Sb6

Question 1

What is algae

Answer 1

A protist

Question 2

Biomass

Answer 2

The materials in an organism

Question 3

Why are plants producers in a food chain

Answer 3

Because they produce their own biomass and produce food for the rest of life on Earth

Question 4

Photosynthesis equation

Answer 4

Carbon dioxide + water = glucose + oxygen

Question 5

Where does photosynthesis occur

Answer 5

It occurs in chloroplast because they contain a green substance called chlorophyll that traps energy transferred by light

Question 6

Is photosynthesis endothermic or exothermic

Answer 6

Endothermic

Question 7

Why is photosynthesis an endothermic reaction

Answer 7

Because the products of photosynthesis have more energy than the reactants since energy enters by transfer of sunlight

Question 8

What happens to the glucose after it’s made by photosynthesis

Answer 8

The glucose molecules linked together to form a polymer called starch. Which stays in the chloroplast until photosynthesis stops

Question 9

What happens to the starch after photosynthesis stops

Answer 9

The starch is broken down into simpler substances and is moved into the cytoplasm and is used to make sucrose which is transported around the plant

Question 10

What can sucrose be used to make

Answer 10

Starch in a storage organ
Other molecules like cellulose lipids or proteins
Glucose for respiration

Question 11

Adaptations of leaves

Answer 11

They are broad and flat which gives them a large surface area which allows rate of reaction to be quicker

Question 12

Palisade cells adaptations

Answer 12

They are near the top of the leaf and awful of chloroplasts so they can absorb a great deal of light

Question 13

How are leaves adapted for carbon dioxide needs

Answer 13

They contain pores called stomata which allow carbon dioxide to diffuse into the leaf. They are opened and closed by guard cells.

Question 14

How are guard cells specialised

Answer 14

In light water flows into guard cells making them rigid which opens the stomata. At night water flows out of the guard cells which lose their rigidity and the stomata shuts shuts

Question 15

Why does photosynthesis happen slower at the top of a mountain

Answer 15

Because there are reduced concentrations of air molecules at the top of a mountain which reduces the rate of photosynthesis because the enzymes that help with photosynthesis work better at warmer temperatures so they don’t happen as quickly

Question 16

Limiting factors

Answer 16

A factor that prevents a rate increasing as a limiting factor. In photosynthesis the limiting factors are
Carbon dioxide concentration
Temperature
Light intensity

Question 17

Inverse square Law

Answer 17

Lnew = Lorig xD^2orig/ d2 new

Question 18

Why do plants absorb water

Answer 18

To carry dissolved mineral ions
Keep cells rigid to reduce silting
Cools the leaves
Photosynthesis

Question 19

Root hair cells adaptations

Answer 19

The root hairs provide a large surface area so water and mineral ions can be quickly absorbed

Have thin walls for quicker diffusion

Question 20

What is used to transport mineral salts

Answer 20

Through active transport which uses carrier proteins

Question 21

Transpiration

Answer 21

Flow of water into a root, up the stem and out of the leaves

Question 22

Xylem process

Answer 22

Xylem vessels form small pipes from the roots to the leaves
The vessels have an unbroken chain of water because there are weak attraction forces between the molecules
It is kept going because the water diffuses out of the lead and more water evaporates fro the xylem inside the leaf

Question 23

Factors that increase the rate of transpiration

Answer 23

Wind and low humidity means there’s less water outside so there’s a higher concentration gradient so transpiration is faster

Higher temperatures mean particles diffuse faster out of the leaves
Greater light intensity means stomata are wider so more transpiration

Question 24

Xylem adaptations

Answer 24

They have a long empty vessel because they die and their top and bottom cell walls disintegrate this means water can move more easily
They have hard rings on lignin so the water pressure doesn’t burst them

Question 25

Translocation

Answer 25

Transportation of sucrose

Question 26

How do phloem do translocation?

Answer 26

Sucrose is transported in the sieve tubes of phloem tissue
Each sieve cell is connected by holes and sucrose solution flows through this
Companion cells pump sucrose into and out of the sieve cells. When it is being pumped, the pressure increases so sucrose flows up to shoots or down to storage organs

Question 27

Epidermis cells

Answer 27

Form the outside of the leaf, hold the leaf tkfehter and protect cells inside
They are transparent so light can pass through them easily
Produce a waterproof waxy cuticle so water loss is prevented

Cuticles stop microorganisms from getting in

Question 28

Adaptations for cold places to stop water loss

Answer 28

Deciduous trees lose their leaves
Pine trees have needle leaves which have a smaller surface area, which means less water loss
Conifers shape means they can withstand high winds
They have stomata in small pits so water vapid collects because there’s less exposure to reduces the rate of transpiration

Question 29

Adaptations for hot weather

Answer 29

Thick cuticle to reduced water loss
Stomata open at night so carbon dioxide is taken in at night

Question 30

Stimulus

Answer 30

Change in the environment causes a response in the organism

Question 31

Phototropism

Answer 31

Phototropism is response to a stimulus of lights. Plants move towards the light so they are positively phototropic. When a shoot detects light coming from One Direction the auxins which are plant hormones move to the shaded side of the shoot so the shaded site elongates more which means that that shoot grows in the direction of the light

Question 32

Gravitropism

Answer 32

 auxins are also found in a root tips. In the roots auxin causes cells to stop elongating and this causes grow towards the direction of gravity.

This is useful because it helps the roots to anchor a plan in place and to reach the water underground. In shoots they grow upwards so the oxygen is pulled down and therefore the shoot becomes longer. In roots they grow downwards so the auxins are pulled upwards which stops the cell elongating

Question 33

Gibberellins in bananas

Answer 33

Gibberellins of plant hormone that helps seeds to germinate and grow roots and shoots. Ethan gas is used to help fruits ripen. So for example bananas will be picked on right so they can be shipped and then when the time is right they use Ethan to rapidly ripe in the banana so they’re ready for supermarkets

Question 34

Selective weed killer is

Answer 34

These have artificial auxins in them to make the plants grow quickly which kills them. Selective weed killer is target plants with broad leaves like dandelions and weeds but not those with narrow leaves like wheat and grass so they can kill the weeds but don’t affect the crop

Question 35

Auxins in rooting powders

Answer 35

Auctions in rooting powder is cause plant cuttings to develop a route to quickly. This means large numbers of identical plants can be produced quickly

Question 36

Gibberellin uses

Answer 36

Gibberellins are naturally released to start germination. An excess use of gibberellins can make seeds germinate without periods of darkness. Gibberellins can cause fruits to be produced without seeds and they can be used to make a bigger fruits

Question 37

Photoperiodism

Answer 37

The response of an organism to the number of daylight hours in a day. This means some plants will flower at certain times but gibberellins can override this to make them grow quicker