B1: Cells And Organisation🧫

Question 1

1mm = ???? μm

Answer 1

1000

Question 2

1 μm = ???? nm

Answer 2

1000

Question 3

Describe the “ IAM” triangle.

Answer 3

I
A M

I= image size
A= actual size
M= magnification

Question 4

What is the purpose of the nucleus?

Answer 4

It controls all activities of the cell. It contains genes and chromosomes.

Question 5

What is the cytoplasm?

Answer 5

A gel which the organelles are suspended in. Most chemical reactions happen in the cytoplasm.

Question 6

What is the cell membrane?

Answer 6

Controls what comes in and out of the cell.

Question 7

What are the mitochondria?

Answer 7

Where aerobic respiration takes place.

Question 8

What are ribosomes?

Answer 8

Where protein synthesis takes place (making all the proteins that the cell needs).

Question 9

What are chloroplasts?

Answer 9

They contain chlorophyll. Chlorophyll absorbs light so photosynthesis can happen.

Question 10

What is a vacuole?

Answer 10

They keep the cells rigid by being filled with sap.

Question 11

Give two examples of eukaryotic cells?

Answer 11

Animal and plant cells.

Question 12

What are prokaryotic cells?

Answer 12

They consist of cytoplasm and a cell membrane with a cell wall. Genetic material is in a single loop.

Question 13

Give an example of prokaryotic cells.

Answer 13

Bacteria

Question 14

Name 2 nerve cells adaptations.

Answer 14

Lots of dendrites to make connections to other cells. A long axon to carry the nerve impulse.

Question 15

Name 3 muscle cell adaptations.

Answer 15

Special proteins that slide over each other, making fibres contract.
They contain mitochondria to transfer energy needed for contractions.
They can store glycogen for energy.

Question 16

Name 4 sperm cell adaptations.

Answer 16

A long tail to help sperm move quickly. Lots of mitochondria for energy.
The acrosome stored digestive enzymes.
A large nucleus contains genetic info to be passed on.

Question 17

Name 3 adaptations of root hair cells.

Answer 17

Increased surface area for water to move into the cell.
A large vacuole to speed up movement of osmosis from soil to root hair cell.
Many mitochondria to transfer energy for active transport.

Question 18

Name 2 adaptations of xylem cells.

Answer 18

They are alive at first but have lignin which builds up in spirals in the walls.
The spirals of lignin make the strong and help support the plant stem.

Question 19

Name 2 adaptations of phloem cells.

Answer 19

They have sieve plates which allow water carrying dissolved food to move freely up and down the tube.
They lose a lot of their internal structure so have many companion cells to keep them alive.

Question 20

What is diffusion?

Answer 20

The spreading out of the particles of a gas or any substance in a solution.

Question 21

What is the rate of diffusion affected by? (3)

Answer 21

Difference in concentrations, temperature and available surface area.

Question 22

What is osmosis?

Answer 22

Where only water moves across a partially permeable membrane from a dilute solution to a concentrated solution.

Question 23

What does isotonic mean?

Answer 23

If the concentration outside of a cell is THE SAME as the internal concentration.

Question 24

What does hypertonic mean?

Answer 24

Where the concentration outside the cell is HIGHER than inside the cell.

Question 25

What does hypotonic mean?

Answer 25

Where the concentration outside the cell is LOWER than inside the cell.

Question 26

When the vacuole swells due to water moving into plant cells, what is the pressure that it causes called?

Answer 26

Turgor

Question 27

What is active transport?

Answer 27

When substances have to move against a concentration gradient across a partially permeable membrane.

Question 28

Name 4 adaptations for exchanging materials.

Answer 28

Having a large surface area.
Having a thin membrane.
Having efficient bloody supply.
Being ventilated (gas exchange).