plants n stuff

Question 1

process of photosynthesis with some depth

Answer 1

carbon dioxide - from atmosphere diffuses into leaves through stomata
water - absorbed by osmosis from the soil by roots
light energy - absorbed by chloroplasts

oxygen - released to atmosphere by diffusion from leaves via stomata
glucose - produced and uses by plant, transported by phloem to cells

Question 2

photosynthesis equation

Answer 2

6CO2 + 6H2O -> C6H12O6 + 6O2
endothermic

Question 3

uses of glucose from photosynthesis

Answer 3

-respiration to release energy
-converted to starch for storage
-used to produce lipids for storage
used to produce cellulose cell walls
used to produce amino acids (with nitrates) for protein synthesis

Question 4

how does light intensity affect rate of photosynthesis

Answer 4

increasing increases rate of photosynthesis

Question 5

how does carbon dioxide affect rate of photosynthesis

Answer 5

increasing increases rate of photosynthesis

Question 6

how does temperature affect rate of photosynthesis

Answer 6

increasing increases rate of photosynthesis up to the optimum then rapidly decreases as enzymes denature

Question 7

how does amount of chlorophyll affect rate of photosynthesis

Answer 7

more chlorophyll means more light energy absorbed increasing rate of photosynthesis

Question 8

at low light intensities, ____________________________ have very little effect on the rate of photosynthesis

Answer 8

temperature and co2

Question 9

co2 conc has a greater effect on rate than

Answer 9

temperature

Question 10

how do greenhouses control photosynthesis and help increase yield

Answer 10

light intensity increased with glass windows and extra lighting on cloudy days. red and blue leds also used

temperature is controlled with automatic windows, fans and heaters to maintain optimum throughout year

carbon dioxide conce can be pumped in from burners / engines or nearby factories or from fungi respiration

water and mineral ions also kept at an optimum

cost balanced with these to get best yield for profit worth!!!!!!!!!!!

Question 11

photosynthesis practical

Answer 11

independent variables:
change light intensity by moving lamp closer, using a heat shield
use lights of different wavelengths using coloured leds or filters
use a waterbath at different temps
use a different mass of bicarbonate of soda to alter co2 concentration

dependant variable:
measure number of bubbles of 02 produced in a set time
OR
use gas syringe to collect and measure volume of o2 produced in a certain amount of time

Question 12

inverse square law

Answer 12

as the distance from a lamp increases, the light intensity decreases as the photons in the light have to spread out over a larger area
light intensity is directly proportional to 1/distance¬2

Question 13

organisation (order of size of stuff??????)

Answer 13

atom
molecule
cell
tissue (a group of similar cells working together to carry out a function)
organ (a group of tissues working together)
organ system
organism

Question 14

root hair cells

Answer 14

absorb water and minerals from soil
large surface area
lots of mitochondria for lots of energy for active transport

Question 15

xylem

Answer 15

lignified dead cells form hollow tubes to transport water + mineral ions

unidirectional

thick cell wall on outside

cells have no walls between them

Question 16

phloem

Answer 16

living cells that use energy to transport sugars from photosynthesis around plant

TRANSLOCATION

Question 17

transpiration

Answer 17

the evaporation of water vapour through the stomata of leaves
flow of water from roots to leaves is the transpiration stream
water vapour evaporates through stomata

Question 18

how do stomata open

Answer 18

when they open for gas exchange, water evaporates from the spongy mesophyll cells turning them from flaccid and shut to turgid and open

Question 19

how do water levels remain stable in plants

Answer 19

as water is lost through leaves, it is replaced from the xylem.
a continuous column of water drawn up from roots due to the cohesion of water molecules which form hydrogen bonds

Question 20

what can be used to measure rate of diffusion

Answer 20

potometer

Question 21

parts of a potometer

Answer 21

a shoot from a plant which water can evaporate from
an unbroken column of water consisting of
joins to a capillary tube - contains an air bubble
move air bubble to start of scale with the tap and reservoir
scale allows us to measure distance the air bubble moves as water evaporated from leaves and more is sucked up

Question 22

air affecting transpiration

Answer 22

as wind increases
rate of evaporation is increased

Question 23

light affecting transpiration

Answer 23

when increased increases stomata opening so increases transpiration rate

Question 24

temperature affecting transpiration

Answer 24

increases rate of evaporation when increases

Question 25

humidity affecting transpiration

Answer 25

DECREASES the rate of transpiration when humidity is increased

Question 26

a leaf is a plant ______________

Answer 26

organ! made up of different tissue layers that make it adapted for photosynthesis and gas exchange

Question 27

palisade mesophyll

Answer 27

layer of cells containing lots of chloroplasts to absorb light for photosynthesis the like long ovular layer like 2nd layer

Question 28

upper epidermis

Answer 28

layer of transparent tissue to let light through to the palisade level the square shaped things

Question 29

spongy mesophyll cells

Answer 29

open tissue with lots of air spaces creating a large surface area for gas exchange to take place spread out in middle

Question 30

lower epidermis

Answer 30

contains stomata allowing gases and water vapour to enter/exit the leaf

Question 31

guard cells

Answer 31

control the opening and closing of the stomata. must balance the need to open for gas exchange with the prevention of water loss through transpiration

Question 32

adaptations to reduce water loss in xerophytes (cacti etc)

Answer 32

thick waxy cuticle waterproofs leaves and stems to reduce evaporation of water small leaf surface area/needles reduces surface area for water evap and the number of stomata reduced number of stomata extensive root systems (wide and shallow or very deep) maximises water uptake increasing chance of contact with water swollen leaves or stems to store all collected water

Question 33

phototropism

Answer 33

positive in shoots bend towards light more auxins on shaded side causes increased cell number / growth negative in roots bend away from light more auxins on shaded side INHIBITS growth

Question 34

investigate phototropism

Answer 34

cover diff parts of shoot with foil

Question 35

geotropism

Answer 35

negative in shoots grow against the pull of gravity to find light auxins move to lower side causing elongation to shoots bend upwards positive in roots grow with gravity auxin smove to lower side inhibiting cell growth so upper side grwows more

Question 36

investigate geotropism

Answer 36

exclude light grow in diff angles record direction of shoot growth

Question 37

use of auxins for humans

Answer 37

as weed killers (causes plants to grow too fast and collapse) as rooting powders for cuttings promote growth in tissue culture

Question 38

use of ethene for humans

Answer 38

in plants, controls cell division and fruit ripening humans use it in food industry to control ripening to reduce damage from transport and storage

Question 39

use of gibberellins for humans

Answer 39

initiates seed germination can be used to end seed dormancy promote flowering increase fruit size