B9 Cells Flashcards Preview

Science > B9 Cells > Flashcards

Flashcards in B9 Cells Deck (25)
Loading flashcards...
1

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

Plant:
•cell wall
•chloroplasts
•vacuole

2

What is a prokaryotic cell?

Bacteria cells

3

What is a eukaryotic cell?

An animal or plant cell

4

What do prokaryotic cells have?

Plasmids
Slime capsule
Flagella
Pili
Ribosomes

5

How big are eukaryotic cells compared to prokaryotic cells?

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

6

What is diffusion?

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

7

In which states of matter can diffusion occur?

Liquids or gases

8

What is osmosis?

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.

9

What can cause osmosis?

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

10

What damage can osmosis cause?

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

11

What is a key fact about the concentration of water?

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

12

What is a second definition of osmosis?

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

13

What is active transport?

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

14

Why is active transport useful in cells?

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

15

What else is needed for active transport?

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

16

Why is active transport useful in digestion?

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

17

What are the four adaptations for exchanging materials?

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

18

What is mitosis?

A process involved in cell division that produces two identical cells

19

What are the five steps in mitosis?

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

20

Why does mitosis need to occur?

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

21

How do embryos grow?

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

22

What is special about embryonic stem cells?

They can become any specialised human cell

23

What happens after about a week of pregnancy?

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

24

What happens next to the specialised cells?

The cells continue to differentiate until they become specialised cells

25

What is the difference between adult and embryo stem cells

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