cells ✓

Question 1

what is the acronym for the characteristics of living organisms ?

Answer 1

MRS GREN

Question 2

what does MRS GREN stand for ?

Answer 2

Movement 
Respiration
Sensitivity
Growth 
Reproduction
Excretion
Nutrition

Question 3

what do living organisms do to their environment ?

Answer 3

they control it

Question 4

put these words in order of smallest to largest

organisms organelle organs cell tissue organ systems

Answer 4

organelle 
cell 
tissue
organs 
organ systems 
organism

Question 5

what does tissue mean ?

Answer 5

a group of similar cells that work together to carry out a particular function

Question 6

what does organ mean ?

Answer 6

is a group of different tissues that work together to perform a function

Question 7

what are the similarities and differences between plant and animal cells ?

Answer 7

• animal cells have small vacuoles whereas the plant cells have large ones
• plants have chloroplasts but animal cells don’t
• plants have a cell wall but animal cells don’t

Question 8

what is diffusion ?

Answer 8

movement of a substance from an area of high concentration to an area of low concentration

Question 9

what is osmosis ?

Answer 9

is the diffusion of water molecules from a dilute solution to a more concentrated solution

Question 10

what is a partially permeable membrane ?

Answer 10

allows some particles to pass through but not all particles

Question 11

what is the affect of distance on the diffusion rate ?

Answer 11

the shorter the distance for diffusion the faster the rate

Question 12

what is the affect of concentration gradient on the diffusion rate ?

Answer 12

the greater the difference between the concentration inside and outside the cells the faster the diffusion rate

Question 13

what is the affect of surface area on the diffusion rate ?

Answer 13

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

Question 14

what is the affect of temperature on the diffusion rate ?

Answer 14

at a higher temperature diffusion is faster - molecules have more kinetic energy to move

Question 15

what is the affect of volume ratio on the diffusion rate ?

Answer 15

as the surface area to volume ratio gets smaller it takes longer to diffuse

Question 16

describe an experiment on osmosis

Answer 16

• get two Petri dishes
• get 2 thin slices of potato and 2 thin slices of cucumber
• put a slice of potato and a slice of cucumber in each dish
• pour pure water into one of the Petri dishes and a salt solution into the other one

Question 17

what would the results of the osmosis experiment be ?

Answer 17

cucumber and potato in water would be harder and more sturdy, they were saturated because they took in water
cucumber and potato in the salt solution would be softer and more floppy because they lost water due to the salt solution

Question 18

describe an experiment on diffusion

Answer 18

• get a piece of card
• draw a line near the bottom of the card
• draw coloured dots on the line
• put the card in some water below the line
• wait to see the colours have risen up the card

Question 19

what is the process of active transport ?

Answer 19

is the process by which dissolved molecules move across a cell membrane from a lower to a higher concentration

Question 20

what are the differences between active transport osmosis and diffusion ?

Answer 20

• active transport requires energy from a cell

- osmosis and diffusion have passive transport