Photosynthesis

Question 1

What is photosynthesis

Answer 1

An endothermic process used by plants to convert carbon dioxide and water into glucose and oxygen using energy in sunlight.

Question 2

Word equation for photosynthesis

Answer 2

water + carbon dioxide → glucose + oxygen

Question 3

Symbol equation for photosynthesis

Answer 3

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

Question 4

What are chloroplast

Answer 4

An organelle that contains chlorophyll and in which photosynthesis takes place.

Question 5

What are chlorophyll

Answer 5

Green pigment in plants that absorbs light energy used to carry out photosynthesis.

Question 6

Endothermic

Answer 6

(absorbs heat)

A chemical reaction that requires a net input of energy

Question 7

Adaptations of leaves for photosynthesis

Answer 7

Broad, thin, veins, cells packed with chloroplasts, waxy cuticle, stomata.

Question 8

What are stomata?

Answer 8

Small openings on the underside of a leaf through which oxygen and carbon dioxide can move.

Question 9

What are guard cells?

Answer 9

Cells that control the opening and closing of the stomata.

Question 10

What are palisade mesophyll

Answer 10

Layer of cells packed with chloroplasts, where most photosynthesis occurs.

Question 11

What are spongy mesophyll?

Answer 11

Layer of irregularly shaped cells with air spaces to allow gases to diffuse in and out of cells.

Question 12

What are waxy cuticle?

Answer 12

A waterproof barrier that protects the leaf and prevents water loss.

Question 13

What is gas exchange?

Answer 13

The transfer of gases between an organism and its environment

Question 14

What is vascular bundle

Answer 14

Clusters of xylem and phloem tissue in stems.

Question 15

What is Xylem

Answer 15

Tissue that transports water and dissolved minerals in vascular plants.

Question 16

What are phloem?

Answer 16

Tissue that transports sugars in vascular plants.

Question 17

Factors that affect the rate of photosynthesis

Answer 17

Light intensity
Temperature
Carbon dioxide
Chlorophyll

Question 18

What is meant by ‘Limiting Factor’

Answer 18

A factor in short supply that prevents the rate of reaction from increasing.

Question 19

Why carbon dioxide can be a limiting factor

Answer 19

Carbon dioxide is a raw material for photosynthesis.

Question 20

Why light intensity can be a limiting factor

Answer 20

Light provides the energy that is needed for photosynthesis.

Question 21

Why temperature is a limiting factor

Answer 21

If the temperature is too low the enzymes work slowly. If the temperature is too high the enzymes are denatured and do not work.

Question 22

Why chlorophyll is a limiting factor

Answer 22

Chlorophyll is needed to absorb the light energy used to carry out photosynthesis

Question 23

Importance of limiting factors

Answer 23

Farmers and commercial growers can artificially create the ideal environment to grow plants.

Question 24

Five uses of glucose

Answer 24

For respiration
Making cellulose
Making amino acids
Stored as oils or fats
Stored as starch

Question 25

What is Cellulose

Answer 25

A polymer made of glucose used to build plant cell walls

Question 26

What is starch?

Answer 26

An insoluble polymer made of glucose that is used for storage.

Question 27

What is respiration?

Answer 27

The chemical process that takes place in cells and releases energy from glucose in the presence of oxygen.

Question 28

What are Amino Acids

Answer 28

The building blocks of proteins. Formed by combining glucose with nitrate ions.

Question 29

What are fats and oils

Answer 29

Storage compounds found in seeds.

Question 30

What is the concentration gradient?

Answer 30

A difference in concentration between two areas next to each other

Question 31

What is diffusion?

Answer 31

The net movement of particles from an area of high concentration to an area of lower concentration.

Question 32

What is Passive Transport?

Answer 32

Happens due to the random motion of particles. No energy is required.

Question 33

What is osmosis?

Answer 33

The movement of water molecules across a partially permeable membrane from a a region of higher water concentration to a region of lower water concentration.

Question 34

What is active transport?

Answer 34

The movement of molecules from a region of low concentration to a region of high concentration. This requires energy.

Question 35

What is a semi-permeable membrane?

Answer 35

A membrane that allows only certain molecules to pass through.

Question 36

Adaptation of root hair cells

Answer 36

A large surface area for absorption.

Question 37

What is Rose black spot

Answer 37

A parasitic fungus that causes black spot on roses.

Question 38

What is Tobacco Mosaic Virus?

Answer 38

A virus that affects plants. It causes stunted growth and causes leaves to discolour, curl and have yellow streaks or spots.

Question 39

What is chlorosis?

Answer 39

Yellow leaves caused by a lack of magnesium which is needed to produce chlorophyll.

Question 40

What are physical defences on plants

Answer 40

Layers of dead cells around stems
Tough waxy leaf cuticles
Cellulose cell walls

Question 41

How is rose black spot treated?

Answer 41

Removing infected dropped leaves and burning them.
Pruning shoots in the spring.
Treating infections with fungicides.

Question 42

How is rose black spot transmitted?

Answer 42

The fungus produces spores which are released in wet, humid conditions.

Question 43

How does black spot fungus affect the growth of roses?

Answer 43

Damaged leaves cannot photosynthesise efficiently.

Question 44

How can plant diseases be identified?

Answer 44

Stunted growth.
Spots on leaves.
Areas of decay.
Discolouration.
Presence of pests.