2.3 Living Processes of Multicellular Organisms

Question 1

Epithelium cell

Answer 1

Structural adaptation:

Thin cells; arranged closely

Function:

Provide protection
Aids in gaseous exchange
Helps in nutrients absorption, secretes mucus

Question 2

Muscles cell

Answer 2

Structural adaptation:

Contains many fibres; aid in movement
Have many mitochondria; provide energy for muscle contraction

Function: Contracts to produce movement

Question 3

Nerves cell

Answer 3

Structural adaptation:

Have long dendrites and axon
Axons covered with myelin sheath; faster transmission

Function: Transmits nerve impulse from one part to another part of the body

Question 4

Red blood cell

Answer 4

Structural adaption:

Contains haemoglobin; transport oxygen
Has a biconcave disc shape; increases the ratio of surface area per volume

Function: Transports respiratory gases

Question 5

White blood cell

Answer 5

Structural adaption:

Can change shape; easily squeeze through the tiny blood vessels

Function: Protects the body from pathogens

Question 6

Sperm cell

Answer 6

Structural adaption:

Has a long tail; helps the sperm to move
Contains mitochondrion; provide energy for the sperm to swim
Contains enzymes; helps the sperm to penetrate the ovum

Function: Fertilises the ovum

Question 7

Spongy palisade mesophyll cell

Answer 7

Structural adaptation:

Packed loosely; efficient gaseous exchange

Function: Facilitate gas permeation

Question 8

Xylem

Answer 8

Structural adaptation:

Consists of porous long tubes; to transport substances efficiently
Strengthen by lignin; to prevent the xylem from collapse

Function: Transport water and mineral salts from the roots to a whole plant

Question 9

Sieve tubes

Answer 9

Structural adaptation:

Matured sieve tubes have no nucleus; provide more space for transportation
Have sieve plates
No lignin

Function: Transport organic substances; sucrose, amino acids and hormones from the shoots to other parts of the plant

Question 10

Root hair cell

Answer 10

Structural adaptation:

Have many mitochondria; provide energy to absorb more mineral salts through active transport
The root hairs increase the surface area; maximising the absorption

Function: Absorb water and dissolved mineral salts

Question 11

Guard cell

Answer 11

Structural adaptation:

Have chloroplasts; produce glucose
Have a large vacuole; control the osmotic pressure of the cell; aid in controlling the opening and closing of the stoma

Function: Control the opening and closing of the stoma

Question 12

Cell Organisation:

Epithelium

Answer 12

• Consists of one or more layers of cells
• Some epithelium tissues form glands (exocrine and endocrine glands)
• Epithelial tissues carry out functions associated with protection, secretion and absorption

Question 13

Muscles

Answer 13

Musculoskeletal: involves involuntary movements; contracts and relaxes to move the bones

Smooth: contracts and relaxes that allows involuntary movements; peristalsis in intestines

Cardiac: found in the heart walls; contracts and relaxes that allows pumping the blood

Question 14

Nerve

Answer 14

• Consists of neurons or nerve cells

- Transmit nerve impulses, control and coordinates the activities in the body

Question 15

Connective

Answer 15

• Consists of several types of cells and fibres that are distributed across the body that has many functions

Question 16

1. Loose connective tissues
2. Fibrous connective tissues
3. Cartilage
4. Bone
5. Blood tissues
6. Adipose tissues

Answer 16

1. Places between the organs
   Functions to anchor the epithelium tissues to other tissues and places the organs in one place
2. Consists of fibrous collagens that are arranged close to one another
   Found in tendon and ligament
3. Strong and flexible
   Supports the nose, ears and covers the end of the bones, which functions to absorb pressure and shock
4. Consists of cells in one matrix of mineral salts and fibrous collagen
   Collagen matrix is hardened by the deposition of minerals such as calcium phosphate
   Functions to protect the organs and provides support to the body
5. Consists of blood cells; red blood cells, white blood cells and platelets
   Blood functions to protect, transport and regulate
6. Functions to store fats, protects the organs and insulates heat
   Found in the skin dermis and at the surroundings of the organs

Question 17

Meristematic tissue

Answer 17

A group of undifferentiated cells; active in cell division

Two types; apical and lateral meristems

Function:

Apical meristem: primary growth; vertical growth
Lateral meristem: secondary growth; horizontal growth

Question 18

Parenchyma tissue

Answer 18

Thin-walled cells; loosely arranged with spaces between them

Function:

• Provides support and shapes
• Stores food
• Conducts photosynthesis

Question 19

Collenchyma tissue

Answer 19

Elongated, polygonal cells with unevenly thickened cell walls

Function:

Provides support to:

• Herbaceous plants
• Young stems
• Leaf stalks
  Petioles

Question 20

Sclerenchyma tissue

Answer 20

The cells are rigid
Have cell walls; thickened by lignin

Function:

• Provide support and protection to the plant

Question 21

Epidermis

Answer 21

The wall of epidermal cells is normally covered by cuticle

Function:

The cuticle on the epidermal tissue helps to:

• Prevent water loss
• Protects the plants from mechanical injury
• Prevent the invasion by disease-causing microorganisms

In roots:
- the epidermal cells have long projections called root hairs; increase the surface area for absorption of water and minerals

In leaves:
- the lower epidermis contains guard cells; controls the opening and closing of stomata

Question 22

Xylem

Answer 22

Consists of xylem vessels; long tubes joined together end to end
Provide support to plants

Function:

Xylem carries water and minerals from the roots to the leaves
Xylem provides support and mechanical strength to the plant

Question 23

Phloem

Answer 23

Phloem tissue consists of parenchyma cells, sieve tubes and companion cells
Sieve tubes obtain nutrients and energy from the companion cells

Function:

Transports carbohydrates, amino acids, hormones from the leaves to storage organs and to the growing parts of plants