More Reproduction Flashcards
What are the roles of oestrogen and progesterone in the menstrual cycle.
Oestrogen causes the uterus lining to thicken, stops FSH and releases LH.
Progesterone maintains the uterus lining and stops LH.
Insect pollinated
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
Wind pollinated
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
What stimulates the development of secondary sexual characteristics
Oestrogen and testosterone
Sexual
Requires fertilisation
Two gametes needed
Two parents needed
Variation in offspring
Asexual
Does not require fertilisation
No gametes
Cells divide by mitosis
One parent
Genetically identical offspring
Stigma
Female
The part of the carpel where pollen lands during pollination
Ovary
Sits at the base of the carpel and protects the female gamete from the dry air outside
Ovule
Contains an egg sac that surrounds the egg cell
Female gametes
Sepal
Protects the flower in the bud
Anthers
Contain cells which produce the male gamete
Filament
Joins the anther to the rest of the flower
Nectary
Makes nectar and attracts insects
Pollen
The male gamete
Mitosis
Division of body cells