Cell structure (white)

Question 1

What is the size range of an average animal or plant cell?

Answer 1

0.01 – 0.10 mm

Question 2

How many micrometres (μm) are in a millimetre (mm)?

Answer 2

1000

Question 3

How many nanometres (nm) are in a micrometre (μm)?

Answer 3

1000

Question 4

What is 1 micrometre (1 μm) in metres, as standard form?

Answer 4

1 × 10^-6 m

Question 5

What is 1 nanometre (1 nm) in metres, as standard form?

Answer 5

1 × 10^-9 m

Question 6

A red blood cell has a diameter of 7 μm.

What is its diameter in metres as stand form?

Answer 6

7 × 10^-6 m

Question 7

Describe how to set up a light microscope to view an image of a cell.

Answer 7

1. Rotate the nose piece to start on the lowest power objective lens (e.g. x10).
2. Turn the coarse focus so that the stage is as close to the objective lens as possible.
3. Place the microscope slide on the stage.
4. Focus the slide by turning the coarse focus.
5. Turn to a higher power objective lens.
6. Adjust the focus using the fine focus knob.

Question 8

What is the function of the cytoplasm?

Answer 8

A jelly-like material that contains dissolved nutrients and salts and structures called organelles. It is where many of the chemical reactions happen.

Question 9

What is the function of the nucleus?

Answer 9

Contains genetic material, including DNA, which controls the cell’s activities.

Question 10

What is the function of the cell membrane?

Answer 10

controls the movement of substances in and out of the cell.

Question 11

What is the function of the mitochondria?

Answer 11

Organelles that contain the enzymes for respiration, and where most energy is released in respiration.

Question 12

What is the function of the ribosomes?

Answer 12

Tiny structures where protein synthesis occurs.

Question 13

Which three organelles are found in a plant cell, but not an animal cell?

Answer 13

• Cell wall
• Chloroplasts
• Vacuole

Question 14

What is the function of the chloroplasts?

Answer 14

Organelles that contains the green pigment, chlorophyll, which absorbs light energy for photosynthesis. Contains the enzymes needed for photosynthesis.

Question 15

What is the cell wall made from?

Answer 15

Cellulose fibres

Question 16

What is the function of the cell wall?

Answer 16

Strengthens the cell and supports the plant.

Question 17

What is the function of the vacuole?

Answer 17

Filled with cell sap to keep the plant cell turgid.

Question 18

How much bigger is the length of the leaf cell compared to the diameter of the red blood cell?

Answer 18

10 times

Question 19

How many times greater is the length of the bacterium compared to the length of the HIV virus?

Answer 19

10 times

Question 20

What is the width of a cheek cell compared with a Salmonella bacterium?

Answer 20

70 / 0.5

= 140 times

Question 21

The width of a human hair is 100 μm, while the width of the HIV is 100 nm.

What is the difference in order of magnitude for a human hair and HIV?

Answer 21

The difference in order of magnitude is 3.

Calculation:

The width of the human hair is 100 μm = 10^-4 m

The width of the HIV is 100 nm = 10^-7 m

Question 22

What are three examples of eukaryotic cells?

Answer 22

Animals, plants, fungi

Question 23

Bacteria are examples of [prokaryotic / eukaryotic] cells.

Answer 23

prokaryotic

Question 24

How do prokaryotic cells divide?

Answer 24

By binary fission

Question 25

Describe the structures in a prokaryotic cell.

Answer 25

• Have a cell wall
• No mitochondria, no chloroplasts
• No nucleus - DNA free in cytoplasm, or in rings called plasmids

Question 26

What are the two types of prokarotic cell?

Answer 26

Bacteria and Archaea

Question 27

What are some adaptations of a sperm cell that help it with its function?

Answer 27

• The acrosome in the head contains enzymes so that the sperm can penetrate an egg.
• The middle piece is packed with mitochondria to release energy needed to swim and fertilise the egg.
• The tail enables the sperm to swim.

Question 28

What are some adaptations of a nerve cell that help it with its function?

Answer 28

• The nerve cell is extended, so that nerves can run to and from different parts of the body to the central nervous system.
• The cell has extensions and branches, so that it can communicate with other nerve cells, muscles and glands.
• The nerve cell is covered with a fatty sheath, which insulates the nerve cell and speeds up the nerve impulse.

Question 29

What are some adaptations of a muscle cell that help it with its function?

Answer 29

• Muscle cells contain filaments of protein that slide over each other to cause muscle contraction.
• They contain many well-developed mitochondria to provide the energy for muscle contraction.
• In skeletal muscle, the cells merge so that the muscle fibres contract in unison.

Question 30

How is a root hair cell adapted for its function?

Answer 30

• The root hair cell has a large surface area to provide contact with soil water.
• It has thin walls so as not to restrict the movement of water.

Question 31

Which specialised plant cell is this?

Answer 31

Root hair cell

Question 32

How are xylem cells adapted for their function?

Answer 32

• There are no top and bottom walls between xylem vessels, so there is a continuous column of water running through them.
• Their walls become thickened and woody. They therefore support the plant.

Question 33

How are phloem cells adapted for their function?

Answer 33

Dissolved sugars and amino acids can be transported both up and down the stem.

Companion cells, adjacent to the sieve tubes provide energy required to transport substances in the phloem.