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Flashcards in Reproduction in Plants Deck (18)
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1

Male parts of a plant

- Stamen consists of anther and filament

2

Female parts of a plant

- Carpel consists of stigma, style and ovary

3

State the functions of the sepals, petals, anthers,
stigmas and ovaries

- Sepals: protect flower when it's a bud
- Petals: bright-coloured and scented, have nectary at base to attract insects
- Anthers: where pollen is made
- Stigma: for pollen grains to reach to the ovaries
- Ovaries: contain ovules. Each ovule has an egg cell

4

Characteristics of insect-pollinated flowers

- Petals: large and colourful to attract insects
- Nectary: sweet sugary fluids to attract insects
- Scent: strong, sweet and attractive
- Stigma: sticky and fury for insects to rub against
- Pollen: large and heavier
- Anther: sometimes enclosed

5

Characteristics of wind-pollinated flowers

- Absent of petals, nectary and scent
- Stigma: feathered => large surface area to increase pollination. feathered to catch pollen grains in air
- Pollen: light and in large quantities
- Anther: exposed
- Filament: for anther to be exposed

6

Define pollination

the transfer of pollen grains from the male part of the plant (anther of stamen) to the female part of the plant (stigma)

7

Distinguish between self-pollination and
cross-pollination

- Self pollination: pollen is transferred from the anther to the stigma of the same flower or to a different flower but on the same plant
- Cross pollination: pollen is transferred from the anther to the stigma of another plant of the same species

8

Discuss the implications to a species of selfpollination and cross-pollination

- Cross pollination ensures exchange in genetic material => greater variation
- Self pollination => advantageous features can be passed down. Also an advantage where there's no insects

9

Advantages of asexual reproduction

- Can reproduce rapidly
- Advantageous features can be passed down through alleles

10

Disadvantages of asexual reproduction

- Little/ no variation
- Diseases from parent cell can be passed down

11

Describe the growth of the pollen tube

- Pollen grains land on ripe stigma => start to grow => each grow a pollen tube which grows down the style to the ovary
- As it grows, get nutrients from the tissues of the style and carry male gamete nucleus with it
- First pollen tube to reach the ovary, enters the ovule through micropyle => male and female gametes fuse => fertilisation

12

Outline the formation of a seed and fruit

- Zygote divides and grows into an embryo. Ovule forms seed with embryo inside it
- Ovary forms fruit with seeds in it

13

Seed and fruit dispersal by wind and by animals provide what

a means of colonising areas. Without dispersal, new plants would be too crowded, competing for space, light, water and nutrients

14

Define dormancy

a period in which a plant does not grow as it awaits necessary environmental conditions such as temp, moisture

15

How seeds grow

- Stage 1: testa splits and radicle emerges
- Stage 2: epicotyl elongates, radicle grows into soil
- Stage 3: epicotyl pulls plumule out from the cotyledons
- Stage 4: epicotyl pulls plumule backwards through soils so leaves aren't damaged, lateral roots develop
- Stage 5: once above soil, epicotyl straightens and leaves are opened, roots develop rapidly

16

Conditions for germination

- Water is needed for seeds to swell. Swelling breaks testa. Cell absorbs water, develop vacuole and expand => cause radicle to grow. Water is also needed to activate enzymes
- Oxygen for aerobic respiration to provide embryo energy
- A suitably warm temp => enzymes can work efficiently

17

Difference between growth and development

- Growth: permanent increase in size and dry mass by an increase in cell size or number or both
- Development: increase in complexity

18

Why don't we measure wet mass?

Water content of a plant depends on water availability => quantity can vary