ch 3

Question 1

similarties between animal and plant cells [4]

Answer 1

-cell membrane
-cytoplasm
-nucleus
-mitochondria

Question 2

differences between animal and plant cells [4]

Answer 2

-plant cell has cell wall
-plant cell has chloroplasts
-plant cell has a single big vacuole but animal cell has multiple small vacuoles
-plant cell has starch as stored food but animal cell stores food as glycogen

Question 3

function of cell membrane

Answer 3

-control exchange of substances in and out of the cell

Question 4

function of cytoplasm [2]

Answer 4

-container for all cell organelles
-site for all chemical reactions

Question 5

function of nucleus [2]

Answer 5

-contain genetic material
-control cell division

Question 6

function of mitochondria

Answer 6

aerobic respiration and production of energy

Question 7

what is the plant cell wall made of

Answer 7

made of cellulose fibres which are tough and strong

Question 8

function of cell wall [2]

Answer 8

-support and protect the plant cell
-prevent cell bursting

Question 9

what does the chloroplast contain?

Answer 9

green pigment, chlorophyll

Question 10

function of chloroplasts

Answer 10

absorb sunlight in photosynthesis to produce glucose

Question 11

function of the vacuole [2]

Answer 11

-food storage
-water storage

Question 12

what does the vacuole contain

Answer 12

cell sap

Question 13

why is the inner membrane of the mitochondria folded ?

Answer 13

• to increase surface area

Question 14

what is mitochondria

Answer 14

a very small organelle, that can only be seen by an electronic microscope

Question 15

why do active cells have a big number of mitochondria

Answer 15

to make more respiration and produce more energy

Question 16

3 examples of active cells

Answer 16

• muscle cell
  -sperm cell
  -nerve cell

Question 17

what are the 3 tiny organelles that can only be seen by an electronic microscope

Answer 17

• endoplasmic reticulum
  -ribosomes
  -mitochondria

Question 18

what is endoplasmic reticulum ?

Answer 18

channels inside the cytoplasm, that some ribosomes attach to (internal transport system)

Question 19

function of ribosomes

Answer 19

protein synthesis

Question 20

why does root hair cell not have any chloroplasts

Answer 20

it is present below soil surface in the darkness

Question 21

function of the root hair cell [2]

Answer 21

-absorbtion of water by osmosis
-absorbption of minerals by active uptake

Question 22

how is the root hair cell adapted to its function [3]

Answer 22

-finger-like projection: to increase surface area of absorbtion
-concentrated cell sap: to absorb water by osmosis
-much mitochondria : to produce energy to absorb minerals by active uptake

Question 23

what are xylem vessels [2]

Answer 23

-thin, long and hollow tubes extending from the root to the stem to the leaves
-water-conducting tissue

Question 24

functions of xylem vessels [2]

Answer 24

• transport water and minerals from the soil up to the leaves
  -support the plant

Question 25

adaptations of xylem vessel to its function [3]

Answer 25

-thin, long hollow tubes with no cytoplasm and no organelles to allow easy passage of water from below up -thick cell wall, made of cellulose and lignin to support the plant -cells joined end-to-end with no cross walls , to form a long continous tubes

Question 26

function of red blood cell

Answer 26

carry oxygen from lungs to all tissue

Question 27

adaptation of RBC to its function [3]

Answer 27

-RBC had no nucleus : to give space for haemoglobin -RBC contain haemoglobin : a protein which binds to oxygen and carry it to all tissue -biconcave disc shape : to increase surface area of oxygen uptake

Question 28

function of palisade cell

Answer 28

photosynthesis (using light CO2 to produce food)

Question 29

adaptation of palisade cell to its function [3]

Answer 29

-thin moist cell wall: to allow easy passage of CO2 into the cell by diffusion -large number of chloroplasts that are arranged close to cell wall: to absorb as much light as possible -expanded vacuole : to push chloroplasts towards cell wall , nearer to light

Question 30

3 cells without nucleus

Answer 30

- bacterial cell -RBC -xylem cell

Question 31

2 cells with large surface area

Answer 31

- root hair cell -red blood cell

Question 32

which cell is dead

Answer 32

xylem cells

Question 33

define cell

Answer 33

it is the building unit of the living organism

Question 34

define tissue

Answer 34

it is a group of cells having the same structure and function

Question 35

define organ

Answer 35

it is a group of tissues grouped together to do a specific function

Question 36

define organ system

Answer 36

it is a group of organs grouped together to do a specific function

Question 37

how does a light microscope work [4]

Answer 37

-by a beam of light -focused by glass lenses -gives coloured images -has lower magnification

Question 38

how does an electronic microscope work [4]

Answer 38

- a beam of electrons is used -focused by electro-magnets -black and white images -higher magnification

Question 39

how is magnification calculated

Answer 39

image/ actual