Reproduction in plants

Question 1

What does the sepal do?

Answer 1

Protects the unopened flower

Question 2

What do the petals do?

Answer 2

They are brightly colored in insect-pollenated plants to attract insects

Question 3

What does the anther do?

Answer 3

Produces and releases the male sex hormone (Pollen grain)

Question 4

What does the stigma do?

Answer 4

Top of the female part of the flower which collects pollen grains

Question 5

What does the ovary do?

Answer 5

Produces the female sex hormone (Ovum)

Question 6

What is pollenation?

Answer 6

When pollen is transferred from the anthers to the stigma

Question 7

What is cross polination?

Answer 7

When pollen is transferred from a different flower

Question 8

What is self pollination?

Answer 8

When pollen is transferred from the same flower

Question 9

What is an insect pollenated plant?

Answer 9

When the pollen is transferred by insects (Or sometimes animals e.g. Bats or birds)

Question 10

What is a wind pollentated plant?

Answer 10

When pollen is transferred by the wind

Question 11

How do insects pollenate plants?

Answer 11

When insects enter a flower, they search for the nectar at the bottom. As they get that nectar, the insect’s body might brush against the anthers. When the insect visits a new plant they might brush against the stigma and therefore pollenate the plant.

Question 12

How do the petals adapt to insect pollenation

Answer 12

They are large and bright to attract insects

Question 13

How does the scent and nectar adapt to insect pollenation

Answer 13

They are present. The nectar and scent attract insects into the plant and push past the stamen to get the nectar

Question 14

How does the number of pollen grains adapt to insect pollenation

Answer 14

They are in moderate amounts. Insects transfer pollen grains efficiently with a high chance of successful pollenation

Question 15

How do the pollen grains adapt to insect pollenation

Answer 15

They are larger and sticky or spiky to attach to insects and be carried away

Question 16

How do the anthers adapt to insect pollenation

Answer 16

They are inside the flower, stiff and firmly attached to brush against insects

Question 17

How does the stigma adapt to insect pollenation

Answer 17

They are inside the flower and sticky, so pollen grains stick to it when the insect goes past

Question 18

How does wind pollenation work?

Answer 18

When ripe, the anthers open and shed their pollen into the air. The wind then blows this pollen until it lands on the stigma of a plant of the same species. Resulting in pollenation.

Question 19

How do the petals adapt to wind pollenation?

Answer 19

They are small and dull, often green or brown in colour

Question 20

How do the scent and nectar adapt to wind pollenation?

Answer 20

No scent. They don’t need to waste unnecessary energy on making a scent if they don’t need to attract insects

Question 21

How do the number of pollen grains adapt to wind pollenation

Answer 21

They are in large amounts. The more pollen there is the higher chance of pollination as most pollen grains are not transferred to another flower.

Question 22

How do the pollen grains adapt to wind pollenation

Answer 22

They are smooth and small to float in the wind

Question 23

How do the anthers adapt to wind pollenation

Answer 23

They are outside the flower and on loose filaments to release pollen grains easily

Question 24

How do the stigma adapt to wind pollenation

Answer 24

They are outside the flower and feathery to catch drifting pollen grains

Question 25

Describe how fertilisation and fruit formation happens:

Answer 25

• A pollen grain lands on the stigma and the pollen tube starts growing down into the style
  -The pollen tube then enters the ovule through the micropyle
• The pollen nucleus travels into the micropyle through the pollen tube and therefore fuses with the ovum nucleus resulting in fertilization
  -The ovary will develop into a fruit and the ovule develops into a seed

Question 26

What are the 3 key factors needed for seed germination?

Answer 26

Water- Swells the seed, breaks the seed coat, and activates enzymes for growth
Oxygen -Necessary for respiration to provide energy
Warmth- Boosts enzyme activity and improves germination until a certain temperature

Question 27

What is the apparatus needed to investigate the conditions of germination?

Answer 27

Test tubes
Test tube holder
Cress seeds
Cotton wool
Fridge

Question 28

What is the method for investigating the conditions of germination?

Answer 28

-Prepare 4 test tubes with 10 cress seeds on cotton wool label them a b c d
-Tube A: Dry cotton wool
- Tube B: Moist cotton wool
- Tube C: Cover the seeds and wool in water and a layer of oil
- Tube D: Moist cotton wool that gets left in a fridge
- Tubes ABC will be kept in room temp
Compare the amount of germinated seeds in each tube

Question 29

What are the results going to be from the investigation of conditions of germination?

Answer 29

Test tube A: Dry cotton wool- NO seeds germinated
Test tube B: Moist cotton wool- Seeds germinated
Test tube C: Water and a layer of oil- NO seeds germinated
Test tube D: Fridge- NO seeds germinated

Question 30

What is meant by the term germination?

Answer 30

The beginning of seed growth

Question 31

What do Cotyledons do?

Answer 31

They surround the embryo, storing food for the seedling. They also provide energy until the plant can photosynthesize

Question 32

What is meant by the term Runner?

Answer 32

Horizontal stems with small plantlets that grow sideways out of the parent plant. Once they hit the soil these plantlets will grow and become independent from the parent plant

Question 33

What is the method for cuttings?

Answer 33

-Gardeners take cuttings from good parents plants
- A section of the parent plant with a new bud is cut off
- This new cutting can be either placed into the water until new roots grow or directly into the soil
- Sometimes stems can be put into “rooting powder” which contains plant growth regulators that encourage new growth
- These cuttings will be genetically identical to the parent plant