Sexual Reproduction in Flowering Plants Flashcards
Draw the structure of a flower.
.
What is the function of the sepal?
To protect the flower (and to prevent it from drying out)
What is the function of the petal?
To attract insects to the flower for pollination
What is the function of the stamen?
To produce the pollen grains in the anthers. (Each pollen grain produces two male gametes, one of which can fertilise an egg cell)
What is the function of the anther?
Produces pollen
What is the function of the filament?
Holds the anther in place
What is the function of the carpel?
To produce the ovules (Each ovule contains an egg cell inside an embryo sac)
What is pollination?
Transfer of pollen from the anther to the stigma of a flower of the same species
What is the function of the stigma?
Where pollen lands after pollination
What is the function of the style?
Pollen travels down this
What is the function of the ovary?
Contains ovules
What is self pollination?
Transfer of pollen from an anther to a stigma of the same plant
What is cross-pollination?
Transfer of pollen from the anther to the stigma of a different plant of the same species
What adaptations do flowers have for animal (insect) pollination?
Petals brightly coloured, scented with nectaries.
Small amounts of sticky pollen.
Anthers inside petals.
Stigmas sticky, inside petals.
What adaptations do flowers have for animal (insect) pollination?
Petals small, not coloured brightly.
Anthers outside petals.
Stigmas large, feathery and outside petals.
Pollen Large numbers, light, dry and small.
What is fertilisation in plants?
Fertilisation is the fusion of the male (n) and female (n) gametes to produce a zygote (2n).
What type of gamete does the pollen grain produce?
The male gamete
What type of gamete does the embryo sac in a plant produce?
An egg cell and polar nuclei
How do seeds form after a zygote is formed?
The zygote grows repeatedly by mitosis to form an embryo.
What does and embryo consist of?
An embryo consists of a plumule (future shoot), a radical (future root) and cotyledons (food stores needed for germination)
What happens to the endosperm nucleus and what does it then act as? What is an example of one?
The endosperm nucleus (3N) divides repeatedly to form the endosperm in endospermic seeds. This endosperm acts as a food store for the developing seed e.g. maize
What happens to the endosperm in non endospermic seeds? Where is food stored in these seeds and what is an example of one?
In non-endospermic seeds the endosperm is used up in the early stages of seed development so the food is stored in the cotyledons e.g. bean
What is an endosperm?
A food store for developing embryo
What is in all seeds?
An embryo with a plumule (immature shoot), radicle (immature root) and cotyledon (food supply or seed leaf)
What is in some seeds?
An endosperm which is a food store
What are the two features that seeds are classified according to?
Number cotyledons (Seed leaves) Presence of endosperm
What are the two types of seeds as classified according to number of cotyledons (seed leaves)? Give examples.
Monocotyledon - one cotyledon e.g. maize.
Dicotyledon - two cotyledons e.g. broad bean
What are the two types of seeds as classified according to presence of endosperm? Give examples.
Present - endospermic e.g. maize
Absent - non-endospermic e.g. broad bean
What are differences between monocots and dicots?
Monocots have 1 cotyledon, parallel venation, scattered vascular bundle arrangement and petals usually in multiples of 3.
Dicots have 2 cotyledons, reticulate (net) venation, vascular bundle arrangement in a ring and petals usually in multiples of 4 or 5.
What are the features of a monocot?
Monocots have 1 cotyledon, parallel venation, scattered vascular bundle arrangement and petals usually in multiples of 3.
What are the features of a dicot?
Dicots have 2 cotyledons, reticulate (net) venation, vascular bundle arrangement in a ring and petals usually in multiples of 4 or 5.