Plant reproduction Flashcards
How is:
Growth controled in plants
Hormones
e.g. auxin
What is a:
tropism
a growth response in a plant to a stimulus
Do plants:
Grow away or towards light
- stems are positively photoropic as they grow towards light
- Roots grow away from light
What is a:
Response to light, water and gravity
- phototropism
- hydrotropism
- geotropism
Are plants:
geotropic?
- Stems are positively geotropic
- roots are negatively geotropic
What is the function of:
Roots
- Provides stability
- absorbs water and mineral ions
What is the advantages of:
stems and roots tropisms
- stem growing towards light leads to higher light absorbtion, photosynthesis
- more chance of finding light by growing upwards
- less chance of drying out when shielded from the sun
- more chance of finding moisture and stability in the ground
What are:
Tropisms caused by
Hormone Auxin
How does:
Auxin promote growth
- Auxin is in shoot tip
- Goes towards the side recieveing the least light
- If light is from above, growth will be equal on both sides
- if light is from a side, auxin → shady side → plant cells elongate → bend in plant stem
What are the characteristics of:
Asexual reproduction
(plants)
- 1 parent
- Offspring are identical
- rapid reproduction in favourable conditions
- mitosis
What are the characteristics of:
Sexual reproduction
- 2 parents
- fusion of 2 gametes
- gametes of plants are the pollen nucleus and the egg cell
- variety as DNA comes from 2 parents
- meiosis
What are the characteristics of:
Asexual reproduction
(bacteria)
- binary fission
- a cell splits into 2
- Very fast process that can occur up to every 20 minutes
How do plants:
Reproduce asexually
- underground food storage organs that develop into plants (potatoes)
- side branches that grow new plants (strawberries)
- (artificial cuttings) branch from parent plant is cut off
- planted in damp compost
- use auxin hormone to promote root growth
- cover with a clear plastic bag to keep warm
What are:
Flowers
Organs of sexual reproduction in plants
What is the definition of:
Sexual reproduction
Production of a new individual resulting from the fusion of 2 gametes.
(fusion is called fertilisation)
How does a:
plant relying on insect pollination attract insects?
- scent
- colour
- nectary
What is the function of:
Petals
Brightly coloured to attract pollinators to the flower
What is the function of:
Anther
Part of the Stamen that contains pollen
What is the function of the:
Filament
Holds the anther, making it accesible to insects or wind
What is the function of the:
style
carries pollen from stigma to ovary through pollen tube
What is the function of the:
Ovary
Produces femal gametes
What is the function of the:
Ovules
Contains female gametes
What is the function of:
nectary
secretes nectar to attract insects and spreads pollen around the insect
What is the function of the:
sepals
Provides support and protection for the flower as it is about to bud
What is the function of the:
Stamen
Pollination (male part of plant)
What is the function of the:
Carpel
Fertilisation of an egg (female part of a plant)
REVISE STRUCTURE OF A PLANT
(revision poster)
What is:
Pollination
the transfer of pollen from the anther to the stigma of a plant
What are the:
different types of pollination
- same flower = self-pollination
- different flowers = cross pollination
What is:
Wind pollination
and characteristics
- Transfer of pollen by the wind
- have no petals or dull
- no nectary
- no scent
- wide SA stigma to recieve pollen, and feathery
- Stamen is outside the flower
What is:
Fertilisation
The fusion of a male and female gamete to produce a zygote that undergoes cell devision and develops into an embryo
What causes the:
Pollen to move down to the ovule
- Sugary solution causes a pollen tube to grow
- grows towards ovaries
- each sugary formula is different, so only members of the same species are pollinated
What is the process of:
Fertilisation
- Pollination occurs through insects of the wind
- Pollen lands on stigma. A sugary solution causes a pollen tube to grow down the style using digestive enzymes towards the ovary
- the pollen tube enters the ovule via an opening called the micropyle. The nucleus of the pollen travels down the tube to fertilise the egg
- The fertilised egg develops into an embryo. The ovule becomes the seed and the ovary becomes the fruit
What is:
Seed dispersal
Dispersing a seed away from the parent plant to avoid competition
What is:
Germination
Development of a seed into a plant
What are the:
Conditions needed for germination
Water
Oxygen
Warmth
WOW
What is the purpose of:
Water in germination
activate enzymes which digest stored food
What is the purpose of:
Oxygen in germination
needed for release of energy through aerobic respiration
What is the purpose of:
Warmth in germination
so that enzymes work at their optimum temperature
