinators

Question 6

Anther

Answer 6

Produced male sex cells

Question 7

Filament

Answer 7

Holds up the anther

Question 8

Stigma

Answer 8

Collects pollen grains

Question 9

Style

Answer 9

Holds the stigma up

Question 10

Ovary

Answer 10

Produced the female sex cells

Question 11

Ovules

Answer 11

Forms the seed of the plant

Question 12

Nectary

Answer 12

Produced a sugary solution called nectar which attracts insects

Question 13

Sepal

Answer 13

Protects the unopened flower

Question 14

1. What is pollination?

Answer 14

Pollination is the transfer from an anther to a stigma. For pollination to happen, the plants need help from outside such as insects or a gust of wind

Question 15

Insect pollinated flower - how they are adapted for pollination

Answer 15

Here’s how planets can be adapted by insects:

1. They have brightly coloured petals to attract insects.
2. Scented flowers to attract insects
3. The stigma is sticky so that any pollen picked up by insects on other plants will stick to the stigma.
4. Large petals for insects to land on
5. A few small anthers usually held inside the flower
6. Produce smaller amounts of pollen
7. Pollen is heavier

Question 16

Wind pollinated flower - how they are adapted for pollination

Answer 16

Here’s how plants can be adapted by the wind:

1. Small dull petals
2. No scent
3. Long filaments that hang the anthers out so that a lot of pollen gets blown away by the wind
4. Large feathery stigmas to catch pollen as it’s carried past by the wind
5. Pollen grains have smooth outer walls
6. Produce large amounts of pollen
7. Pollen is lightweight

Question 17

Self pollination and cross pollination

Answer 17

SELF POLLINATION – Is where the pollen is transferred from the anther from one plant to the stigma of the same plant. It is prevented by having the stigma above the stamen.

CROSS POLLINATION – Where the pollen is transferred from the anther from one plant to the stigma of a different plant.

Question 18

2. Fertilisation

Answer 18

Fertilisation is the joining of the nucleus from the male gamete with the nucleus inside the gg cell to make a zygote. This divides by mitosis to form am embryo.

Once the pollen is on the stigma, it grows a pollen tube which enters the ovule containing an egg cell. As it goes down the pollen tube, it grows down the style because it releases enzymes that digest a pathway.

Question 19

3. After fertilisation

Answer 19

After fertilisation, the petals, stamen and sepals fall off. The fertilised female gamete forms a seed. Water leaves the seed, it dehydrates and becomes dormant because metabolic reactions stops. The ovary develops into a fruit around the seed.

Question 20

4. Seed dispersal

Answer 20

The fruit is used for seed dispersal. The seed has to grow away from the parents plant so that they don’t compete for water, nutrients, light and space. There are different ways the fruits are moved away:

1. Some fruits are eaten by animals and the seeds come out of their faces.
2. Some fruits are carried on the fur of animals
3. Some fruits are carried by the wind
4. Some fruits explode, scattering the seeds

Question 21

5. Germination

Answer 21

Germination is when the seed grows into the baby plant. Water enters the seed through the hole and activates enzymes. The water softens the seed coat allowing it to split. The enzymes break starch down into maltose and then glucose. The glucose is used in respiration to provide energy for growth. The radicle is the first part to grow out of the seed as it needs to absorb more water.

While germinating, the plant uses food stores to provide energy for growth.

The conditions needed for germination to happen is water, oxygen and warmth.