More Reproduction Flashcards

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1
Q

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

A

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

Progesterone maintains the uterus lining and stops LH.

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2
Q

Insect pollinated

A

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

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3
Q

Wind pollinated

A

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

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4
Q

What stimulates the development of secondary sexual characteristics

A

Oestrogen and testosterone

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5
Q

Sexual

A

Requires fertilisation

Two gametes needed

Two parents needed

Variation in offspring

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6
Q

Asexual

A

Does not require fertilisation

No gametes

Cells divide by mitosis

One parent

Genetically identical offspring

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7
Q

Stigma

A

Female

The part of the carpel where pollen lands during pollination

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8
Q

Ovary

A

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

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9
Q

Ovule

A

Contains an egg sac that surrounds the egg cell

Female gametes

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10
Q

Sepal

A

Protects the flower in the bud

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11
Q

Anthers

A

Contain cells which produce the male gamete

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12
Q

Filament

A

Joins the anther to the rest of the flower

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13
Q

Nectary

A

Makes nectar and attracts insects

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14
Q

Pollen

A

The male gamete

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15
Q

Mitosis

A

Division of body cells

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16
Q

Meiosis

A

Division of gametes

17
Q

Fertilisation

A

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.

18
Q

An egg cell is large so that

A

It can store a lot of carbohydrates for energy

19
Q

What carries speed from the testes to the penis

A

The sperm duct

20
Q

What fluid surrounds the baba

A

Amniotic fluid

21
Q

When does reproduction in plants occur?

A

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

22
Q

What stimulates the pollen tube to grow?

A

The pollen grain landing on the stigma

23
Q

How does the pollen tube grow through the style

A

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

24
Q

The growth of the pollen tube leads to…

A

Fertilisation

25
Q

Fertilisation leads to….

A

Seed formation.

26
Q

After fertilisation

Ovule

Ovary

A

Ovule-seed

Ovary-fruit

27
Q

Steps of seed formation

A

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

28
Q

Micropropagation

A

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

29
Q

Size and examples and other names for explants

A

Cuttings
0.5-1mm
Tips of shoots/roots

30
Q

Micropropagation stages

A

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

31
Q

Advantages

A

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

32
Q

Disadvantages

A

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

33
Q

What happens during pollination in plants

A

The pollen grains from the anther transfer to the stigma

34
Q

Why does pollination happen

A

So that the male gametes can reach the female gametes

35
Q

asexual reproduction

A

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

36
Q

Can you think of 3 organisms that reproduce asexuaslly?

A

bacteria
types of fungi
strawberries

37
Q

steps of plant fertilisation

A

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