Topic 1 - Cell Biology

Question 1

What are eukaryotic cells?

Answer 1

They have a nucleus.

Question 2

What are prokaryotic cells?

Answer 2

Don’t have a nucleus.

Question 3

Examples of eukaryotic cells?

Answer 3

Animal cells
Plant cells

Question 4

Examples of prokaryotic cells?

Answer 4

Bacteria

Question 5

What does the nucleus do?

Answer 5

Controls the activities of the cell and contains DNA.

Question 6

What does the cell membrane do?

Answer 6

Controls what goes in and out of the cell.

Question 7

What does the mitochondria do?

Answer 7

Releases energy by aerobic respiration.

Question 8

What do the ribosomes do?

Answer 8

Where protein synthesis occurs.

Question 9

What does the cytoplasm do?

Answer 9

Where chemical reactions take place.

Question 10

What do the chloroplasts do?

Answer 10

Where photosynthesis takes place.

Question 11

What does the vacuole do?

Answer 11

Keeps the cell rigid for support and stores sap.

Question 12

What does the cell wall do?

Answer 12

Made of cellulose for support and to stop the cell bursting.

Question 13

What does genetic material (chromosomal DNA) do?

Answer 13

Contains the majority of the bacterias genes and controls most of the cells activities.

Question 14

What do the plasmids do?

Answer 14

Contain some genes and control some of the cells activity.

Question 15

What does the flagella do?

Answer 15

Move to propel the cell.

Question 16

What’s the role of the sperm cell?

Answer 16

Fertilise the egg cell

Question 17

What does the sperm cell contain?

Answer 17

Haploid nucleus - 23 chromosomes
Tail - swim to egg
Acrosome - break down outer membrane of egg
Mitochondria - releases energy so sperm can reach egg

Question 18

What does the egg cell contain?

Answer 18

Large nutrient rich cytoplasm - nourish developing embryo
Cell membrane - changes structure after fertilisation to ensure no other sperm can penetrate egg
Haploid nucleus - 23 chromosomes

Question 19

What does the ciliated epithelial cell contain?

Answer 19

Cilia - hair like projections to sweep mucus or the egg cell
Nucleus

Question 20

Advantages of electron microscopes?

Answer 20

Magnify up to 500000 x
Extremely high resolution
Possible to investigate a greater field depth

Question 21

Disadvantages of electron microscope?

Answer 21

Very expensive
Specimens must be fixed in a vacuum and therefore dead
Requires specialist training to use

Question 22

Definition of resolution

Answer 22

The smallest distance between 2 points that can be seen as 2 points.

Question 23

Unit of measurement conversions?

Answer 23

Centimetre
Millimetre
Micrometer
Nanometer
Picometer

X10
X1000
X1000

Question 24

Total magnification calculation

Answer 24

Eyepiece lens X objective lens magnification

Question 25

Magnification equitation

Answer 25

Image size / actual size

Question 26

What are enzymes?

Answer 26

Biological catalysts that speed up the rates of reaction. They are proteins. They can break down/build up or change.

Question 27

What is the substrate?

Answer 27

Molecule changed in the reaction.

Question 28

What factors affect enzymes?

Answer 28

Temperature Ph Substrate concentration

Question 29

What are proteins broken down by and into?

Answer 29

Protease Amino acids

Question 30

What are carbohydrates broken down by and what into?

Answer 30

Carbohydrase (amylase) Simple sugars and glucose

Question 31

What are lipids broken down by and into?

Answer 31

Lipase Fatty acids + glycerol

Question 32

What is diffusion?

Answer 32

Diffusion is the passive movement of molecules from an area of high concentration of that molecule, to an area of low concentration of that molecule (down the concentration gradient). Diffusion only occurs in liquids and gases.

Question 33

What is osmosis?

Answer 33

Osmosis is the passive movement of water molecules from an area of high water concentration, to an area of low water concentration (down the concentration gradient), through a partially permeable membrane.

Question 34

What does hypertonic mean?

Answer 34

High solute concentrate (low water concentration)

Question 35

What does hypotonic mean?

Answer 35

Low solute concentration (high water concentration)

Question 36

What does isotonic mean?

Answer 36

The same solute concentration either side of the membrane.

Question 37

Features of a microscope

Answer 37

• Coarse focus wheel • Fine focus wheel • Eyepiece lens - magnifies the image • Objective lens - change the magnification

Question 38

Active transport

Answer 38

Active transport is the movement of molecules from an area of low concentration, to an area of high concentration (against the concentration gradient), requiring energy from respiration.

Question 39

What will happen to iodine if the starch has not been broken down yet?

Answer 39

It will be black. When broken down it will be orange.