Organisms

Question 1

what are the levels of organisation?

Answer 1

organelle - nucleus
cell
tissue - group of similar cells working together for one job
organ - made up of tissues (heart)
organ system - made up of organs (digestive system)
organism - human being

Question 2

what is the function of a cell membrane?

Answer 2

controls what goes in and out of a cell

Question 3

what is the function of the cell wall?

Answer 3

protects and supports the cell

Question 4

what is the function of cytoplasm?

Answer 4

a clear jelly which contains many dissolved substances, especially proteins.

Question 5

what is the function of the nucleus?

Answer 5

stores DNA - powerhouse of the cell

Question 6

what is the function of mitochondria?

Answer 6

released energy from food

Question 7

what is the function of chloroplasts?

Answer 7

traps energy of sunlight

Question 8

what is the function of ribosome?

Answer 8

makes proteins

Question 9

what are the 3 methods of transportation between cells?

Answer 9

osmosis, diffusion and active transport

Question 10

what is diffusion?

Answer 10

the movement of molecules from an area of high concentration to an area of low concentration

Question 11

what is osmosis?

Answer 11

the movement of water molecules across a partially permeable membrane (cell membrane) from a high concentration of water to a low concentration of water.

Question 12

what is active transport?

Answer 12

the movement of molecules into cells against a concentration gradient (low to high concentration). It requires energy from respiration.

Question 13

describe the relationship between surface area and volume ratio

Answer 13

the more surface area - the faster the rate of movement into the cell

Question 14

how does distance affect diffusion?

Answer 14

the shorter the distance the faster the rate

Question 15

how does temperature affect diffusion?

Answer 15

at higher temperatures, diffusion is faster because the molecules have more kinetic energy

Question 16

how does the concentration gradient affect diffusion?

Answer 16

the greater the difference in diffusion (inside and outside the cell) the faster the diffusion rate (steep gradient - large difference)

Question 17

what is the practical to show osmosis?

Answer 17

h2o moves into the potato cells (potato in a water solution)
this increases the mass of the potato.
when the potato is in a strong sugar solution the water moves out of the cells by osmosis.

Question 18

name an example of diffusion

Answer 18

O2 from air into the blood

Question 19

what is the practical to show diffusion?

Answer 19

agar jelly with universal indicator.
then put acid on it.
universal indicator went red and we cut it in half to see how much it had diffused.

Question 20

name some examples of active transport

Answer 20

glucose form nephron back into the blood.

mineral ions from soil into root hair cells