B1

Question 1

What does magnification mean?

Answer 1

How much bigger a sample appears to be under the microscope than it is in real life

Question 2

What does resolution mean?

Answer 2

The ability of a microscope to distinguish fine details and differentiate between two very close objects

Question 3

Formula linking magnification, image size and real size

Answer 3

Magnification = Image Size ÷ Actual Size

Actual Size = Image Size ÷ Magnification

Image Size = Actual Size x Magnification

Question 4

Number of micrometers (µm) in a millimeter (mm)?

Answer 4

1000 micrometers in a millimeter

Question 5

Number of nanometers (nm) in a micrometer (µm)?

Answer 5

1000 nanometers in a micrometer

Question 6

Organelles in an animal cell

Answer 6

Nucleus, Cell membrane, Cytoplasm, Mitochondria and Ribosomes

Question 7

Extra Organelles in plant cells

Answer 7

Cell Wall, Chloroplasts, Permanent Vacuole

Question 8

Function of a nucleus

Answer 8

Directs all the cells activities; contains the cells DNA

Question 9

Function of cell membrane

Answer 9

regulates what enters and leaves the cell

Question 10

Function of cytoplasm

Answer 10

Where chemical reactions take place

Question 11

Function of mitochondria

Answer 11

Powerhouse of the cell; Where respiration occurs

Question 12

Function of Ribosomes

Answer 12

Where protein are synthesised

Question 13

Function of Chloroplasts

Answer 13

Site of photosynthesis; contains Chlorophyll - a green pigment

Question 14

Function of Cell Wall

Answer 14

Protects, strengthens and supports the cell

Question 15

Function of Vacuole

Answer 15

Filled with cell sap which helps keep the cell turgid

Question 16

What are the two types of cells?

Answer 16

Prokaryotes and Eukaryotes

Question 17

What are prokaryotic cells?

Answer 17

Bacterial cells; Cells without a nucleus

Question 18

What are eukaryotic cells?

Answer 18

Cells with a nucleus and organelles

Question 19

What is differentiation?

Answer 19

The process by which a cell changes to become specialised for its job

Question 20

Function of root hair cells

Answer 20

To absorb water and mineral ions for the plant via osmosis

Question 21

Adaptation of root hair cells

Answer 21

1. Large surface area for water to move up the cell
2. Have lots of mitochondria which release energy from glucose needed for active transport of mineral ions into the cell
3. Have a large permanent vacuole that speeds up the movement of water by osmosis

Question 22

Function of sperm cells

Answer 22

Contains genetic information in the nucleus; needed for fertilisation to occur

Question 23

Adaptation of sperm cell?

Answer 23

1. It has a long tail and a streamlined head to help it swim to the egg
2. There are lots of mitochondria in the cell to provide the energy needed.
3. It also carries enzymes in its head to digest through the egg cell membrane.

Question 24

Function of nerve cells

Answer 24

To carry electrical impulses around the body

Question 25

Adaptation of nerve cell

Answer 25

1. Thin, long branches to carry impulses all around the body
2. Branched connections at each end to allow electrical impulses to pass to other cells

Question 26

What is diffusion?

Answer 26

The movement of particles from an area of high concentration to an area of low concentration; results in an equilibrium of particles; DOWN a concentration gradient; no energy needed (passive)

Question 27

Where does diffusion occur?

Answer 27

Gas exchange in the lungs

Question 28

What is osmosis?

Answer 28

Diffusion of WATER molecules across a partially permeable membrane (cell membrane) from an area of high to low concentration; DOWN a concentration gradient; no energy needed (passive)
Water molecules have an overall net movement if an area has a stronger concentration of solutes (salts dissolved in water)

Question 29

Where does osmosis occur?

Answer 29

1. Root hair cells (plants)
2. Water going into blood in the intestines

Question 30

What does turgid mean?

Answer 30

When cell walls become rigid due to high water content

Question 31

What does hypertonic mean?

Answer 31

higher solute concentration, lower water concentration in a solvent

Question 32

What does hypotonic mean?

Answer 32

lower solute concentration, higher water concentration in a solvent

Question 33

What does isotonic mean?

Answer 33

equal solute and water concentration in a solvent

Question 34

What is active transport?

Answer 34

The movement of ions or molecules across a partially permeable membrane (cell membrane) from a region of lower concentration to a region of high concentration; AGAINST a concentration gradient; requires energy from respiration (active)

Question 35

Where does active transport occur?

Answer 35

1. In root hair cells, moving mineral ions and water from the soil and into the plant
2. In the gut where there is a lower concentration of nutrients in the gut and a higher concentration in the blood.

Question 36

How does exchange occur?

Answer 36

1. Diffusion
2. Osmosis
3. Active transport

Question 37

Describe how a small object effects the relationship between surface area to volume ratio?

Answer 37

The SMALLER the object, the HIGHER the SA : V

• Shorter diffusion distance = more sufficient for exchanging materials

Question 38

Describe how a large object effects the relationship between surface area to volume ratio?

Answer 38

The LARGER the object, the SMALLER the SA : V

• Larger diffusion distance = less sufficient for exchanging materials

Question 39

What makes a good exchange surface?

Answer 39

• Large surface area
• Thin membrane surface
• Rich blood supply (maintaining steep concentration gradients)