B1

Question 1

how much can a light microscope magnify by

Answer 1

2000x

Question 2

how much can an electron microscope magnify by

Answer 2

20,000,000

Question 3

name some differences between the light microspoe and the electron microscope

Answer 3

light microscopes are cheap and can be used anywhere but electron microscopes are very expensive and have to be used in special environments.

Question 4

what is the formula to work out the magnification size

Answer 4

magnification=image size/size of real object

Question 5

what is a eukaryotic cell

Answer 5

animal and plant cells

Question 6

what is a prokaryotic cell

Answer 6

bacteria, they dont have a nucleus and the genetic info is free in the cytoplasm.

Question 7

what is the smallest type of unit

Answer 7

nano metre

Question 8

name 3 adaptions of the nerve cell

Answer 8

lot of dendrites to make connections to other nerve cells.
they have very long axons that carry nerve impulses from one part of your body to another( longest runs from base of spine to big toe)
nerve endings contain a lot of mitochondriato pass the impules to another cell or a musle.

Question 9

name the 3 adaptions of a muscle cell

Answer 9

they contain special proteins that contract when they slide over each other.They contain lots of mitochondria to transfer the energy needed to contract amd relax

Question 10

what is the flagella in a prokaryotic cell

Answer 10

a long protein strand that helps them move

Question 11

where is the DNA in a prokaryotic cell

Answer 11

floating around in the cytoplasm

Question 12

name 3 adaptions of a sperm cell

Answer 12

long tail to help the sperm swim towards the egg, full of mitochondria for it to transfer the energy needed to help the tail move, large nucleus for genetic info to be passed on.

Question 13

name 3 adaptations in root hair cells

Answer 13

greatly increased surface area for water to enter it, large vacuole to speed up osmosis, many mitochondria to transfer the energy needed for active transport

Question 14

name 3 adaptions of photosynthetic cells

Answer 14

they contain chloroplasts which trap the sunlight, placed in outer stem and leaves of plant so it can absorb as much sunlight as possible, it has a large permanent vacuole to keep the cell rigid during osmosis

Question 15

what does a xylem cell do

Answer 15

it cit carries water and mineral ions from roots to leaves and top of plant

Question 16

name 2 adaptions in xylem cells

Answer 16

they start off alive, but they then die and become hollow so water and ions can go through them, the spirals and rings of lignin keep it strong so it can stand the pressure of the water

Question 17

what does a phloem cell do

Answer 17

allows food to move up and down a plant

Question 18

name 2 adaptions of a phloem cell

Answer 18

cell walls between cells make sieve plates so water carrying dissolved food can move freely up and down the tubes, lose a lot of internal structures but have companion cells that keep them alive. The companion cells have a lot of mitochondria to transfer the energy needed to move dissolved food up and down the plant

Question 19

what is a solute

Answer 19

the thing that gets dissolved

Question 20

what is the solvent

Answer 20

the thing that does the dissolving

Question 21

what is diffusion

Answer 21

the spreading out of particals in a solution

Question 22

what is the net movement in diffusion

Answer 22

high to low concentration

Question 23

does diffusion occur up or down the concentration gradient

Answer 23

down

Question 24

what is gas exchange

Answer 24

where 2 gases move in opposite directions by diffusion

Question 25

how does the concentration gradient work

Answer 25

if there is a big difference in concentration between the 2 areas, the particles move quicker, meaning there is a steeper concentration gradient if there is only a small difference in concentration between the 2 areas then the gradient is shallower. Overall, the bigger the difference in concentration between the 2 areas, the quicker the particles move and the steeper the concentration gradient

Question 26

what is osmosis

Answer 26

the movement of water molecules from a dilute to a more concentrated solution through a partially permeable membrane that allows water to pass through

Question 27

what causes the water to move during osmosis

Answer 27

a difference in concentrations of solutions inside and outside of the cell

Question 28

does osmosis go up or down the concentration gradient

Answer 28

down

Question 29

if the concentration of solutes outside the cell is the same as inside the cell it is

Answer 29

isotonic

Question 30

if the concentration of solutes is higher outside the cell than inside it it is

Answer 30

hypertonic

Question 31

if the concentration of solutes is higher inside the cell than outside it it is

Answer 31

hypotonic

Question 32

why is osmosis important in plant cells

Answer 32

so it stays turgid

Question 33

does active transport go down or against a concentration gradient

Answer 33

against

Question 34

where does active transport move from and to

Answer 34

from a more dilute solution to a more concentrated solution

Question 35

where does active transport get the energy from to work

Answer 35

energy from food released in respiration

Question 36

what does active transport allow root hair cells to obtain

Answer 36

mineral ions that it needs from the ground against a concentration gradient

Question 37

where does active transport allow suger molecules to go

Answer 37

the gut. it goes from a low concentration of sugar molecules to a high one