reproduction in plants Flashcards
sexual reproduction defenition
process involving the fusion of the nuclei of 2 gametes to form a zygote .
what is a gamete
a sex cell
how many chromosomes are in a gamete
23 (haploid)
how many chromosomes does a zygote contain
46 ( diploid)
advantages of sexual reproduction
- increases genetic variation
- adapt to new environments
- disease is less likely to affect environment
disadvantages of sexual reproduction
- takes time and energy
- difficult for isolates memembers to reproduce
asexual reproduction defenition
process resulting in genetically identical offspring being produced from one parent
what type of offsprings does asexual reproduction make
genetically identical
how do bacteria reproduce
asexual reproudction
- binary fission
advanatages of asexual reproduction
- population can be increased rapidly
- can exploit sustainable environments quickly
- more time and energy efficeint
- reproduction is faster
disadvanatages of asexual reproduction
- limited genetic variation
- population vulnerable to changes in conditions
- diseases is likely to affect whole population
what type of cell division occurs in asexual reproduction
mitosis
fertillisation defenition
fusion of gamete nuclei
pollination meanig
where pollen is transferred by insects or by wind
parts of flowers
- sepal
- petals
- anther
- stigma
- ovary
- ovule
sepal
protects unpoened flower
petals
brightly colored insect pollinated flowers attract insects
anther
produced and releases the male sex cell
stigma
top of femal part of flower which collects pollen grains
ovary
produced the female sex cell
ovule
contains the female sex cell
process of pollination with insects
- insects visit flowers for nectar
- brushes against antheres which deposits sticky pollen onto insects body
- insect visit another flower, brushes against stigma and deposits pollen from first flower
petals in insect pollinated
large and brightly colored to attract insects
scent and nectar in insect pollinated
present
no. of pollen grains in insect pollinated
moderate
pollen grains in insect pollinated
larger, sticky, to attach to insects
anthers in insect pollinated
inside flower, stiff and firmly attahced
stigma in insect pollinated
inside flower, sticky so pollen grains stick to it
what happens to wind pollinated flowers when ripe
anthers open and shed their pollen into open air
cross pollination in flowers
when pollen from one plant is transferred to stigma of another plant of same species
self pollination in flowers
when pollen lands on the same plant which reduced the genetic variation
what do ovule contain
an ovum which is an egg cell that contains female nucleus
how does fertilation occur in plants
- pollen grain grows a pollen tube
- nucleus inside the pollen grain moves down the tube towards ovary
- one both nucleus feat they fuse to form a zygote
what happens to the ovule after fertilliation
develops into a seed
what does the wall of the ovuvle develop into
seed coat, known as testa
what happens to the part of flower surrounding the ovule
develops into a fruit
what is seed dispersal
getting seeds away from the parent plant
what is germination
start of growth in seed
germination process
embryo grows into young seedling
what surrounds the embryo
cotyledons
what do cotyledons do
food reserves that supply the young seedling with food
what happens after seed takings in water
it splits
what does splitting of seed lead too
production of the plumule and radicle
what is asexual reproduction in plants called
runners
what are runners
side branches that have small plantlets at their ends
what happens to runners olnkmlnce they touch soil
they grow roots and new plantlets grow and become independent to parent plant
what is one way to clone plants
taking cuttings
taking cuttings methods
- take cuttings from good parent plants
- section of plant with a new bud is cut off
- cutting can be placed in water until new roots grow or placed directly into soil
- sometimes its placed into rooting powder
- then cuttings are planted
what is rooting powder
powder which contains rooting hormones
