Biology unit 6

Question 1

Definition of photosynthesis

Answer 1

the process by which plants manufacture carbohydrates from raw materials using energy from light

Question 2

Word and symbol equation of photosynthesis

Answer 2

Carbon dioxide + water ➡️ glucose + oxygen

Question 3

Chlorophyll

Answer 3

Chlorophyll is the protein found within chlorophlasts that catalyses the reaction. It is also what causes plants to be green.

Question 4

1 uses of glucose in plants

Answer 4

Glucose is commonly stored in plants as starch (long chains of glucose)

Question 5

2 uses of glucose in plants

Answer 5

Glucose can be used in cellulose to build cell walls

Question 6

3 uses of glucose in plants

Answer 6

Glucose can be used for respiration

Question 7

4 uses of glucose in plants

Answer 7

Glucose can be converted and transported through phloem vessels from SOURCE to SINK

Question 8

5 uses of glucose in plants

Answer 8

Glucose can be converted to nectar and used to attract pollinators

Question 9

Leaf adaptations

Answer 9

Large surface area
Very thin- air diffusion

Question 10

Parts of the leaf - guard cells

Answer 10

Guard cells - open and close stomata

Question 11

Parts of the leaf - waxy cuticle

Answer 11

Waxy cuticle - allows light to pass whilst protecting leaf surface

Question 12

Parts of the leaf - epidermal cells

Answer 12

Offers protection but thin to allow light through

Question 13

Palisade cells

Answer 13

Contain many chloroplast
Packed tightly together
Large surface area
Large vacuole pushes chloroplast to edges of cell
Thin cell walls to aid gaseous exchange

Question 14

Sponges mesophyll

Answer 14

Irregular shaped
Fewer chloroplasts
Smaller than palisade cells
Spaced out with air pockets in between

Question 15

Vascular bundle

Answer 15

Xylem - carries water up the plant
Phloem - carries nutrients all around the plant

Question 16

Definition of limiting factor

Answer 16

A limiting factor is something that is in short supply that restricts a process

Question 17

Limiting factors of photosynthesis

Answer 17

When a process depends on two or more factors (variables), the rate of that process is determined by the factor which is in shortest supply ( aka bottleneck)

Question 18

Limiting factors of photosynthesis

Answer 18

Light intensity
Carbon dioxide concentration
Temperature

Question 19

Effect of light intensity

Answer 19

The rate of photosynthesis increase with light intensity
When the intensity of light increases to a certain point, photosynthesis cannot go any faster

The actual max varies depending on the plant 🌱 type

Question 20

Effect of carbon dioxide concentration

Answer 20

Increasing the carbon dioxide concentration, increases rate of photosynthesis
But, there is a max rate, where adding more co2 will have no effect anymore

Question 21

Effect of temperature

Answer 21

Too much heat damage enzymes and causes them to denature
Too much heat also evaporates water out of leaves and forces stomata to close
Too little heat can reduce enzymes reaction rate by reducing number of collisions between the enzyme’s active site and substrate

Question 22

Magnesium deficient plants

Answer 22

Magnesium is required for chlorophyll
Yellowing between the veins of leaves (aka chlorosis) due to lack of chlorophyll production

Question 23

Nitrate deficient plants

Answer 23

Stunted growth
Leaves (usually near growing tip) start to turn yellow

Question 24

Ratio of photosynthesis to respiration

Answer 24

The ratio of photosynthesis to respiration in plants changes over the day cycle
Plants are constantly respirating and releasing carbon dioxide
Plants only photosynthesise during the day when sunlight is available taking in carbon.

Question 25

Net carbon dioxide day vs night

Answer 25

During the day plants photosynthesise faster than they respire, resulting in a net intake of carbon dioxide
During night plants respire more than they photosynthesis, resulting in a net release of carbon dioxide

Question 26

Hydrogen carbonate indicator

Answer 26

Hydrogen carbonate
indicator is a pH indicator
that changes colour
depending on the pH of a
solution
Carbon dioxide is acidic.
Higher carbon dioxide
concentration = more
acidic