Leaves

Question 1

What are the functions of a leaf?

Answer 1

Photosynthesis, transpiration and gaseous exchange

Question 2

What is transpiration?

Answer 2

The loss of water vapour by evaporation

Question 3

What are the external features of a leaf?

Answer 3

Tip, lamina, midrib, margin, vein, base and petiole

Question 4

What are the 3 different leaf arrangements?

Answer 4

Alternate, opposite and whorled

Question 5

What does petiolate mean?

Answer 5

The leaf has a petiole ( leaf stalk)

Question 6

What does sessile mean?

Answer 6

The petiole is absent and the leaf blade attaches directly to the stem

Question 7

What are the internal structures of a leaf?

Answer 7

Cuticle, upper epidermis, palisade mesophyll cell, bundle sheath cell, xylem, phloem, lower epidermis, spongy mesophyll cells, guard cell, stoma and cuticle

Question 8

What’s the waxy cuticles function?

Answer 8

Protection and waterproofing

Question 9

What is the function of the epidermis?

Answer 9

Protection

Question 10

What is the function of the palisade mesophyll?

Answer 10

For photosynthesis

Question 11

What is the function of spongy mesophyll?

Answer 11

For photosynthesis and gaseous exchange

Question 12

What is the function of the guard cells?

Answer 12

To open and close stomata

Question 13

What is the function of the stomata?

Answer 13

Breathing pores

Question 14

What are xerophytic adaptations?

Answer 14

Adaptations that allow plants to survive in very dry conditions

Question 15

Examples of xerophytic adaptations

Answer 15

Small leaves, thick cuticle, leaves held parallel to sun rays and sunken stomata

Question 16

How do small leaves help plants survive in dry conditions?

Answer 16

Reduced surface area

Question 17

How does a thick cuticle help plants survive in dry conditions?

Answer 17

Waterproof layer on surface

Question 18

How do leaves being held parallel to sun rays help plants survive in dry conditions?

Answer 18

Absorb less radiation/ stay cooler

Question 19

How do sunken stomata help plants survive in dry conditions?

Answer 19

Trap water vapour

Question 20

Examples of simple leaves

Answer 20

Fagus salvatica, betula pendula and quercus robur

Question 21

What are monocots leaves like?

Answer 21

Monocots have long narrow leaves with parallel veins or venation

Question 22

What are dicot leaves like?

Answer 22

Dicots have reticulate veins or venation (branching)

Question 23

Examples of evergreen leaves

Answer 23

Ilex aquifolium, picea abies and taxus baccata

Question 24

What happens to deciduous leaves?

Answer 24

First they break down and reabsorb chlorophyll, sometimes leaving autumn colours due to other pigments such as carotenoids and xanthophylls, then they create an abscission layer

Question 25

What are deciduous?

Answer 25

Deciduous means the leaves are dropped in the autumn as they only stay on the tree for 1 growing season

Question 26

What happens in evergreen trees?

Answer 26

They can drop leaves in any season but once they are dropped they are replaced

Question 27

Why are evergreen leaves the way they are?

Answer 27

They live for one to 4 years and have to be able to survive drought and cold so they either have reduced leaves or thick leaves with a thick waxy cuticle

Question 28

Where is the leaves photosynthetic tissues?

Answer 28

It's found in the spongy and palisade mesophyll