More Reproduction

Question 1

What are the roles of oestrogen and progesterone in the menstrual cycle.

Answer 1

Oestrogen causes the uterus lining to thicken, stops FSH and releases LH.

Progesterone maintains the uterus lining and stops LH.

Question 2

Insect pollinated

Answer 2

Contain large, colourful, scented petals.

Contains nectaries

Pollen grains have sticky or spiky outer walls

Stigmas are small and held inside the flower

Produce small amounts of pollen

Pollen is heavy

Question 3

Wind pollinated

Answer 3

Small petals (don’t get in the way when wind blows the pollen)

Green/tiny petals

No scent

No nectaries

Many anthers which are often large and hang outside the flower so pollen is easily dispersed.

Stigmas are large and feathery to trap pollen.
Hang outside the flower.

Produce large amounts of pollen

Pollen is lightweight

Question 4

What stimulates the development of secondary sexual characteristics

Answer 4

Oestrogen and testosterone

Question 5

Sexual

Answer 5

Requires fertilisation

Two gametes needed

Two parents needed

Variation in offspring

Question 6

Asexual

Answer 6

Does not require fertilisation

No gametes

Cells divide by mitosis

One parent

Genetically identical offspring

Question 7

Stigma

Answer 7

Female

The part of the carpel where pollen lands during pollination

Question 8

Ovary

Answer 8

Sits at the base of the carpel and protects the female gamete from the dry air outside

Question 9

Ovule

Answer 9

Contains an egg sac that surrounds the egg cell

Female gametes

Question 10

Sepal

Answer 10

Protects the flower in the bud

Question 11

Anthers

Answer 11

Contain cells which produce the male gamete

Question 12

Filament

Answer 12

Joins the anther to the rest of the flower

Question 13

Nectary

Answer 13

Makes nectar and attracts insects

Question 14

Pollen

Answer 14

The male gamete

Question 15

Mitosis

Answer 15

Division of body cells

Question 16

Meiosis

Answer 16

Division of gametes

Question 17

Fertilisation

Answer 17

Happens in the Fallopian tube and involves the fusion of a male and female gamete which produces a zygote. This then becomes an embryo by mitosis.

Question 18

An egg cell is large so that

Answer 18

It can store a lot of carbohydrates for energy

Question 19

What carries speed from the testes to the penis

Answer 19

The sperm duct

Question 20

What fluid surrounds the baba

Answer 20

Amniotic fluid

Question 21

When does reproduction in plants occur?

Answer 21

When the male nucleus from the pollen grain fuses with the female egg in the egg sac

Question 22

What stimulates the pollen tube to grow?

Answer 22

The pollen grain landing on the stigma

Question 23

How does the pollen tube grow through the style

Answer 23

It used enzymes to break through the style and then enters the ovule

Question 24

The growth of the pollen tube leads to…

Answer 24

Fertilisation

Question 25

Fertilisation leads to....

Answer 25

Seed formation.

Question 26

After fertilisation Ovule Ovary

Answer 26

Ovule-seed Ovary-fruit

Question 27

Steps of seed formation

Answer 27

1- zygote transforms into an embryo with a small root and shoot. 2-the other parts of the ovule then become cotyledons 3- the ovule will become the seed coat (testa) 4- the ovary will become the fruit coat

Question 28

Micropropagation

Answer 28

The culture of explants in the lab to produce many clones of a single plant. (Artificial cloning)

Question 29

Size and examples and other names for explants

Answer 29

Cuttings 0.5-1mm Tips of shoots/roots

Question 30

Micropropagation stages

Answer 30

1- explants is scraped from the parent plant. 2-cut and trim to shape 3-explants are placed in agar growth medium containing nutrients and auxins. 4- samples develop into tiny plantletes 5- plant legs are planted into compost

Question 31

Advantages

Answer 31

Less likely to contain viruses Good for research cos identical Easier to produce plants that are difficult to grow from seeds Guarednteed production of identical plants with desirable characteristics Fast, requires small space

Question 32

Disadvantages

Answer 32

Something goes wrong, can't tell till too late then loads of dodgy plants Interferes with nature Reduces genetic variation and therefore increases vulnerability to change

Question 33

What happens during pollination in plants

Answer 33

The pollen grains from the anther transfer to the stigma

Question 34

Why does pollination happen

Answer 34

So that the male gametes can reach the female gametes

Question 35

asexual reproduction

Answer 35

involves no fertilisation between male and female gametes. Offspring are genetically identical to their parents

Question 36

Can you think of 3 organisms that reproduce asexuaslly?

Answer 36

bacteria types of fungi strawberries

Question 37

steps of plant fertilisation

Answer 37

Pollen is transferred from one flower to another either by wind or insects Pollen lands on stigma and grows a pollen tube down through the style and towards the ovary The nucleus of the pollen grain passes down the tube and fertilises the egg cell inside the ovule The fertilised egg develops into an embryo; the ovary forms the fruit and the ovule forms the seed