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.
what are cuttings
method of artificial propagation.
-small section from parent plant is removed and allowed to develop its own roots to develop into an independent plant.
-new plant will be identical to parent plant
what is grafting
method of artificial propagation.
-wedge of stem from one plant if forced into a sit in another.
-new plant with characteristics from both grafts
what are plant tissue cultures
method of artificial propagation
-cells removed from root tip
-root cells transferred to nutrient jelly to multiply
-they will multiply into a bundle of cells which begin to specialise into different cells (e.g roots/shoots) which eventually form a new plant
-new plant will be identical to parent plant
what are advantages of artificial propagation (cuttings, grafting, tissue culture)
desirable characteristics are passed on to the offspring (clones)
conservation-we can save some rare species
how do plants make food and what does this involve
photosynthesis - plants convert light energy from the sum into chemical energy in food, they are producers
what does plant food supply
food for organisms higher up in the food chain
why are plants grown?
plants are grown to provide:
1) Food, e.h wheat for bread
2) Fuel, wood or biofuel (sugarcane)
3) raw materials
4)medicines, morphine/codeine
5)aesthetic reasons
6)habitats for other animals
why do would we need to increase plant yield
to make food food for an increasing human population - allows to harvest more plants per unit area of land
what are fertilisers
allow us to increase crop yield
-fertilisers provide chemicals such as nitrates which increase crop yield.
-nitrates are absorbed into plants through the soil.
-nitrates are used to produce amino acids which are synthesised into plant proteins.
-animals consume plants or other animals to obtain amino acids for protein synthesis.
-fertilisers can be used to increase soil nitrate content.
what are methods of increasing plant yield.
1) Fertilisers
2)Pesticides
-plants and animals which reduce crop yield can be killed by pesticides
3) Genetically Modified Crops
-GM crops can be used to reduce the use of fertilisers and increase crop yield.
4) Pharming
-means of genetically modifying plants to produce medicinal products
what are the three plant organs
1) roots
2)stems
3)leaves
where does photosynthesis take place?
Leaves, inside chloroplasts where chlorophyll is stored, chloroplasts are in palisade and spongy mesophyll as well as in guard cells.
what are the 7 types of cell in a leaf
1) upper epidermis
2)palisade mesophyll
3) spongy mesopyll
4) vein (consisting of xylem and phloem)
5) stomata
6) guard cell
7)lower epidermis
what is the word equation for photosynthesis
sunlight
Carbon dioxide + Water —-> Glucose + Oxygen
chlorophyll
where do plants get CO2 and water for photosynthesis
co2 diffuses into the leaf through the stomata
water enters the plant through the root hairs
what are and what do xylem vessels do
-Xylem vessels are dead, hollow tubes
-They transport water and minerals upwards from roots to leaves for photosynthesis.
-They contain lignin, which allows the plant to withstand pressure changes as water moves through the plant
what are the two types of plant vessels
xylem and phloem
what are and what do ploem do
-phloem are are considered to be living as they have companion cells.
-sugar is transported up and down the plant in the living phloem.
-phloem have sieve plates and associated companion cells.
what is transpiration
transpiration is the process of water moving through a plant and its evaporation through the stomata
what are the 3 stages of transpiration
1) water enters a plant through the root hairs from the soil by a process of osmosis (water moves from a region higher water concentration in the soil to a region of LWC in the root hair)
2)Water then travels upwards through the xylem vessels.
3) The underside of leaves have small pores called Stomata. Water evaporates through the stomata into the air which creates a sucking action to draw the water upwards (against gravity).
This moves water from the roots to the top of the plant, without using energy.
what piece of equipment measures the rate of transpiration?
a potometer
what factors affect the rate of transpiration
increase in wind speed - increased rate of transpiration.
increase in temperature - increased transpiration.
increase in surface area of leaf (more stomata) - increased transpiration
increased humidity - decrease transpiration
what are stomata
-small pores on the underside of leaves
-they allow for the entry of C02 for photosynthesis and the loss of water by evaporation during transpiration, and the loss of oxygen
-they are open during the day and closed at nigt
what are guard cells
-two sausage shaped guard cells surround each stomata
-they control the opening and closing of the stomata.
-they contain chloroplasts, so the also photosynthesise
