Cells

Question 1

What does the Cell Theory state?

Answer 1

1. All living things are made up of cells.
2. Cells are the smallest working units of all living things.
3. All cells come from preexisting cells through cell division.
4. All cells can carry out all characteristics of living things.

Question 2

What are Cells?

Answer 2

A cell is the smallest unit that is capable of performing life functions.

Question 3

What are the characteristics of prokaryotic cells?

Answer 3

1. Do not have structures surrounded by membranes.
2. Few internal structures.
3. One-celled organisms. Bacteria, Virus.

Question 4

What are the Characteristics of Eukaryotic cells?

Answer 4

1. Contain organelles surrounded by membranes.

2. Most living organisms are Eukaryotic.

Question 5

What does the cell membrane do?

Answer 5

It is the outer membrane of the cell that controls movement in and out of the cell (selectively permeable). It has a double layer.

Question 6

What does a cell wall do?

Answer 6

It is most commonly found in plant cells and bacteria. It is made of polysaccharides.
It supports and protects cells.
Plant cell is made of cellulose.

Question 7

What is the function of the nucleus?

Answer 7

It directs the cells’ activities.
It is separated from the cytoplasm by nuclear membrane.
It contains genetic material. It contains chromosomes made of DNA.
The chromosomes contain instructions for traits and characteristics.

Question 8

What is the Cytoplasm?

Answer 8

It is a gel-like mixture.
Surrounded by cell membrane.
Site of most metabolic reaction.

Question 9

What is the Endoplasmic Reticulum?

Answer 9

1. Moves materials around in cell.
2. Smooth type: lacks ribosomes.
3. Rough type (pictured): ribosomes embedded in surface.

Question 10

What are Ribosomes?

Answer 10

1. Each cell contains thousands.
2. Make proteins
3. Found on ribosomes and floating throughout the cell.

Question 11

What is a Mitochondrion?

Answer 11

1. It is a rod shaped organelle that produces energy through chemical reactions - breaking down fats and carbohydrates.
2. Controls level of water and other materials in cell.
3. Recycles and breaks down proteins, fats and carbohydrates.

Question 12

What are Golgi Bodies?

Answer 12

1. It packages protein.
2. It moves materials within the cells.
3. Moves materials out of the cell.

Question 13

What are Vacuoles?

Answer 13

1. Membrane - bound sacs for storage, digestion and waste removal.
2. Contains water solution
3. Help plants maintain shape.

Question 14

What are Chloroplasts?

Answer 14

They are usually found in plant cells but can be found in bacteria.
Contains green chlorophyll.
Where photosynthesis takes place.

Question 15

How do cells specialise?

Answer 15

Newly-formed cells in a multi-cellular organism become specialised by turning different genes on and off.
This is known as Differentiation.

Question 16

What are Erythrocytes?

Answer 16

They carry oxygen from the lungs to respiring tissues. 
1. Contain large amounts of Hb
2. Have no nucleus.
3. Are bioconcave
4. Have large surface area
5.

Question 17

What are Ciliated Cells?

Answer 17

They are epithelial cells which are column shaped and cover many surfaces.
They have tiny projections on their exposed surface called cilia. They move in a synchronised pattern to move mucus, produced by goblet cells along the surface.
eg. Trachea, uterus and bronchi.

Question 18

What is a spermatozoa?

Answer 18

Spermatozoa are motile reproductive cells, which carries a male’s genetic information.
Their motility comes from their undulipodium whose energy comes the mid-piece Mitochondria.
They have a haploid nucleus with an acrosome with hydrolytic and glycolytic enzymes for dissolving the ovum coat of the egg.

Question 19

What are Root hair cells?

Answer 19

They are epithelial cells found in the roots of plants.
They have a large surface area due to their hair-like projections which make water and mineral absorption easier.
Their large amount of mitochondria provide large amounts of mitochondria which assist with active transport.

Question 20

What are Xylem Vessels?

Answer 20

Xylem tissue consist of xylem vessels and parenchyma cells.
They are made of dead, elongated cells and waterproofed with lignin deposits.
They have no end walls so their cells form tubes with wide lumens.
They also support the plant.

Question 21

What are Phloem Tissue?

Answer 21

Phloem tissue is made up of sieve tubes and companion cells.
Sieve tubes line up and their ends form sieve plates through which substances move.
They companion cells beside the sieve tubes perform the cell’s metabolic functions.

Question 22

What are Muscle Cells?

Answer 22

They are elongated and elastic cells.
They have many mitochondria.
The strands of protein slide over each other making the muscle cell (fibre) shorter and causing the muscle to contract.