B1 - Cells And Organisation

Question 1

Can a solid diffuse?

Answer 1

No

Question 2

Can a liquid diffuse?

Answer 2

Yes

Question 3

Can a gas diffuse?

Answer 3

Yes

Question 4

Whats the definition of diffusion?

Answer 4

The net movements of particles from an area of high concentration to an area of low concentration. Due to the random movement of particles. A passive process which means that no energy is needed.

Question 5

Whats a difference in concentration between two areas?

Answer 5

Concentration gradient

Question 6

List some factors that affect diffusion

Answer 6

Concentration gradient
Temperature
Large surface area

Question 7

There is faster diffusion when there is…

Answer 7

Large concentration gradient
Higher temperature
Larger surface area

Question 8

Surface Area to Volume Ratio means that…

Answer 8

The surface area to volume ratio falls as the object gets bigger.

Question 9

What does dilute mean?

Answer 9

Weak

Question 10

What does concentrated mean?

Answer 10

Strong

Question 11

Definition of osmosis:

Answer 11

Osmosis is the movement of water molecules from a region of higher water concentration to a region of lower water concentration across a partially permeable membrane

Question 12

Definition of isotonic:

Answer 12

If the concentration of the solutes in the solution outside the cell is the same as the internal concentration, the solution is isotonic to the cell.

Question 13

Definition of hypertonic

Answer 13

If the concentration of the solutes in the solution outside the cell is higher than the internal concentration, the solution is hyertonic to the cell.

Question 14

Definition of hypotonic

Answer 14

If the concentration of solutes in the solution oustside the cell is lower than the internal concentration, the solution is hypotonic to the cell.

Question 15

What is the function of the cell membrane?

Answer 15

Controls what enters and leaves the cell

Question 16

What are eukaryotes?

Answer 16

They are cells that are complex and include all animal and plant cells

Question 17

What are Prokaryotic cells?

Answer 17

Prokaryotic cells are single-celled organisms and are much smaller and simpler ( e.g. bacteria)

Question 18

What are plasmids?

Answer 18

Small rings of DNA

Question 19

What is the function of a ribosome?

Answer 19

It is where all the protiens are made in the cell and it is the place where protein synthesis happens

Question 20

What is the function of the mitochondria?

Answer 20

It is the site of aerobic respiration ( release of energy from food )

Question 21

What is the function of a cytoplasm?

Answer 21

It is the place where chemical reactions take place in the cell

Question 22

What is the function of the nucleus?

Answer 22

• controls the cell
• contains the genetic information called DNA

Question 23

What is the function of the cellulose and the cell wall?

Answer 23

The cell wall is made of cellulose and it supports the cell and strengthens it

Question 24

What is the formula for magnification?

Answer 24

Magnification x real size

Question 25

How do you prepare a slide for the microscopy practical?

Answer 25

1) add a drop of water to the middle of a clean slide
2) cut up an onion and use tweezers to peel of some tissue and put it into the water of the slide
3) Add a drop of iodine solution
4) Place a cover slip on top of the iodine and onion and try to not get any airbubbles

Question 26

How do you use the light microscope in the microscopy practical?

Answer 26

1) clip in the prepared slide onto the stage
2) select the lowest power objective lens first
3) look down the eyepiece lens
4) Turn the coarse adjustment knob to move the stage upwards and get the slide roughly in focus
5) Turn the fine adjustment knob to get a clear image of whats on the slide
6) Select the medium power objective lens and repeat steps 3 and 4

Question 27

How do you calculate percentage change?

Answer 27

Percentage change = final value - original value x100
Original value

Question 28

How do you do the osmosis practical?

Answer 28

1) You cut up a potatoe into identical cylinders and get some beakers with different sugar solutions in them ( 1 should be with water and another with a very concentrated sugar solution )

2) You measure the mass of the cylinders and then leave one cylinder in each beaker for 24h

3) Later, you take them out and dry them with a paper towel and measure their masses again

4) If the cylinders have drawn in water by osmosis, they’ll have increased in mass. If the water has been drawn out then they will have decreased in mass.

Question 29

What are root hair cells specialised to do?

Answer 29

They are specialised to have a higher surface area therefore water and minerals could be absorbed easyer

Question 30

What is active transport?

Answer 30

Active transport is the movement of dissolved molecules into or out of a cell through the cell membrane, from a region of lower concentration to a region of higher concentration. The molecules move against the concentration gradient , using energy released during respiration.

Question 31

What do you do to get from mm to um to nm

Answer 31

mm x1000 um x1000 nm

Question 32

What is the function of a Vacuole?

Answer 32

Stores cell sap

Question 33

What do chloroplasts do?

Answer 33

They contain chlorophyll which absorbs light needed for photosynthesis and is the place where photosynthesis happens which makes food for the plant.