Cells

Question 1

What research resulted in cell theory?

Answer 1

In 1665 Robert Hooke looked at slices of cork under a microscope and discovered compartments he named cells

Question 2

Identify the elements of cell theory

Answer 2

All cells are made from pre-existing cells
All known living things are made up of one or more cells
The activity of an organism depends on the total activity of independent cells
Energy flow occurs within cells
Cells contain DNA & RNA
All cells are basically the same in chemical composition in organisms of similar species

Question 3

List the basic components of a eurkaryotic cell

Answer 3

Complex structure
DNA contained in the nucleus
Single or multi-celled organisms
Includes animals, plants, fungi etc.

Question 4

Describe the basic structure of a eurkaryotic cell

Answer 4

Cell membrane encases cell contents including

cytoplasm, organelles cytosol and the nucleus which contains DNA

Question 5

Define organelles

Answer 5

‘Little organs’ are structures within a cell that perform cellular tasks. They are either nonmembranous or membranous

Question 6

List nonmembranous organelles

Answer 6

Cytoskeleton 
Microvilli
Centrioles
Cilia
Ribosomes

Question 7

List membranous organelles

Answer 7

Mitochondria
Endoplasmic Reticulum 
Golgi Complex
Lysosomes
Peroxisomes

Question 8

What are the differences between membranous and nonmembranous organelles?

Answer 8

Nonmembranous: Are not covered by a membrane and are in direct contact with cytosol
Membranous: Are separated from cytosol by membrane

Question 9

What three components make up the cytoskeleton?

Answer 9

Mircofilaments
Intermediate filaments
Microtubules

Question 10

List two components of microfilaments

Answer 10

• Contain actin and myosin

- Possess contractile ability

Question 11

What do intermediate filaments do?

Answer 11

Stabilise cell and cell components

Question 12

List two components of microtubules

Answer 12

• Determining cell shape

- They are involved in movement

Question 13

Describe microvilli

Answer 13

Small finger-like projections that increase the surface area of cell and line the areas of the digestive tract

Question 14

Describe cilia

Answer 14

Long finger-like extensions of cells that line the respiratory tract, can beat in rhythm and move mucus to the throat for swallowing

Question 15

Describe centrioles

Answer 15

Short sections of microtubules surrounded by centrosome and form spindle structures during cell division

Question 16

Where are ribosomes found?

Answer 16

Ribosomes are either dispersed freely in cytoplasm or fixed on rough endoplasmic reticulum, they are also found in the mitochondria

Question 17

What do ribosomes do?

Answer 17

Synthesise proteins

Question 18

Describe mitochondria

Answer 18

They are the sites of energy production, thought to originate from bacteria, contain their own DNA and produce the majority of ATP

Question 19

Describe endoplasmic reticulum

Answer 19

Membrane network of flattened sacs and tubules attached to the nuclear envelope

Question 20

Describe rough endoplasmic reticulum

Answer 20

It is continuous with the nuclear membrane with ribosomes on the surface and are involved in the manufacture of proteins

Question 21

Describe smooth endoplasmic reticulum

Answer 21

It extends from rough endoplasmic reticulum and synthesise fatty acids and steroids

Question 22

What processes are the enzymes of smooth endoplasmic reticulum involved in?

Answer 22

• Inactivation and detoxification of drugs, alcohol, pesticides and carcinogens
• Breakdown of glycogen to glucose in the liver

Question 23

What is the function of the golgi complex?

Answer 23

It modifies, sorts and packages proteins and lipids

Question 24

What is the golgi complex?

Answer 24

A flattened collection of sacs called cisternae

Question 25

What is the function of lysosomes?

Answer 25

They are involved in garbage disposal and recycling, fusing with vesicles containing damaged organelles and bacteria. They break down the contents and eject unwanted components from the cell

Question 26

What are peroxisomes?

Answer 26

Small vesicles containing powerful oxidising enzymes that detoxify harmful substances such as alcohol. pH of which is 5-100x more acidic than cytosol

Question 27

Where are peroxisomes most prevalent?

Answer 27

Liver cells