Internal Structure of Leaves

Question 1

Outer layer of cells
Protects the leaf from mechanical injury, water loss, & pathogens.
Contains the stomata and has a cuticle.

Answer 1

Epidermis (upper & lower)

Question 2

Waxy layer covering the epidermis.
Reduces water loss through evaporation and provides a barrier against pathogens.

Answer 2

Cuticle

Question 3

Tissue located between the upper and lower epidermis
Primary site for photosynthesis

Answer 3

Mesophyll

Question 4

2 types of mesophyll

Answer 4

Palisade & Spongy

Question 5

Columnar cells located just beneath the upper epidermis.
Contains chloroplast for light absorption.

Answer 5

Palisade Mesophyll Cell

Question 6

Irregularly shaped cells located beneath the palisade mesophyll.
Provides space for gas exchange.

Answer 6

Spongy Mesophyll Cells

Question 7

Contains the vascular bundle, xylem, and phloem.

Answer 7

Vascular Tissue

Question 8

Vascular Tissue contains:

Answer 8

A. Vascular Bundle
B. Xylem
C. Phloem

Question 9

Contains the xylem & phloem
Present in all vascular plants

Answer 9

Vascular Bundle

Question 10

Transports water and nutrients from the roots to the leaves (upward)

Answer 10

Xylem

Question 11

Transports sugars and other organic compounds produced during photosynthesis to other parts of the plant (upward & downward).

Answer 11

Phloem

Question 12

-Surround vascular bundles (groups of xylem & phloem) as it provides structural support and protection.
-Found mainly in C4 and CAM
(Crassulacean Acid Metabolism) plants.

Answer 12

Bundle Sheath Cell

Question 13

-Tiny pores found on the lower epidermis.
-Facilitates gas exchange by allowing
CO2 to enter and 02 to exit.
-Also plays a role in transpiration.

Answer 13

Stomata

Question 14

-Kidney-shaped with thick inner walls and thin outer walls.
-Specialized cells that flank each stoma.
-Regulate the opening and closing of stomata to control gas exchange and water loss.

Answer 14

Guard Cells