3a - Reproduction in plants Flashcards
How can plants reproduce?
- asexually
- sexually
How are new cells produced in plants asexually?
by mitosis
When plants reproduce asexually, their offspring is ___________ identical
genetically
How do plants reproduce asexually?
- many plants develop underground food storage organs that later develop into a plant (potato plants, daffodil plants)
- some plants produce side branches with plantlets on them (spider plant, chlorophytum)
- other plants produce runners with plantlets on them (strawberries)
- artificially induced (cuttings) that are placed in damp compost
What are the pros of asexual reproduction?
- produces a large quantity of plants very quickly
- can grow plants all year round
- can grow rare or endangered plants to increase the populations
- genetic modification can be introduced to large numbers of plants
What are the cons of asexual reproduction?
- vulnerable to pests/ same disease
- requires sterile lab facilities
- produces a large quantity of plants very quickly
What is the male gamete in plants called?
pollen
what is the female gamete in plants called?
egg cell (ovum)
Where are the male gametes produced?
in the anthers of the stamen
Where are the female gametes produced?
in the ovules in the ovaries
What type of petals do insect pollinated flowers have and why?
- colourful
- large
- to attract pollinating insects
What type of stigma do insect pollinated flowers have and why?
- within the flower
- sticky
- easier for pollen to stick to stigma
What type of filaments do insect pollinated flowers have and why?
- upright
- within the flower
- so the insects rubs against them to deposit the pollen as it crawls in
What type of pollen do insect pollinated flowers have and why?
- heavy
- sticky
- to stick easier to the anthers
What type of scent do insect pollinated flowers have and why?
- present
- to attract pollinating insects
What type of nectaries do insect pollinated flowers have and why?
- present
- to attract pollinating insects
What type of petals do wind pollinated flowers have and why?
- small
- green
- no need to attract insects
What type of stigma do wind pollinated flowers have and why?
- outside the flower
- feathery
- to catch pollen carried by the wind
What type of filaments do wind pollinated flowers have and why?
- hang outside of the flower
- so that pollen can easily be blown away
What type of pollen do wind pollinated flowers have and why?
- light
- so that it can easily be carried by wind
What type of scent do wind pollinated flowers have and why?
- absent
- no need to attract insects
What type of nectaries do wind pollinated flowers have and why?
- absent
- no need to attract insects
What is fertilisation in plants?
The fusion of the nucleus of a male gamete (pollen) and a female gamete (ovule) to produce a zygote that undergoes cell division and develops into an embryo
Describe stage 1 of fertilisation in plants:
- pollination occurs (either by wind or insects)
Describe stage 2 of fertilisation in plants:
- pollen lands on stigma
- pollen grows a pollen tube down the style using digestive enzymes towards the ovary
- pollen enters the ovule via an opening called the micropyle
Describe stage 3 of fertilisation in plants:
- the nucleus of the pollen grain travels down the pollen tube to fertilise the egg cell inside the ovule
Describe stage 4 of fertilisation in plants:
- fertilised egg develops into an embryo
- ovule becomes the seed
- ovary becomes the fruit
What does the ovule become?
the seed
What does the ovary become?
the fruit
What does the ovule wall become?
the seed coat
What is the embryonic plant made of?
- radicle (small root)
- plumule (small shoot)
Why do plants not want their seeds to land next to them?
The seeds will be in direct competition with the plant decreasing the chance of germination
What are some ways seeds are dispersed?
- animals (seed has hooks which catch onto animal fur)
- animals (fruit is eaten by animal, seeds are deposited in the droppings elsewhere)
- pods which are explosive, fire the seeds away
- small feather-like structure to help it float in the wind
- wings to help them fly in the wind
What specific conditions does a seed require to germinate?
- water
- oxygen
- warmth
Why do seeds need water to germinate?
to activate enzymes which digests stored food
Why do seeds need oxygen to germinate?
needed for the lease of energy for germination
Why do seeds need warmth to germinate?
needed for the enzymes to work effectively
