Exam Revision

Question 1

B1: What are eukaryotic cells?

Answer 1

Cells from eukaryotes that have a cell membrane, cytoplasm, and genetic material enclosed in a nucleus.

Question 2

B1: Name all measurements with their units and convert them to metres.

Answer 2

Kilometre(km) 1000m
Metre(m) 1m
Centimetre(cm) 0.01m
Millimetre(mm) 0.001m
Micrometre(μm) 0.000 001m
Nanometre(nm) 0.000 000 001m

Question 3

B1: What features does a plant cell consist of?

Answer 3

• Nucleus
• Cytoplasm
• Cell membrane
• Mitochondria
• Ribosomes
• Cell wall
• Chlorophyll
• Permanent vacuole

Question 4

B1: What does an animal cell consist of?

Answer 4

• Nucleus
• Cytoplasm
• Cell membrane
• Mitochondria
• Ribosomes

Question 5

B1: Name the different prts of a microscope

Answer 5

• Eyepiece lens
• Nosepiece
• Objective lens
• Coarse focus adjustment
• Stage
• Fine focus adjustment
• Diaphragm
• Clip
• Condenser
• Stage height adjustment
• Mirror/light source

Question 6

B1: Explain how some of the micrscope features work.

Think about:

• Eyepiece lens
• Objective lens
• Coarse focusing wheel
• Fine focusing wheel
• Stage
• Mirror/light source

Answer 6

The eyepiece lens: This is the bit you look through and usually has a magnification of x10.

Coarse focusing wheel: Move stage up or down to change focus.

Fine focusing wheel: Makes the focus precise.

Objective lens: The magnify of the specimen on the slide.

x4 = low power
x10 = medium power
x40 = long power

Stage: This is used to hold what is trying to be seen or viewed and to clip the slide.

Mirror/light source: Shines light through the specimen.

Question 7

B1: Name the specialised animal cells.

Answer 7

• Nerve cell
• Sperm cell
• Muscle cell
• Ciliated Epithelial cell
• Red blood cell

Question 8

B1: Name the specialised plant cells.

Answer 8

• Root hair cells
• Photosynthetic cells
• Xylem cells
• Phloem cells

Question 9

B1: What is magnification?

Answer 9

Magnification is a measure of how much bigger the image is compared to the real object.

Question 10

B1: What is resolution?

Answer 10

Resolution is the ability to distringuish between separate photo.

Question 11

B1: Which sorts of cells are ‘prokaryotic’?

Answer 11

Cells of bacteria.

Question 12

B1: Which sort of cells are ‘eukaryotic’?

Answer 12

Cells of animals and plants.

Question 13

B1: How do you convert from km to m to mm to μm to nm?

Answer 13

x1000 every conversion

Question 14

B1: How do you convert from nm to μm to mm to m to km?

Answer 14

/1000 every conversion

Question 15

B1: How do you calculate:

• Image size
• Actual size
• Magnification

Answer 15

• Actual Size x Magnification
• Image Size / Magnification
• Image Size / Actual Size

Question 16

B1: Name two substances an animal needs to take in from the environment.

Answer 16

Animals need to take in substances such as oxygen and carbohydrates(food).

Question 17

B1: Name two substances an animal needs to release into the environment.

Answer 17

Animals release substances into the air such as carbon dioxide and urea.

Question 18

B1: What is the permanent vacuole?

Answer 18

A store of water.

Question 19

B2: Why do organisms need new cells?

Answer 19

-To grow
-To replace worn out cells
-To repair damaged tissue
(Need the same genetic information to carry out the same job)

Question 20

B2: How many chromosomes do humans have which have how many pairs?

Answer 20

46 chromsomes in 23 pairs.

Question 21

B2: What is Mitosis and why is it important?

Answer 21

-Mitosis is the process where a set of chromosomes is pulled dividing the nucleus producing two identical cells.

Mitosis is important for:

• Growth
• Development in multicellular organisms
• Replacement of worn out or damaged cells

Question 22

B2: Write a summary of what happens in stage 1-3 in cell division.

Answer 22

Stage 1:

• Replication of DNA to form two copies of each chromosome and synthesis of new sub cellular structures
• Numbers of sub-cellular structures (mitochondria, ribosomes and chloroplasts) increase so it’s ready for the cell to divide

Stage 2:

-One set of chromosomes is pulled to each end of the dividing cell and the nucleus divides

Stage 3:

-This is the stage during which the cytoplasm and the cell membranes also divide to form two identical daughter cells

Question 23

B2: What is an embryonic stem cell?

Answer 23

A type of stem cell found in the embryo, capable of diving into almost any cell type. Capable of dividing into almost any cell type.

Question 24

B2: What is an adult stem cell?

Answer 24

The type of stem cell only to be found in specific locations. Can only differentiate into a limited humber of cell types.

Question 25

B2: What is differentiation?

Answer 25

As cells begin to become ‘specialised’ for specific jobs, they start to develop different features.