Unit 4 Sexual Reproduction In plants Flashcards
(35 cards)
What is the receptacle in a flower?
The top of the flower stalk from which the different parts of the flower develop.
What are sepals?
The first set of modified leaves that protect the flower while it’s still forming and before the flower bud opens.
What is the function of petals?
They are often large, coloured, and patterned to attract insects; some colours, e.g., UV, are not visible to humans but are visible to insects.
What components make up the stamen?
The filament and anther.
What is the role of the anther?
It is the male reproductive organ of a flower, the site of meiosis and mitosis to produce male gametes.
What does the carpel consist of?
The ovary, style, and stigma.
What is the function of the ovary in the carpel?
It is the site of meiosis to produce female gametes contained within the ovules.
What happens to the ovules after fertilisation?
They become the seeds.
What is the purpose of the style in the carpel?
It supports the stigma.
What is the stigma?
A sticky surface that pollen grains land on during pollination.
What are nectaries?
Structures that secrete nectar, attracting insects and other animals that carry pollen from one flower to another.
True or False: The anther is part of the female reproductive organ of a flower.
False.
Fill in the blank: The _______ is the male reproductive organ of a flower.
stamen
Fill in the blank: The _______ is a sticky surface that pollen grains land on during pollination.
stigma
Which animals can be attracted to nectar secreted by flowers?
Insects, hummingbirds, bats, mice.
What is absent in wind-pollinated flowers?
- Petals
- Scent
- Nectaries
How are the anthers and stigma positioned in wind-pollinated flowers?
hang outside the flower for easy pollen shedding and pickup.
The anther is attached loosely to allow pollen to be shaken into the air.
What adaptations do wind-pollinated flowers have to aid pollen dispersal?
- Anthers loosely attached
- Feathery stigmas to increase surface area
- Small and light pollen
- Pollen may have air sacs
Why do wind-pollinated flowers produce large quantities of pollen?
To increase the chance of pollen landing on a stigma of the correct species.
This strategy compensates for the random nature of wind dispersal.
What is the most common type of wind-pollinated flowers?
Grasses
What is chemical self-incompatibility in flowers?
Gametes from the same parent plant are unable to fuse and form a zygote or, if the zygote forms, it fails to develop.
This adaptation prevents self-fertilization and promotes genetic diversity.
What is an example of irregular flower structure that aids cross-pollination?
Primrose (Primula vulgaris)
stigma of the pin-eyed is above the anthers, preventing self-pollination.
What is dichogamy in flowering plants?
Anthers and stigmas mature at different times.
—>prevent self-pollination.
What are monoecious plants?
Plants that have separate female and male flowers on the same plant, —>cross-pollination
