Plants and their functions

Question 1

write the word and symbol equations for photosynthesis

Answer 1

water + carbon dioxide -> glucose + oxygen

H2O + CO2 -> C6H12O6 + O2

Question 2

why does each food chain need to start with the green plant or algae

Answer 2

so that the green plant or algae can produce glucose from the suns energy and therefore biomass

Question 3

which part of a plant cell absorbs light to allow photosynthesis to occur and what is the chemical called which is inside of this organelle

Answer 3

chloroplasts absorb the sunlight and the chlorophyll is the chemical inside of them

Question 4

what type of reaction is photosynthesis and what does this mean

Answer 4

endothermic reaction as energy is taken in during the reaction

Question 5

what are the three limiting factors of photosynthesis

Answer 5

light intensity, temperature and carbon dioxide concentration

Question 6

what does a limiting factor mean

Answer 6

they can stop photosynthesis from happening any faster

Question 7

describe what happens to the rate of photosynthesis if: a. light intensity increases, b. carbon dioxide concentration increases, c. temperature increases

Answer 7

a. photosynthesis gets faster as light intensity increases, b. photosynthesis gets faster as carbon dioxide concentration increases, c. photosynthesis gets faster as temperature increases but only until a certain temperature, if it is too hot it slows down and can stop

Question 8

what is the limiting factor on a light intensity limiting factors graph when light intensity and rate of photosynthesis are no longer directly proportional

Answer 8

even carbon dioxide or temperature

Question 9

how was your describe the relationship between light intensity and rate of photosynthesis, what about distance from the light source and rate of photosynthesis

Answer 9

light intensity is directly proportional to the rate of photosynthesis, distance from the light source is inversely portional to the rate of photosynthesis

Question 10

how are root hair cells specialised for their job

Answer 10

they have a very large surface area to allow maximum absorption of water as each root hair cell is covered in millions of microscopic hairs

Question 11

which process is water absorbed into plant roots, which process of mineral ions absorbed by

Answer 11

water is absorbed by osmosis while mineral ions are absorbed by active transport

Question 12

are phloem and xylem cells dead or alive

Answer 12

phloem cells are alive while xylem cells are dead

Question 13

what do phloem cells transport and how

Answer 13

phloem cells transport food substances, like sucrose, from the leaf, where it’s made, to the rest of the plant for use or storage, this is called translocation

Question 14

what does xylem cells transport and how

Answer 14

they transport water and mineral ions from the root to the stems and the leaves, this movement is called the transpiration stream

Question 15

describe the structure of phloem cells

Answer 15

columns of elongated cells with end walls containing small pores to allow substances to be transported through

Question 16

describe the structure of xylem cells

Answer 16

tubular cell structure is made of dead cells with no end walls and a hole down the middle, they are strengthened with a material called lignin

Question 17

through which two processes is water lost from the surface of the leaf in transpiration

Answer 17

evaporation and diffusion

Question 18

why does transpiration cause the water to move up through a plant

Answer 18

The loss of water from the leaf causes of reduced concentration of water in the leaf some more water is drawn up through the xylem cells to replace it

Question 19

what do we call the constant flow of water from the roots and up to the leaves

Answer 19

transpiration stream

Question 20

what is also carried along in the transpiration stream apart from water

Answer 20

mineral ions

Question 21

what do we call the tiny pores in the surface of a plant and where are most of these found

Answer 21

stomata found mostly on the underside of the surface of a leaf

Question 22

what is the purpose of a stomata

Answer 22

they allow oxygen and carbon dioxide to enter and leave through diffusion, water vapour also escapes during transpiration

Question 23

explain why water leaves the stomata by diffusion

Answer 23

water leaves the stomata as it goes from an area of high concentration inside the leaf to an area of low concentration outside

Question 24

how do guard cells cause the stomata to open

Answer 24

guard cells surround the stomata, when the guard cells are full of water they change shape causing the stomata to open

Question 25

how do guard cells cause the stomata to close

Answer 25

guard cells surround the stomata, when the guard cells are low in water they change shape causing the stoma to close

Question 26

how does sucrose get transported around the plant

Answer 26

sucrose is translocated in the sieve tubes of phloem tissue, each sieve tube is connected to the neighbours by holes which sucrose flows through

Question 27

which type of cells pump sucrose into sieve cells

Answer 27

companion cells

Question 28

why does pumping sucrose into sieve cells cause sucrose to move

Answer 28

it increases the pressure of where it is pumped into causing the solution to flow up into growing shoots or down into storage organs

Question 29

name three factors which affect the rate of transpiration

Answer 29

light intensity, temperature, humidity, air movement

Question 30

explain why transpiration levels will be higher on a windy day

Answer 30

the wind removes water particles from the air surrounding the leaf so there is a lower concentration of water around the leaf

Question 31

explain why higher temperatures will increase the rate of transpiration

Answer 31

particles will move around faster and therefore diffuse faster

Question 32

explain why increased light intensity will increase the rate of transpiration

Answer 32

increased life intensity means increased levels of photosynthesis, this will mean stomata are open wider therefore more water can leave the leaf through transpiration

Question 33

what is the equation for estimating transpiration rate using a potometer

Answer 33

distance moved by the bubble/ time taken