B1

Question 1

What is a eukaryotic cell?

Answer 1

A cell with a nucleus. Plant and animal cells are eukaryotic.

Question 2

What is a prokaryotic cell?

Answer 2

A small cell without a nucleus, it has a large ring of genetic information with other smaller plasmids around the cell. Bacterial cells are prokaryotic.

Question 3

What organelles are in an animal cell?

Answer 3

A nucleus, cytoplasm, cell membrane, mitochondria and ribosomes.

Question 4

What extra organelles do plant cells have?

Answer 4

A cell wall, a permanent vacuole and chloroplasts.

Question 5

What is the function of the nucleus?

Answer 5

The nucleus holds genetic info and controls the activities of the cell.

Question 6

What is the function of the cytoplasm?

Answer 6

The cytoplasm is where most chemical reactions of the cell occur.

Question 7

What is the function of the cell membrane?

Answer 7

The cell membrane controls what goes in and out of the cell.

Question 8

What is the function of the mitochondria?

Answer 8

The mitochondria releases energy through aerobic respiration.

Question 9

What is the function of the ribosomes?

Answer 9

The ribosomes produce proteins via protein synthesis.

Question 10

What is the function of a cell wall?

Answer 10

The cell wall maintains the shape of the cell and prevents the bursting of the cell. It is made from cellulose.

Question 11

What is the function of the permanent vacuole?

Answer 11

The permanent vacuole holds cell sap

Question 12

What is the function of the chloroplasts?

Answer 12

The chloroplasts contain chlorophyll that absorbs light for photosynthesis. Photosynthesis happens here.

Question 13

What is magnification?

Answer 13

How much bigger an object appears compared to it’s actual size.

Question 14

What is resolution?

Answer 14

Resolution is how well you can distinguish between 2 objects close together (How detailed it is)

Question 15

Magnification Formula

Answer 15

Magnification = Image size/ Actual size

Question 16

Electron microscopes compared to Light microscopes?

Answer 16

Electron microscopes have a higher resolution and a higher magnification than light microscopes.

Question 17

Conversion rates

Answer 17

nm –> um –> mm –> m –> km
Each increase is multiplying it by 1000.

Question 18

What is a specialised cell?

Answer 18

A cell that is made for a certain specific function, it is developed in an organism over many years of evolution.

Question 19

How are sperm cells adapted?

Answer 19

Half the chromosomes so in fusion the embryo has 46 chromosomes. They have lots of mitochondria to move quickly.
Acid in head so it can break down the walls of the egg.
Has a flagellum (tail).

Question 20

How is a nerve cell adapted?

Answer 20

Nerve cells have a myelin sheath which acts as insulation so impulses travel faster. Lots of branches so can connect to lots of other nerve cells. Dendrites with protein receptors.

Question 21

How is a muscle cell adapted?

Answer 21

Muscle cells have lots of mitochondria for contracting and moving the bones.

Question 22

How is a root hair cell adapted?

Answer 22

Root hair cells have lots of mitochondria for active transport, large surface area due to the shape for high absorbtion rate. No chloroplasts.

Question 23

How is the xylem adapted?

Answer 23

The xylem is made up of dead cells so that they don’t absorb any water. They don’t have walls to form a hollow tube for the water.

Question 24

How is the phloem adapted?

Answer 24

They have sieve plates which are holes in the end of cell walls forming tubes the sugar and amino acids to get through.

Question 25

What is diffusion?

Answer 25

The net movement of particles from a high to low concentration

Question 26

Give examples of diffusion

Answer 26

Oxygen and carbon dioxide between the cells and blood. Urea from cells to the plasma in the kidneys in excretion.

Question 27

What 3 factors affect the rate of diffusion?

Answer 27

Difference in concentration (concentration gradient) The temperature The surface area

Question 28

What is osmosis?

Answer 28

The net movement of water particles from a dilute to concentrated solution through a partially permeable membrane.

Question 29

What will happen if the concentration outside a cell is higher than inside?

Answer 29

If the concentration outside is higher then the water will leave the cell causing the cell to shrivel.

Question 30

What will happen if the concentration inside a cell is higher than the outside?

Answer 30

If the concentration inside is higher than the water will come into the cell causing it to swell.

Question 30

What is active transport?

Answer 30

The net movement of particles from a low to high concentration through the use of energy.

Question 31

Give an example of active transport

Answer 31

In root hair cells active transport is used to move mineral ions from the soil into the cell. In the small intestine, active transport is used to move sugar into the blood.

Question 32

Why can a single celled organism transport molecules in and out of itself easily?

Answer 32

It has a high surface area to volume ratio.

Question 33

Why do multicellular organism have difficulty exchanging with the environment?

Answer 33

They have small surface area to volume ratios. This means they need specialised systems to obtain the molecules they need to survive.

Question 34

How are exchange surface areas adapted for exchanging materials?

Answer 34

They’re thin - so substances only have a short distance to diffuse They have a large surface area - so lots of a substance can diffuse at once They maintain a concentration gradient (e.g. by having a good blood supply) - so that substances keep diffusing in the right direction. They are often moist.