D3.1 - plant reproduction (5i) Flashcards
what are the elements of a flower reproductive system?
- Anther
- Filament
- Septal
- Nectary
- Petal
- Stigma
- Style
- Ovary
what is the role of the anther?
produces and releases the pollen grains, which contain the male nuclei
what is the role of the filament?
holds up the anther
what is the role of the petal?
colorful to attract pollinating insects
what is the role of the stigma?
sticky region that receives the pollen
what is the role of the style?
supports the stigma
what is the role of the nectary?
produces sweet nectar to attract pollinating insects
what is the role of the ovary?
containing ovules, where the female nuclei develop
what is the role of the sepal?
protects the developing flower, while it is in the bud
what is the process of sexual reproduction in flowering plants?
reproduction in flowering plants is sexual, even if a plant species is hermaphroditic e.g) sunflowers and orchids
- production of haploid gametes using meiosis.
- ovules (female gametes) are produced in the ovary
- pollen grains (male gametes) are produced in the anthers - pollination - transfer of pollen between flowers from anther to stigma
- the pollen grain grows into a structure called a pollen tube, which penetrates down the style
- the pollen tube delivers the male reproductive nuclei to the female nuclei within the ovules inside the ovary of a flower
- fertilization - fusion of male and female nuclei to produce an embryo
- seed develops from fertilized ovule, while fruit develop from the whole ovary
- seed dispersal - seeds are distributed away from the parent plant via self-explosion, wind or animals
- seeds germinate when conditions are appropriate
what is cross-pollination?
cross pollination is the transfer of pollen produced on one plant to another plant
what is the impact of cross-pollination?
cross pollination increases genetic variation within a species
what impact does self-pollination have on a plant species?
self-pollination leads to inbreeding, which decreases genetic diversity and healthy growth
What does hermaphroditic mean?
contains both male and female structures and is able to fertilise itself can reproduce
what are 4 methods of preventing self-pollination?
- different maturation times for pollen and stigma or ovules
- genetic mechanisms where protein interactions occur when pollen lands on the stigma within the same plant, preventing reproduction from continuing in a variety of different ways
- having separate male and female flowers on a plant
- having separate male and female plants within a species