2a

Question 1

What is the cell membrane?

Answer 1

Supports the cell and controls what goes in and out

Question 2

What is the nucleus?

Answer 2

Controls activity and contains genetic material

Question 3

What is the cytoplasm?

Answer 3

Site of chemical reactions which contains enzymes to control the reactions

Question 4

What is mitochondria?

Answer 4

Site of reactions for respiration

Question 5

What are the ribosomes?

Answer 5

Where proteins are made in the cell

Question 6

What is the cell wall?

Answer 6

Supports the cell and structures it

Question 7

What does the permanent vacuole contain?

Answer 7

Cell sap which is a weak solution of sugar and cells

Question 8

What are chloroplasts?

Answer 8

Where photosynthesis occurs and they contain chlorophyll

Question 9

What is the structure of a yeast cell?

Answer 9

Nucleus, cytoplasm, cell membrane and a cell wall

Question 10

What is the structure of a bacterial cell?

Answer 10

NO NUCLEUS! Cytoplasm, cell membrane, cell wall. The genetic material floats in the cytoplasm

Question 11

What is diffusion?

Answer 11

Spreading out of particles from an area of high concentration to an area of low concentration

Question 12

What do animal cells not have?

Answer 12

Cell wall, permanent vacuole and chloroplasts

Question 13

Where does diffusion happen?

Answer 13

In solutions and gases because the particles are free to move

Question 14

What affects the diffusion rate?

Answer 14

The bigger the difference in concentration the faster the diffusion rate

Question 15

What kind of molecules can diffuse through cell membranes?

Answer 15

Small molecules like oxygen, glucose, amino acids and water

Question 16

What can’t diffuse through cell membranes?

Answer 16

Big molecules such as starch and protein

Question 17

What is the overall movement called?

Answer 17

Net movement

Question 18

What are specialised cells?

Answer 18

Cells specialised for their function

Question 19

How is the palisade leaf cell adapted for photosynthesis?

Answer 19

1. Packed with chloroplasts, most are at the top closer to light
2. Tall shape resulting in large surface area for absorbing CO2
3. Thin so you can pack lots in a leaf

Question 20

What are guard cells adapted for?

Answer 20

To open and close pores

Question 21

How are guard cells adapted?

Answer 21

1. Kidney shape which opens and closes the stomach in a leaf
2. When the plant has lots of water the guard cells fill with it and go plump. This makes the stomata open for gas exchange for photosynthesis
3. When the plant doesn’t have much water the guard cells lose water and become flaccid which makes the stomach close. This prevents water vapour from escaping
4. Thin outer walls and thick inner walls make the opening and closing work
5. Sensitive to light and close at night to save water

Question 22

What are red blood cells adapted for?

Answer 22

To carry oxygen

Question 23

How are red blood cells adapted?

Answer 23

1. Big surface area for absorbing oxygen and to help them pass smoothly through capillaries
2. Packed with haemoglobin which absorbs oxygen
3. Have no nucleus for more room for haemoglobin

Question 24

What are sperm and egg cells specialised for?

Answer 24

Reproduction

Question 25

How are sperm and egg cells specialised?

Answer 25

1. The egg cell contains food reserves to feed the embryo 2. The eggs membranes structure changes when the sperm fuses with it to stop any more sperm getting in so the offspring ends up with the right amount of DNA 3. A sperm has a long tail and a streamlined head to help it swim to the egg 4. A sperm has a lot of mitochondria to give to energy to swim to the egg

Question 26

What is a tissue?

Answer 26

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

Question 27

What is an organ?

Answer 27

A group of different tissues that work together to perform a certain function

Question 28

What is an organ system?

Answer 28

A group of organs working together

Question 29

What is the stomach made up of?

Answer 29

1. Muscular tissue which moves the stomach wall to churn food 2. Glandular tissue which makes digestive juices to digest food 3. Epidermal tissue

Question 30

What is an organ system found in the human body?

Answer 30

Digestive system which breaks down food

Question 31

Name some plant organs

Answer 31

Stems, roots and leaves

Question 32

What are leaves made of?

Answer 32

1. Mesophyll tissue - where most of the photosynthesis takes place 2. Xylem and phloem - transport things such as water, mineral ions and sucrose around the plant 3. Epidermal tissue - covers the whole plant

Question 33

What is the photosynthesis equation?

Answer 33

SUNLIGHT Carbon dioxide + water ----------> glucose + oxygen CHLOROPHYLL

Question 34

What does photosynthesis produce?

Answer 34

Glucose and oxygen

Question 35

What is photosynthesis?

Answer 35

The process that produces glucose in plants and algae

Question 36

What factors affect the rate of photosynthesis?

Answer 36

Carbon dioxide, light and temperature

Question 37

What affects where organisms are found?

Answer 37

Environmental factors such as temperature and availability of water, nutrients, CO2 and O2 and amount of light

Question 38

How can you study the distribution of an organism?

Answer 38

Measure how common an organism is in two areas using quadrants Study how the distribution changes across an area by placing quadrants along a transect

Question 39

What is a quadrat?

Answer 39

A square frame enclosing a known area to compare how common an organism is in two sample area

Question 40

How do you calculate the mean number of organisms per quadrat?

Answer 40

Total number of organisms -------------------------------- Number of quadrats

Question 41

How do you calculate population size?

Answer 41

Multiply the mean number of organisms per metre squared and times it by the total area of the habitat

Question 42

What is a transect used for?

Answer 42

To study the distribution of organisms along a line

Question 43

How do you make your results more reliable?

Answer 43

Use a large sample size

Question 44

How can you improve the validity of your results?

Answer 44

Control the variables and use random samples

Question 45

How do plants use glucose?

Answer 45

``` For respiration Making cell walls Making proteins Stored in seeds Stored as starch ```