SB6 Plant structures and their functions

Question 1

What are the different tissues in a leaf. List in order from top to bottom

Answer 1

Waxy cuticle
Upper epidermis
Palisade layer
Spongy mesophyll and vascular bundle
Lower epidermis, guard cells and stomata
Waxy cuticle

Question 2

What are the functions of each of the tissues in the leaf

Answer 2

Waxy cuticle - prevent water loss (by evaporation)
Upper epidermis - transparent to allow light to pass through to the palisde layer
Palisade layer - where photosynthesis occurs
Spongy mesophyll - contains air spaces for more efficient gas exchange
Vascular bundle - provide water and take the glucose from photosynthesis
Lower epidermis - contains guard cells which open and close the stomata for efficient gas exchange

Question 3

What are some adaptations that plants have to live in extreme conditions

Answer 3

Cacti

• stems to store water
• deep roots to collect water from deep underground
• spines (modified leaves) to minimize surface area so water loss is reduced and for protection from harmful animals
• very thick waxy cuticle to reduce water loss by evaporation
• less stomata to prevent water loss by transpiration