Topic 6

Question 1

What does photosynthesis occur in

Answer 1

Plants and algae

Question 2

What is photosynthesis

Answer 2

Process that plants and algae use to make their own food

Question 3

What energy transfer is photosynthesis

Answer 3

Light to chemical

Question 4

Where is the energy stored in plants

Answer 4

In sugars produced

Question 5

How is light energy absorbed

Answer 5

By chlorophyll in chloroplasts

Question 6

What type of reaction is photosynthesis and why

Answer 6

Endothermic

Absorbs energy from surroundings

Question 7

What are the limiting factors of photosynthesis

Answer 7

Temperature
Light intensity
CO2 concentration

Question 8

What is an independent variable

Answer 8

Something you change

Question 9

What is a dependant variable

Answer 9

What you record

Question 10

What is the control variable

Answer 10

What stays the same

Question 11

What is the practical for photosynthesis

Answer 11

Pondweed

Question 12

How to work out light intensity

Answer 12

1/d^2

Question 13

Unit for light intensity

Answer 13

Arbitrary units

Question 14

Examples of root hair cell adaptations

Answer 14

Long extensions stretch into soil to increase surface area

Therefore - osmosis and diffusion of nutrients

Question 15

Adaptations of xylem cells

Answer 15

Without cytoplasm or cell contents

Therefore more space for water and minerals to go through

Question 16

Adaptations of phloem cell

Answer 16

Use energy for active transport of sucrose around the plant within phloem sieve tubes

Question 17

Transpiration

Answer 17

Loss of water by evaporation from leaves

Question 18

Transpiration stream definition

Answer 18

Movement of water from roots to leaves

Question 19

Transpiration stream description

Answer 19

Water enters through osmosis
Up stem through xylem
Draws water out of xylem
Vapour evaporates through stomata

Question 20

Translocation

Answer 20

Transport of sucrose around plant in phloem

Question 21

Translocation description

Answer 21

Sucrose produced
Needed for growth
Carried in phloem
Dissolved sugars convert to starch in storage organs (eg potato)

Question 22

2 reasons for a leaf to adapt

Answer 22

Photosynthesis and gas exchange

Question 23

Examples of leaf adaptations

Answer 23

• epidermis cells and waxy cuticle transparent
• flat large surface area
• xylem brings water and phloem removes sugar
• stomata
• Internal air spaces for increase surface area

Question 24

Why do stomata close at night

Answer 24

Light is limiting factor

Therefore need to reduce water loss

Question 25

Three environmental factors affecting transpiration

Answer 25

Light intensity Air movement Temperature

Question 26

Practical for rate of transpiration with explanataion

Answer 26

Potometer 1) note position of bubble 2) note position after no of mins 3) distance moved/time

Question 27

Plant adaptation in dry

Answer 27

Cactus Spikes (lose less water) Thick fleshy body store water Large root system

Question 28

Plant adaptation for tropical

Answer 28

Large leaves Climbing plants Drop tips

Question 29

Phototropism

Answer 29

Plant bends towards light

Question 30

Gravotropism

Answer 30

Due to gravity

Question 31

Auxins

Answer 31

Make cells elongate on shaded part of plant | Cause phototropism

Question 32

Selective weed killers

Answer 32

Put on crops and weeds, weeds grow too fast and die so less competition for crops

Question 33

Rooting powder

Answer 33

Contains auxins | Dip cutting of plant into it so it grows more quickly

Question 34

Gibberelins

Answer 34

Decrease seeds Increase size of flower or fruit Stem elongation

Question 35

Seedless fruit

Answer 35

Gibberellins | Spray on fruit for less seeds and more yield

Question 36

What are unripe tomatoes picked

Answer 36

Less damage

Question 37

Why is Ethene put on fruit

Answer 37

Ripen them