Section 7 - Reproduction and Inheritance Flashcards
What are the male and female structures in flowering plants? (2)
Male - Stamen Female - Carpel
What does the stamen consist of; and what do the parts do? (4)
Anther - contains pollen grains; which produce male gametes
Filament - stalk that supports the anther
What does the carpel consist of; and what do the parts do? (6)
Stigma - End bit that pollen grains attach to
Style - Rod like section that supports the stigma
Ovary - Contains female gametes (eggs)
What is pollination? (2)
- Transfer of pollen from an anther to a stigma
- So that the male gametes can fertilise the female gametes in sexual reproduction
What is cross-pollination? (3)
- A type of sexual reproduction
- Where pollen is transferred from the anther of one plant to the stigma of another
- Plants that rely on cross pollination rely on things like insects or the wind to help them pollinate
How are plants adapted for insect pollination? (4)
- Brightly coloured petals : to attract insects
- Scented flowers and nectaries : to attract insects
- Big sticky pollen grains : the grains stick to insects as they go from plant to plant
- Sticky stigma : so any pollen picked up by insects on other plants will stick to the stigma
How are plants adapted for wind pollination? (5)
- Small, dull petals : to not attract insects
- No nectaries or strong scents : to not attract insects
- A lot of pollen grains : small and light, to be carried by the wind
- Long filaments that hang the anthers outside the flower : so that a lot of pollen gets blown away by the wind
- Large and feathery stigma : to catch pollen as it’s passed away, which often hangs outside the flower
How does fertilisation happen in plants? (4)
- A pollen grain lands on the stigma of a flower
- usually with help from insects or the wind
- A pollen tube grows out of the pollen grain and down through the style to the ovary
- A nucleus from the male gamete moves down the tube to join with a female gamete in the ovary
What are the right conditions for germination; and what will seeds do if the conditions aren’t right? (4)
- Water : to activate the enzymes that break down the food reserves in the seed
- Oxygen : For respiration, which provides the energy for growth
- A suitable temperature : For the enzymes inside the seed to work, depends on what type of seed
- Seeds will lie dormant until the conditions around it are right for germination
Advantages and disadvantages of taking cuttings from plants (3)
- AD : plants can be produced quickly and cheaply
- AD : You can be sure of their characteristics
- DIS : lack of genetic variation; expossure to disease or changes in environmental conditions, all of them will be affected.
What is insect pollination (3)
- Transfer of pollen
- from anther to stigma
- by insects
Give an example of artifical asexual reproduction in plants (3)
- Gardeners use cuttings
- Take cuttings from good parent plants
- Plant them to produce clones of the parent plant
Give an example of natural asexual reproduction in plants (6)
- Strawberry plants
- Parent strawberry plant sends out runners
- Runners are fast growing stems that grow out sideways, just above the ground
- Runners take root at various points a short distance away
- New plants start to grow
- Genetically identical
Explain how a plants leaf mesophyll tissue being eaten affects the growth of the plant (3)
- Less surface area to absorb sunlight
- Less chloroplasts
- Less light, less photosyenthesis
Describe what is meant by the term insect-pollination (2)
- transfer of pollen by insect - from anther/stamen to stigma
Give two ways in which the structure of a wind pollinated flower would differ from an insect pollinated flower (4)
- less bright and smaller petals
- stamens/anthers outside flower
- no nectary
- stigma feathery
