REPRODUCTION IN FLOWERING PLANTS Flashcards
Reproduction definition
It is the ability of organisms to produce a new generation of themselves this is important for survival and evolution because through reproduction and individual passes down the genes to the next generation
The two natural types of reproduction and some information about them
asexual reproduction and sexual reproduction.
asexual reproduction is the production of a new generation of the same species are one plant
sexual reproduction the production of a New generation of the same species by bringing together genetic material of two plants
similarity between asexual and sexual
Both processes produce the same kind of organisms to prevent species from dying out or becoming extinct and this results in food being produced which is vital to feed the world is growing population
look in the book for differences between them
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Advantages of a sexual reproduction
- all individuals can we produce offspring and no energy is required
- this process is simple and fast because it involves mitosis
- it is useful in on changing conditions
- A favourable mutation can spread rapidly which allows the population to adapt quickly to the new environmental changes
disadvantages of asexual reproduction
Unless a mutation occurs there is no variation in the offspring because there is no combination of alleles
Overcrowding may occur and resources like food might be in short supply
Advantages of sexual reproduction
It results in a variation which is in the basis of evolution
It gives organisms a better chance of survival and in unstable environment because offspring might be able to adapt to new conditions
it may prevent the spread of diseases because offspring maybe genetically resistant to a particular disease
it may reduce the chance of inheriting a disease from a parent
disadvantages of sexual reproduction
There is a high expenditure of energy as the plants special organs of reproduction need to be produced
reproduction is slower because it takes time for gametes to be produced and the meeting of gametes
Unfavourable mutations and recessive genes might be expressed in offspring
outside agents may be needed and plants to carry pollen or seeds
How does sexual reproduction take place
sexual reproduction is more complicated than asexual reproduction
diploid parent produces gametes in the gonads by meiosis
The male and female gametes are brought together by pollination or mating
gametes nuclei fuse and this process is called fertilisation
The new cell, the zygote is deployed and has two sets of chromosomes
this zygote grows by mitotic cell division into a new individual
The gametes
- female gametes are quite large and not motile
- in animals female gametes are known as an egg and ovum
- male gametes are small and motile in animals
- in animals male gametes are known as a sperm
in many plants make gametes is just a nucleus in a pollen grain
female gametes is an egg cell in an embryo sac
what is an angiosperm
Most of the plants you see are angiosperms. they are plants with flowers which produce their ovules enclosed in an ovary
gymnosperms are naked on a cone scale
where do angiosperms grow
they grow in almost every habitat, except the ocean, where the algae are found
what is a flower
A flower is the organ of sexual reproduction. It contains the reproductive organs and will often attract pollinators
Many flowers make both male and female . ( hermaphrodite ) means bisexual
where are male gametes found
inside the pollen grains produced by the anthers
where are female gametes found
inside the ovules which are enclosed by the ovary
