B1 Cell Biology And Transport

Question 1

What are two types of eukaryotic cell?

Answer 1

animal and plant

Question 2

What type of cell are bacteria?

Answer 2

prokaryotic

Question 3

Where is DNA found in animal and plant cells?

Answer 3

in the nucleus

Question 4

What is the function of the cell membrane?

Answer 4

controls movement of substances in and out of the cell

Question 5

What is the function of mitochondria?

Answer 5

site of respiration to transfer energy for the cell

Question 6

What is the function of chloroplasts?

Answer 6

contain chlorophyll to absorb light energy for photosynthesis

Question 7

What is the function of ribosomes?

Answer 7

Enable production of proteins (protein synthesis)

Question 8

What is the function of the cell wall?

Answer 8

strengthens and supports the cell

Question 9

What is the structure of the main genetic material in a prokaryotic cell?

Answer 9

single loop of DNA

Question 10

How are electron microscopes different to light microscopes?

Answer 10

electron microscopes use beams of electrons instead flight, cannot be used to yievedmueahieherare
much more expensive, and have a much higher magnification and resolution

Question 11

What is the function of a red blood cell?

Answer 11

carries oxygen around the body

Question 12

Give three adaptations of a red blood cell.

Answer 12

no nucleus, contains a red pigment called haemoglobin, and has a bi-concave disc shape

Question 13

What is the function of a nerve cell?

Answer 13

carries electrical impulses around the body

Question 14

Give two adaptations of a nerve cell.

Answer 14

branched endings, myelin sheath insulates the axon

Question 15

What is the function of a sperm cell?

Answer 15

fertilises an ovum (egg)

Question 16

Give two adaptations of a sperm cell.

Answer 16

tail, contains lots of mitochondria

Question 17

What is the function of a palisade cell?

Answer 17

carries out photosynthesis in a leaf

Question 18

Give two adaptations of a palisade cell.

Answer 18

lots of chloroplasts, located at the top surface of the leaf

Question 19

What is the function of a root hair cell?

Answer 19

absorbs minerals and water from the soil

Question 20

Give two adaptations of a root hair cell.

Answer 20

long projection, lots of mitochondria

Question 21

What is diffusion?

Answer 21

net movement of particles from an area of high concentration to an area of low concentration along a concentration gradient - this is a passive process (does not require energy from respiration)

Question 22

Name three factors that affect the rate of diffusion.

Answer 22

concentration gradient, temperature, membrane surface area

Question 23

How are villi adapted for exchanging substances?

Answer 23

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

Question 24

How are the lungs adapted for efficient gas exchange?

Answer 24

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

Question 25

How are fish gills adapted for efficient gas exchange?

Answer 25

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

Question 26

What is osmosis?

Answer 26

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

Question 27

Give one example of osmosis in a plant.

Answer 27

water moves from the soil into the root hair cell

Question 28

What is active transport?

Answer 28

movement of particles against a concentration gradient - from a allute solution to a more concentrated solution - using energy from respiration

Question 29

Why is active transport needed in plant roots?

Answer 29

concentration of mineral ions in the soil is lower than inside the root hair cells - the mineral ions must move against the concentration gradient to enter the root hair cells

Question 30

What is the purpose of active transport in the small intestine?

Answer 30

Allows sugars to be absorbed even though the concentration of sugar in the small intestine is lower than the concentration of sugar in the blood