Biology 5

Question 1

Producers

Answer 1

Only organisms which can make their own food by photosynthesis are called producers. All food chains start with a producer, which is then eaten by a consumer and so on.

Question 2

what do the arrows represent in the food chain

Answer 2

the arrows represent the flow of energy from producers to consumers

Question 3

why is photosynthesis important

Answer 3

-provides plants with the energy required
-plants are food for us and the meat that we eat
-removes carbon dioxide from the atmosphere
-puts oxygen into the atmosphere

Question 4

how is glucose used by the plant?

Answer 4

-fats and oils for storage
-energy/respiration
-cell wall/cellulose
-proteins/ amino acids
- strach
-growth and repair- combined with nitrates to make proteins

Question 5

factors that increase or decrease the rate of photosynthesis

Answer 5

-CO2 concentration
-lack of water
-temperature
-amount of chlorophyll
-amount of sunlight

Question 6

limiting factor

Answer 6

something present in the environment in such short supply that it restricts life process

Question 7

leaf starch experiment- expected findings

Answer 7

-plants that have been kept in the dark should have less starch than plants in light
-the ones in the dark were unable to carry out photosynthesis and so used their starch stores for energy
-cells without chloroplasts cant carry out photosynthesis and so will use its starch stores for energy. this will mean less starch in the leaf

Question 8

one of the building blocks of chlorophyll

Answer 8

magnesium

Question 9

yellow leaves meaning

Answer 9

a plant is not getting enough magnesium

Question 10

what happens if a plant cant get enough magnesium

Answer 10

the plant wouldnt be able to produce as much sugar fir energy, or build up startch stores. limiting its abilty to grow

Question 11

what do plants need

Answer 11

plants also need nitrates (NO3) in order to make amino acids and chlorophyll.

Question 12

Investigate the necessity for chlorophyll, light and carbon dioxide for photosynthesis,
using appropriate controls

Answer 12

-Chlorophyll’s job in a plant is to absorb light
-The energy from the light causes a chemical reaction that breaks down the molecules of carbon dioxide and water and rearranges them to make the sugar (glucose) and oxygen gas.
-

Question 13

external leaf structure of a dicotyledon leaf (most flower plants)

Answer 13

veins- transport food and water
midrib- acts to strengthen and support the blade
blade- broad flat shape gives a large surface area to capture the most sunlight possible .

Question 14

Stomata

Answer 14

-small pore like openings on surface of a leaf
- more on the underside than the top
-allow water+ oxygen to leave and co2 to leave
-do not absorb water- this is done by the roots

Question 15

leaf and structure (leaf tissues)

Answer 15

-waxy cuitle
-upper edpidermis
-palisade mesophyll
-spongy mesophyll
- vascular bundles
-lower epidermis
-guard cells and stomata

Question 16

palisade mesophyll

Answer 16

-top layer of cells in a leaf
-specially adapted to absorb light and have many chloroplasts for photosynthesis
-blocked shape so many of them can be packed into the top layer of leaf
- they are vertical to maximise surface area exposed to light an maximise light absorption for photosynthesis

Question 17

spongy mesophyll

Answer 17

• not packed tightly which allows carbon dioxide to reach palisade cells for photosynthesis
  -irregular shaped cells with few chloroplasts
• creates air space
  -carbon dioxide in oxygen out
  -large surface area to increase the diffusion of carbon dioxide and oxygen

Question 18

guard cells

Answer 18

surround each stomata, they open and close the stomata

Question 19

stomata

Answer 19

stomata are usually concentrated on the bottom of the leaf to limit water loss

Question 20

waxy cuticle

Answer 20

• the outer surface of a leaf has a thin waxy covering
  -prevents water loss within the leaf by evaporation
  -plants in water don’t need a waxy cuticle because they live in a well watered environment and do not experience water loss.

Question 21

xylem

Answer 21

-transport water and minerals
xylem vessels are involved in the movement of water through a plant from its roots to its leaves
water:
-Is absorbed from the soil through root hair cells
-Is transported through the xylem vessels up the stem to the leaves
-Evaporates from the leaves
-red

Question 22

vascular bundles

Answer 22

-outside is made of large group of closely packed cells could bundle sheath cells
-inside the vascular bundle is tightly packed groups of tubules called xylem and phloem

Question 23

phloem

Answer 23

transport food- sugars
Phloem vessels are involved in translocation. This is the movement of food substances from the stems to growing tissues and storage tissues.
-nitrate is important ion
-green

Question 24

air space

Answer 24

allow movement and exchange of gases spefically oxygen carbon dioxide and water vapour

Question 25

upper epidermis

Answer 25

cells of the upper edimpers are closely packed together it mostly has protective functions in allows light to come in but also prevents water loss in conjunction with the waxy cuticle

Question 26

lower epidermis

Answer 26

has cells closely packed together in order to prevent water loss