6.4 - The Organisation and Specialisation of Cells

Question 1

What is the basic unit of life in multicellular organisms?

Answer 1

The basic unit of life is the cell, and multicellular organisms are made up of many cells that specialize in different functions.

Question 2

What are the levels of organization in a multicellular organism?

Answer 2

1. Specialized cells
2. Tissues
3. Organs
4. Organ systems
5. Whole organism

Question 3

What does it mean when a cell is specialized?

Answer 3

A specialized cell is differentiated, meaning it has developed specific features to carry out a particular function in the body.

Question 4

What are erythrocytes and how are they specialized?

Answer 4

Erythrocytes (red blood cells) have a biconcave shape, which increases their surface area for oxygen transport. They lack a nucleus to make more room for hemoglobin, and they are flexible to squeeze through narrow capillaries.

Question 5

What is the function of neutrophils?

Answer 5

Neutrophils are white blood cells that play a key role in the immune system. They have a multi-lobed nucleus to help them squeeze through small gaps to reach infection sites and contain lysosomes that help break down pathogens.

Question 6

How are palisade cells specialized for photosynthesis?

Answer 6

Palisade cells contain chloroplasts for absorbing light. They are rectangular, tightly packed to form layers, and have thin cell walls to allow efficient diffusion of carbon dioxide. They also have a large vacuole to maintain turgor pressure.

Question 7

What is the function of root hair cells?

Answer 7

Root hair cells have long extensions called root hairs, which increase the surface area for the absorption of water and minerals from the soil.

Question 8

What is the role of guard cells?

Answer 8

Guard cells surround stomata (small openings) on plant leaves. When guard cells lose water, they become less swollen and change shape, causing the stomata to close and prevent water loss. This regulates gas exchange for photosynthesis.

Question 9

What are the four main types of tissues in animals?

Answer 9

Nervous tissue.
Epithelial tissue.
Muscle tissue.
Connective tissue.

Question 10

What is the role of the: nervous tissue?

Answer 10

Supports electrical impulse transmission.

Question 11

What is the role of the: epithelial tissue?

Answer 11

Covers body surfaces, both internal and external.

Question 12

What is the role of the: muscle tissue?

Answer 12

Allows for contraction and movement.

Question 13

What is the role of the: connective tissue?

Answer 13

Holds tissues together or serves as a transport medium.

Question 14

What is squamous epithelial tissue?

Answer 14

Squamous epithelial tissue is made up of flat, thin cells. It forms a single layer of cells, making it ideal for processes like diffusion, such as in the lining of the lungs where oxygen diffuses into the blood.

Question 15

What is the role of ciliated epithelial tissue?

Answer 15

Ciliated epithelial tissue has cells with cilia that move rhythmically to sweep mucus and trapped particles (such as bacteria) away from the lungs, preventing them from reaching the alveoli.

Question 16

What is cartilage?

Answer 16

Cartilage is a flexible connective tissue found in areas like the outer ear and between bones. It contains elastic and collagen fibers, providing support and preventing bones from rubbing together.

Question 17

What is the function of muscle tissue?

Answer 17

Muscle tissue contracts to move bones and parts of the body. Skeletal muscle fibers contain myofibrils that contract using proteins, enabling movement.

Question 18

What is the function of the epidermis tissue in plants?

Answer 18

Epidermis tissue covers the surface of plants. It often has a waxy cuticle to reduce water loss and may contain stomata for gas exchange.

Question 19

What is the role of xylem tissue in plants?

Answer 19

Xylem tissue is responsible for transporting water and minerals from the roots to the rest of the plant. It consists of dead vessel elements whose walls are strengthened with lignin for structural support.

Question 20

What is the function of phloem tissue?

Answer 20

Phloem tissue transports organic nutrients, particularly sucrose, from the leaves to other parts of the plant. It consists of sieve tube cells separated by sieve plates.

Question 21

What is an organ? Give an example.

Answer 21

An organ is a structure made up of different tissues working together to perform a specific function. For example, the heart is an organ composed of muscle tissue and connective tissue that pumps blood around the body.

Question 22

What is the function of the heart?

Answer 22

The heart pumps blood through the body, providing a transport system for oxygen, nutrients, and waste products. It is made up of muscle tissue and connective tissue.

Question 23

What is the role of the leaf in plants?

Answer 23

The leaf is an organ responsible for photosynthesis. It contains epidermal tissue for protection and vascular tissue (xylem and phloem) for transport of water, minerals, and nutrients.

Question 24

What is the role of the digestive system?

Answer 24

The digestive system processes food by breaking it down into smaller, soluble molecules that can be absorbed into the blood. It also reabsorbs water and eliminates undigested material.

Question 25

What is the function of the cardiovascular system?

Answer 25

The cardiovascular system circulates blood throughout the body, transporting substances like oxygen, nutrients, and waste products.

Question 26

What is the role of the gaseous exchange system?

Answer 26

The gaseous exchange system brings oxygen into the body for respiration and removes carbon dioxide produced by cellular respiration.