Organisation in plants

Question 1

Function of waxy cuticle

Answer 1

Makes leaf waterproof

Question 2

Function of upper epidermis

Answer 2

Protects against water loss

Question 3

Characteristics of upper epidermis

Answer 3

Single layer of cells
Transparent to allow light to pass through

Question 4

Adaptions of palisade mesophyll

Answer 4

Tightly packed cells with many chloroplasts to absorb as much light as possible for photosynthesis

Question 5

Adaptions of spongy mesophyll

Answer 5

Air spaces increase SA to allow gases to diffuse quickly

Question 6

Function of stomata

Answer 6

Tiny openings on lower surface of leaf to allow gases to move in and out of

Question 7

Functions of guard cells

Answer 7

Control opening and closing of stomata

Question 8

What do stomata control

Answer 8

Gas exchange and water loss

Question 9

How do stomata control gas exchange and water loss

Answer 9

Allowing diffusing of carbon dioxide into plant for photosynthesis
Allowing diffusion of oxygen out of plant

Question 10

How to guard cells become turgid

Answer 10

When plants have lots of water

Question 11

What is transpiration

Answer 11

Movement of water from roots to the leaves through the xylem

Question 12

What is the purpose of transpiration

Answer 12

Provide water to keep cells turgid
Provide water for photosynthesis
Transport mineral ions to leaves

Question 13

Function of xylem

Answer 13

Transport water and mineral ions from roots to rest of plant

Question 14

3 adaptations of xylem

Answer 14

Made of dead cells
No end wall between cells
Walls strengthened by chemical called lignin to withstand water pressure

Question 15

What is purpose of translocation

Answer 15

Transport dissolved sugars from leaves to other parts of plant for respiration, growth, storage

Question 16

Function of phloem

Answer 16

Transport dissolved sugars from leaves to rest of plant

Question 17

4 factors that affect rate of transpiration

Answer 17

Temp, light intensity, humidity, wind speed

Question 18

What effect does temp have on rate of transpiration and why

Answer 18

Higher temps increase rate because water evaporates faster

Question 19

What effect does humidity have on rate of transpiration and why

Answer 19

Higher levels of humidity decrease rate of transpiration because there is a steeper concentration gradient of water molecules between the air and leaf

Question 20

How does the wind speed effect the rate of transpiration and why

Answer 20

More wind increases rate of transpiration because wind removes water vapour quickly maintaining the steep concentration gradient

Question 21

How does light intensity effect the rate of transpiration and why

Answer 21

Higher light intensity increases rate of transpiration because the stomata will open wider to let more carbon dioxide in for photosynthesis

Question 22

Why do root hair cells have a large SA

Answer 22

To increase absorption of water and mineral ions into root

Question 23

Why do roots hair cells have lots of mitochondria

Answer 23

To transfer a lot of energy for intake of mineral ions by active transport