Topic 9

Question 1

What are autotrophs

Answer 1

Plants which make their own food via photosynthesis

Question 2

Heterotrophs

Answer 2

Organisms which feed on others for food

Question 3

what is the process of photosynthesis

Answer 3

co2 + water -> oxygen, glucose, water

Question 4

What colour of light does chlorophyll absorb

Answer 4

red and blue-violet light
(green light is reflected thus giving leaves their colour)

Question 5

What are the external parts of the leaves and their functions:

Answer 5

Lamina: large surface area for greatest absorbtion of sunlight and allow for rapid diffusion of carbon dioxide
Leaf stalk: Positions the lamina for (stated above)
Network of veins: transport food, water, mineral salts

Question 6

What are the internal parts of the leaf(not function yet)

Answer 6

Cuticle
Upper/lower epidermis
palisade mesophyll
vascular bundle
spongy mesophyll

Question 7

Function of the cuticle

Answer 7

waxy layer above the epidermis to reduce excessive water loss
Transparent to allow light to pass through

Question 8

Function of palisade mesophyll

Answer 8

a few layers of closely packed cells which are long and cylindrical
Contain numerous chloroplasts

Question 9

Function of vascular bundle

Answer 9

contain xylem and phloem which transport water and food respectively

Question 10

Function of spongy mesophyll

Answer 10

irregularly shaped cells, numerous large intercellular air spaces to allow for rapid diffusion of gases, less chloroplasts than palisade mesophyll

Question 11

Function of lower epidermis

Answer 11

single layer of closely packed cells, with minute openings called stomata to allow co2 to enter and oxygen to exit

Question 12

Function of gaurd cells

Answer 12

Surrounds stomata, controls the size of stomata

Question 13

What happens to the gaurd cells in the presence of light

Answer 13

gaurd cells manufacture glucose by photosynthesis, lowering water potential, water from adjacent cells enter gaurd cells via osmosis, gaurd cells swell and become turgid, curving and opening the stomata

Question 14

What happens to gaurd cells in the absence of light

Answer 14

glucose is used up or stored as starch, increasing water potential of the cells, water exits the cell via osmosis, the cell becomes flaccid and stomata closes

Question 15

How does co2 enter the leaf

Answer 15

co2 is rapidly used up during photosynthesis, concentration of co2 in leaf is lower than surrounding air, co2 diffuses into the leaf through the stomata, Co2 is dissolved into film of water around mesophyll cells and then diffuses into the cell

Question 16

What are the 5 fates of glucose

Answer 16

Top 5 anime betrayals

Question 17

What are the 5 fates of glucose

Answer 17

Broken down during cellular respiration to release energy

Form cellulose cell wall

Excess glucose temporarily stored as starch

Form amino acids and fats

Converted into sucrose and transported to storage organs