reproduction Flashcards
what are the advantages of asexual reproduction?
- useful when the environment is stable
- completed much faster
- enables an organism to quickly populate
- more time + energy efficient
- if it’s well adapted to its environment, successful characteristics are carried on
what are the disadvantages of asexual reproduction?
- disease likely to affect the whole population as there is no genetic variation
- population is only suited to one habitat
- population is vulnerable to changes in conditions
- limited genetic variation in population
what are the two types of cell division?
mitosis and meiosis
what is the use of meiosis?
to produce gametes for sexual reproduction
what is the use of mitosis?
growth and repair
how many daughter cells are made in mitosis?
two genetically identical daughter cells
are offsprings from sexual reproduction genetically identical?
no, they are genetically different
how many chromosomes do the daughter cells contain and why is this important?
- 23 (a haploid amount)
- important so zygote has correct number when gametes fuse
how many daughter cells are produced in meiosis?
4 genetically different daughter cells
how many cell divisions occur in mitosis and meiosis?
- 2 cell division in meiosis
- 1 cell division in mitosis
how does sexual reproduction lead to variation in offspring?
there are two parent cells, so two sets of genetic information
where does mitosis occur?
all body cells, except the gametes
where does meiosis occur?
only in the gametes
what is the function of the sepal?
to protect the unopened flower
what is the function of the petal?
may be brightly coloured to attract insects
what is the function of the stamen?
male part of the flower, comprising an anther attached to the filament
what is the function of the anther?
produces the male sex cells (pollen)
what is the function of the stigma?
the top of the female part go the flower, which collects pollen grains
what is the function of the ovary (plants)?
produces the female sex cells (contained in the ovules)
pollination definition.
pollination is the transfer from anther to stigma of a plant
position of stamen in insect pollinated plants
enclosed so the insect has to make contact
position of stamen in wind pollinated plants
exposed so pollen can easily blow away
position of stigma in insect pollinated plants
enclosed so insect has to make contact
position of stigma in wind pollinated plants
exposed to catch pollen blowing in the wind
type of stigma in insect pollinated plants
sticky so pollen grains can attach from insects
type of stigma in wind pollinated plants
feathery so it can catch pollen grains blown by
size of petals in insect pollinated plants
large and colourful to attract insects
size of petals in wind pollinated plants
small because it doesn’t need to attract insects