4. Plant Tissues and Organs

Question 1

Provide the definition of Tissue.

Answer 1

Group of similar cells adapted for a particular function.

Question 2

Provide the definition of Organs.

Answer 2

Group of different tissues performing specific functions.

Question 3

Provide the definition of Cell differentiation.

Answer 3

Cells develop specific structures for specific functions.

Question 4

Name the 2 types of Meristematic tissue.

Answer 4

• Apical meristem
• Lateral meristem

Question 5

Where is the Apical meristem found?

Answer 5

Growing tip of stem and root.

Question 7

In what way does the Apical meristem increase?

Answer 7

Length of root and stem

Question 8

What is the Lateral meristem known as?

Answer 8

Cambium

Question 9

Where is the Lateral meristem found?

Answer 9

Lateral sides of stem and root.

Question 10

In what way does the Lateral meristem increase?

Answer 10

Width of stem and root.

Question 11

Give 4 functions of the Epidermis suited to it’s function.

Answer 11

1. Outer layer around roots, stems and leaves which protect underlying tissue from injury.
2. Single layer of brick-shaped cells to regulate gaseous and water loss.
3. Cells are transparent with no intercellular air spaces which allows sunlight through for photosynthesis.
4. Covered with a waxy cuticle to reduce water loss.

Question 13

Name the 4 types of Ground tissue.

Answer 13

1. Parenchyma
2. Chlorechyma
3. Collenchyma
4. Sclerenchyma

Question 14

Provide 3 structures of Parenchyma.

Answer 14

• Thin cell walls
• Large intercellular air spaces
• Large vacuoles

Question 15

Give 2 functions of Parenchyma.

Answer 15

• Stores food and water
• Allows for gaseous exchange and water movement.

Question 16

Provide 1 structure of Chlorenchyma.

Answer 16

Specialised parenchyma with chloroplasts

Question 17

Give 1 function of Chlorenchyma.

Answer 17

Photosynthesis

Question 18

Provide 1 structure of Collenchyma.

Answer 18

Cell walls thickened in corners.

Question 19

Give 1 function of Collenchyma.

Answer 19

Structure and support (bending)

Question 20

Provide 3 structures of Sclerenchyma.

Answer 20

• Thick cell walls made of lignin
• Cells are dead and hollow
• Fibres and sclereids

Question 21

Give 1 function of Sclerenchyma.

Answer 21

Structure and support (no bending)

Question 22

Name the 2 Vascular tissues.

Answer 22

Xylem and Phloem

Question 23

Give 3 structures of the Xylem suited to it’s function.

Answer 23

1. Cell walls thickened by lignin for strengthening and support.
2. Perforation plates for easy transport of water.
3. Walls of vessels and tracheids with pits for lateral transport.

Question 24

Give 3 structures of the Phloem suited to it’s function

Answer 24

1. Living, elongated cells without thickened walls to transport organic substances from leaves to rest of plant.
2. Sieve tubes and Companion cells to support sieve tubes.
3. End walls of sieve tubes with sieve plates to form continuous plates for easy transport.

Question 25

Provide 5 functions of the Root.

Answer 25

- Anchorage - Support - Storage - Transport - Reproduction

Question 26

What 4 things does the External structure of the root consist of?

Answer 26

- Root cap - Meristematic region - Region of elongation - Mature region

Question 27

Give 2 functions of the Root cap.

Answer 27

- Protects meristem - Helps root tip slide through soil easily

Question 28

Give the function of the Meristematic region.

Answer 28

Active cell division

Question 29

Give the function of the Region of elongation.

Answer 29

Where root grows longer.

Question 30

Give 2 functions of the Mature region.

Answer 30

- Many root hairs to increase surface area for water dispersion. - Lateral roots and fully differentiated tissues.

Question 31

What 3 things does the Internal structure of the root consist of?

Answer 31

- Epidermis - Cortex - Central cylinder

Question 32

What is the Epidermis in terms of the Root?

Answer 32

- Outer layer of root - Contains root hairs

Question 33

What is the Cortex in terms of the Root?

Answer 33

- Parenchyma cells with large intercellular air spaces. - Innermost layer consists of a single layer of endodermis cells. - Endodermis wall contains Casparian strips

Question 34

What is the Central Cylinder of the Root?

Answer 34

- Upper endodermis there is thin-walled cells called pericycle. - Inside of pericycle is xylem and phloem.

Question 35

Provide 5 functions of the Stem.

Answer 35

- Transport - Storage - Anchorage - Protection - Photosynthesis

Question 36

What does the Internal structure of a stem consist of?

Answer 36

- Epidermis - Cortex - Central cylinder

Question 37

What is the Epidermis in terms of the Stem?

Answer 37

- Outer layer of stem

Question 38

What is the Cortex in terms of the Stem?

Answer 38

Collenchyma, Parenchyma and Endodermis.

Question 39

What is the Central Cylinder in terms of the Stem?

Answer 39

- Xylem and Phloem in vascular bundles. - Cambium makes secondary thickening possible. - Central region is pith of parenchyma cells. - Xylem on inside, Phloem on outside.

Question 40

Provide 3 functions of the Leaf.

Answer 40

- Photosynthesis - Transpiration - Gaseous exchange

Question 41

What does the Leaf consist of?

Answer 41

- Epidermis - Mesophyll - Vascular bundles

Question 42

Give 4 structures of the Epidermis suited to it's function in a Leaf.

Answer 42

1. Covers upper and lower surfaces to protect underlying tissue. 2. Transparent to allow light through for photosynthesis. 3. Waxy cuticle to reduce excessive moisture loss. 4. Stomata for gaseous exchange and transpiration.

Question 43

Give 3 structures and functions of Palisade cells in Mesophyll in a Leaf.

Answer 43

- Cell walls are thin for easy diffusion. - Alot of chloroplasts for maximum photosynthesis. - Elongated cells under upper epidermis for deep penetration of light.

Question 44

Give 2 structures and functions of Spongy cells in Mesophyll in a Leaf.

Answer 44

- Many chloroplasts - Parenchyma with large intercellular air spaces responsible for photosynthesis an gaseous exchange.

Question 45

Give the structure of a Vascular bundle in a Leaf.

Answer 45

Xylem and Phloem

Question 46

Give 2 functions of the Vascular bundle in a Leaf.

Answer 46

- Xylem transports water and dissolved mineral salts to mesophyll cells. - Phloem transports organic nutrients to other parts of plant.