B9 Cells

Question 1

What are the differences in the structure of plant and animal cells?

Answer 1

Plant:
•cell wall
•chloroplasts
•vacuole

Question 2

What is a prokaryotic cell?

Answer 2

Bacteria cells

Question 3

What is a eukaryotic cell?

Answer 3

An animal or plant cell

Question 4

What do prokaryotic cells have?

Answer 4

Plasmids
Slime capsule
Flagella
Pili
Ribosomes

Question 5

How big are eukaryotic cells compared to prokaryotic cells?

Answer 5

Typically, eukaryotic cells are one order of magnitude bigger than prokaryotic cells

Question 6

What is diffusion?

Answer 6

The movement of particles from an area of high concentration to an area of low concentration (until equilibrium is reached)

Question 7

In which states of matter can diffusion occur?

Answer 7

Liquids or gases

Question 8

What is osmosis?

Answer 8

A special type of diffusion- the movement of water from a dilute to a more concentrated solution through a selectively permeable membrane that allows water to pass through.

Question 9

What can cause osmosis?

Answer 9

Differences in the concentrations of solutions inside and outside of a cell can cause water to move in or out of the cell by osmosis

Question 10

What damage can osmosis cause?

Answer 10

It can cause animal cells to be damaged if the concentration outside the cell changes dramatically

Question 11

What is a key fact about the concentration of water?

Answer 11

If the glucose concentration is high, the water concentration is low

Question 12

What is a second definition of osmosis?

Answer 12

Movement from a low concentration of solute to a high concentration of solute

Question 13

What is active transport?

Answer 13

It allows cells to move from an area of low concentration to an area of high concentration (against the concentration gradient)

Question 14

Why is active transport useful in cells?

Answer 14

Cells can absorb ions from very dilute substances and they can also move substances such as sugars and ions through the cell membrane

Question 15

What else is needed for active transport?

Answer 15

Energy is needed. The rate of respiration and the rate of active transport are closely linked.

Question 16

Why is active transport useful in digestion?

Answer 16

Active transport enables sugar used for cell respiration to be absorbed from the gut into the blood

Question 17

What are the four adaptations for exchanging materials?

Answer 17

1) large surface area
2) thin membrane
3) efficient blood supply
4) being ventilated (in animals)

Question 18

What is mitosis?

Answer 18

A process involved in cell division that produces two identical cells

Question 19

What are the five steps in mitosis?

Answer 19

1) the two pairs of chromosomes are copied
2) the chromosomes are forced to the centre by the spindle finders
3) the chromosomes attach to the spindle finders
4) two nuclei are formed
5) the cell splits, creating two identical cells

Question 20

Why does mitosis need to occur?

Answer 20

To produce extra cells needed for growth and development to replace worn out or damaged cells

Question 21

How do embryos grow?

Answer 21

Cells split in two every day to form a bundle of cells called an embryo

Question 22

What is special about embryonic stem cells?

Answer 22

They can become any specialised human cell

Question 23

What happens after about a week of pregnancy?

Answer 23

The cells stop being the same and begin to differentiate (into different types of cell)

Question 24

What happens next to the specialised cells?

Answer 24

The cells continue to differentiate until they become specialised cells

Question 25

What is the difference between adult and embryo stem cells

Answer 25

Adult stem cells are already specialised. They can only become more specialised