Plant Transport Systems Flashcards
What is sexual reproduction
-sexual reproduction involves 2 parents.
-all of the offspring produced are different from each other (variation)
-sexual reproduction is important for introducing variation in a population and enables a species to adapt to changing environmental conditions.
what is asexual reproduction
-asexual reproduction involves only 1 parent and all the offspring produced are identical to the parent (clones)
-asexual reproduction does not produce variation but it allows populations to grow quickly.
what are male plant gametes
male gametes are inside the pollen grains and are produced by the anther of the flower
what are the female plant gametes
female gametes are inside the ovule and are produced by the ovary
what is pollination
pollination involves the transfer of pollen from the anther to the stigma
pollination can be carried out by either wind or insects
describe pollen tube growth
-once the pollen grain lands on the stigma it responds to the presence of sugar there and uses it as an energy source to grow a pollen tube down the female tissues into the ovary.
-As the pollen tube grows out from the pollen grain, the pollen grains nucleus travels down the pollen tube.
describe plant fertilisation
-Fertilisation is the fusion of the nuclei of the two haploid gametes to produce a diploid zygote.
-In plants, fertilisation occurs when the nucleus of a pollen grain joins with the nucleus in the ovule to produce a diploid zygote.
-After fertilisation, the ovary becomes a fruit and the fertilised ovule becomes a seed
what are the three parts of a seed
-food store
-embryo
-seed coat, protects seed contents (food store, embryo) in sold and during animal digestion
what is germination
-germination is the process of the growth of the embryo.
-germination is needed for the embryo within the seed to grow and develop to become a fully grown adult plant
what factors affect germination
- water
-oxygen
-warmth (suitable temperature)
(W.O.W)
what are runners
method of asexual reproduction (spider plants/strawberries)
-plantlet grows at the end of runner
-food is passed along runner from parent to plantlet until it had developed its own leaves and roots and can produce its own food by photosynthesis.
-runner died and allows plantlet to develop into an independent adult plant.
what are tubers
method of asexual reproduction (potatoes)
-the parent plant makes food in its leaves and sends this down to underground stems where they become swollen tubers.
swhat are bulbs
method of asexual reproduction (onions)
-underground food stores formed from swollen leaf bases
-new bulbs tend to form around the base of the parent bulb
-these are called daughter bulb and can be separated from the parent and planted in new sites
what are advantages of asexual and sexual reproduction
asexual
-all offspring are identical to their parents, passes on favourable characteristics to offspring.
-allows population to grow quickly, offspring provided with food supply from their parent so they grow faster.
sexual
-all offspring are different. Introduces variations. enables species to adapt to changes in environmental conditions.
what are disadvantages of asexual and sexual reproduction
asexual
-no variation introduced as all offspring are identical to parent plant.
-off spring are in competition with their parent plant for resources,
sexual
-desirable characteristics may not be passed to offspring
what is artificial propagation
when a plant lacks its own method of asexual reproduction then man can try this method. It involves cloning the original plant using unnatural methods that humans have invented.