B1 - Cell structure and transport

Question 1

What type of cell are bacteria

Answer 1

prokaryotic

Question 2

Two types of eukaryotic cell

Answer 2

plants and animals

Question 3

function of cell membrane

Answer 3

controls movement of substances in and out of the cell

Question 4

function of mitochondria

Answer 4

site of respiration to transfer energy to the cell

Question 5

function of chloroplasts

Answer 5

contain chlorophyll to absorb light energy for photosynthesis

Question 6

function of ribosomes

Answer 6

enable protein synthesis (production of proteins)

Question 7

function of cell wall

Answer 7

strengthens and supports the cell

Question 8

Genetic material in a prokaryotic cell

Answer 8

single loop of DNA

Question 9

Pros and cons of electron microscope

Answer 9

• beams of electrons instead of light
• cannot view living samples
• very expensive
• higher magnification and resolution

Question 10

function of red blood cell

Answer 10

carries oxygen around the body

Question 11

three adaptations of red blood cell

Answer 11

• no nucleus - contains more oxyhaemoglobin
• haemoglobin - binds to oxygen
• bi-concave disc - maximises surface area

Question 12

function of nerve cell

Answer 12

carries electrical impulses around the body

Question 13

two adaptations of nerve cell

Answer 13

• branched endings - can make connections with other nerve cells
• myelin sheath on axon - speeds up transmission of impulses

Question 14

function of sperm cell

Answer 14

fertilises ovum (egg)

Question 15

two adaptations of sperm cells

Answer 15

• tail - can swim through uterus
• lots of mitochondria - lots of respiration so lots of energy for swimming long distances

Question 16

function of palisade cell

Answer 16

carries out photosynthesis in leaf

Question 17

two adaptations of palisade cell

Answer 17

• lots of chloroplasts - lots of photosynthesis for food
• located at top of leaf - most sunlight

Question 18

function of root hair cell

Answer 18

absorbs minerals and water from the soil

Question 19

two adaptations of root hair cell

Answer 19

• long projection - lots can fit together to maximise surface area to volume ratio
• lots of mitochondria - lots of respiration so energy for active transport to get minerals out of soil

Question 20

Define diffusion

Answer 20

Net movement of particles from an area of higher concentration to an area of lower concentration along the concentration gradient. Passive process.

Question 21

three factors that affect diffusion

Answer 21

• concentration gradient
• temperature
• membrane surface area

Question 22

How are villi adapted for exchanging substances?

Answer 22

• long and thin - increase surface area
• one-cell thick membrane - short diffusion pathway
• good blood supply - maintain steep concentration gradient

Question 23

How are lungs adapted for gas exchange?

Answer 23

• alveoli - large surface area
• moist membranes - increase rate of diffusion
• one-cell membranes - short diffusion pathway
• good blood supply - maintains steep concentration gradient

Question 24

How are fish gills adapted for efficient gas exchange?

Answer 24

• large surface area for gases to diffuse across
• thin layer of cells - short diffusion pathway
• good blood supply - maintain steep concentration gradient

Question 25

Define osmosis

Answer 25

Diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.

Question 26

Give example of osmosis in a plant

Answer 26

Water moves from soil into root hair cell

Question 27

Define active transport

Answer 27

Movement of particles from an area of lower concentration to an area of higher concentration using energy from respiration.

Question 28

Why is active transport needed in plant roots?

Answer 28

Concentration of mineral ions in the soil is lower than the concentration inside the root hair cells so mineral ions have to move against the concentration gradient to enter.

Question 29

Why is active transport needed in the small intestine?

Answer 29

So sugars can be absorbed when the concentration of sugar in the small intestine is lower than the concentration of sugar in the blood.