Chapter 1 - Cells And Organisation

Question 1

How do you calculate total magnification?

Answer 1

Eyepiece lens x objective lens

Question 2

Define the term resolution

Answer 2

Resolution is the ability to distinguish between two separate points in an image.

Question 3

What is the role of the nucleus?

Answer 3

Contains DNA in the form of chromosomes. Contains the genetic code.

Question 4

What is the role cytoplasm in a cell?

Answer 4

This is where chemcial reactions take place.

Question 5

What is the function of the cell membrane?

Answer 5

Controls what enters and leaves the cells.

Question 6

What is function of the mitochondria is cells?

Answer 6

This is the site of respiration.

Glucose + Oxyen –> Carbon dioxide + water vapour + ATP energy

Question 7

Define the word ‘magnification’

Answer 7

Magnification is how much bigger an image is compared to it’s actual size.
Can be calculated by using the IAM triange.

Question 8

What is the IAM triangle?

Answer 8

The way to find out the image, actual size and magnification.

Question 9

Function of the cellulose cell wall

Answer 9

This is outer layer of plant cells. It is made of cellulose. It gives the plant strength and support.

Question 10

Why are ribosomes needed in a cell?

Answer 10

Ribosomes are the site (location) where proteins are made.

Question 11

What is the function of chloroplasts in plant cells?

Answer 11

Chloroplasts contain a green chemcial called chlorophyll. It traps sunlight energy which is needed for photosynthesis.

Question 12

What is the function of the vacuole?

Answer 12

A space in the cytoplasm filled with cell sap. This is important for keeping the cells rigid to support the plant.

Question 13

What is an Eukaryotic cell?

Answer 13

A cell that has a nucleus, organelles and has membranes around it.

Question 14

What are prokaryotic cells?

Answer 14

Cells that don’t have a nucleus or organelles.

Question 15

What is a plasmid?

Answer 15

A strand of DNA which is in the cytoplasm.

Question 16

What is the order of magnitude?

Answer 16

Div 1000 div 1000 div 10 div100 div100
nm um mm cm m km
x 1000 x 1000 x 10 x 100 x1000

Question 17

Nerve cell adaptations

Answer 17

It is very long so it can work with other parts in your body.

Question 18

Muscle cell adaptations

Answer 18

There is a lot of mitochondria. Therefore it can release energy for contractions.

Question 19

Sperm cell adaptations

Answer 19

A tail so it can move, to the egg. The head has the DNA and genes and also has an enzyme. Therefore it can penetrate the egg.

Question 20

Root hair cell adaptations

Answer 20

Large surface area so osmosis can happen quicker. Has more mitochondria to give more energy for active transport.

Question 21

What is active transport?

Answer 21

The process by which molecules move from an area of low concentration to an area of higher concentration.

Question 22

What are xylem cells?

Answer 22

It takes water and minerals to provide help for soft tissues.

Question 23

What are phloem cells?

Answer 23

It conducts sugars and other products which are downwards from the leaves.

Question 24

What is diffusion?

Answer 24

The net random movement of particles from an area of high concentration to low concentration.

Question 25

What is the rate of diffusion?

Answer 25

The rate of diffusion increases when the surface area of the membrane is greater, the shorter the distance that the particles have to move, if the temperature increases or when the greater the difference in concentration.

Question 26

What is dilute?

Answer 26

When there is more water molecules and less solute e.g. salt, sugar and ribena.

Question 27

What is concentrated?

Answer 27

When there is more solute and less water molecules.

Question 28

What is osmosis?

Answer 28

The movement of water molecules from an area of high concentration to an area of low concentration, across a partially permeable membrane. This is a passive process.

Question 29

What is crenated?

Answer 29

It's when cells shrink because the solution around it is hypertonic to the cytoplasm.

Question 30

What is lysis?

Answer 30

When the cell membrane bursts because of osmosis bringing water into the cell.

Question 31

How is a cell plasmolyse?

Answer 31

When the cell shrinks because of losing water from osmosis. This causes gaps between the cell wall and membrane.

Question 32

What is turgid?

Answer 32

When a plant cell is filled up with water

Question 33

What is turgor pressure?

Answer 33

The pressure of the water pushing the plasma membrane in to the cell wall.

Question 34

What is interphase?

Answer 34

The first stage of the cell cycle. The cell prepares itself to divide. The DNA is replicated and organelles make copies of themselves.

Question 35

What is mitosis?

Answer 35

The second stage of the cell cycle. The chromosomes line up along the centre of the cell and get pulled to opposite ends. The nucleus divides.

Question 36

What is cytokinesis?

Answer 36

The third stage of the cell cycle. The cytoplasm and cell membrane divide. Two new identical cells are formed.

Question 37

What is chromosomes?

Answer 37

They hold genetic information and are found in the nucleus.

Question 38

What are differentiated cells?

Answer 38

When a cell becomes specialised.

Question 39

What are undifferentiated cells?

Answer 39

They are stem cells which are able to become specialised.

Question 40

What are embryonic stem cells?

Answer 40

They are stem cells found in embryos and can develop into almost every cell type.

Question 41

What are adult stem cells?

Answer 41

They are stem cells found in adult tissues (such as bone, marrow, brain, muscle and liver stem cells). These cells can only change into the same type of cell as the tissue they came from.