Cell Biology

Question 1

Cell membrane

Is it in a plant or animal cell? What is its function?

Answer 1

It is found in both plant and animal cells.
It controls what comes in and out.
Outermost layer in animal cell and right inside the cell wall in plant cell

Question 2

Cell sap

Is it in a plant or animal cell? What is its function?

Answer 2

It is found in plant cells only.
It is water and a store of nutrients.
Found in vacuole

Question 3

Cellulose wall

Is it in a plant or animal cell? What is its function?

Answer 3

It is found in plant cells only.
It is made of cellulose which strengthens the cell.
Outermost layer

Question 4

Chloroplast

Is it in a plant or animal cell? What is its function?

Answer 4

It is found in plant cells only.
It contains chlorophyll which is needed for photosynthesis.
Looks like pod full of bone shaped things in diagram.

Question 5

Cytoplasm

Is it in a plant or animal cell? What is its function?

Answer 5

It is found in both plant and animal cells
It dictates the structure and is where chemical reactions occur.
Main area of cell

Question 6

Mitochondria

Is it in a plant or animal cell? What is its function?

Answer 6

It is found in both plant and animal cells.
It converts glucose into energy via respiration.
Same shape as chloroplast in diagram but has stripy inside

Question 7

Nucleus

Is it in a plant or animal cell? What is its function?

Answer 7

It is found in both animal and plant cells.
It controls the cell and stores information.
Circle roughly in the centre in diagram.

Question 8

Ribosomes

Is it in a plant or animal cell? What is its function?

Answer 8

It is found in both animal and plant cells.
It makes proteins.
Looks like dots on a diagram

Question 9

Vacuole (permanent)

Is it in a plant or animal cell? What is its function?

Answer 9

It is only found in plant cells.
It contains sap and helps support the cell.
Looks like clear blob in cytoplasm

Question 10

Drawing microscope diagrams - principles

Answer 10

Sharp pencil
Clear continuous lines
No shading
Accuracy - guidelines
Large enough - roughly A5
Include a title
Include a scale - magnification eg 100x
Label all relevant structures
No arrowheads
Label lines don’t cross each other
Labels written horizontally

Question 11

Which structures are visible using an electron microscope that are not visible using a light microscope?

Answer 11

Sub-cellular structures

Question 12

What does resolution mean?

Answer 12

Ability of a microscope to see two adjacent points as separate from one another

Question 13

What does magnification mean?

Answer 13

Magnification is how many times bigger the image appears down the microscope.

Question 14

What is the formula for image size, actual size and magnification?

Answer 14

A x M = I

Question 15

What are proteins made from?

Answer 15

Amino acid

Question 16

Units of measurement

Answer 16

Centimetres (cm), millimetre (mm), micrometer (μm), nanometre (nm)

Question 17

cm to mm

Answer 17

x10

Question 18

mm to μm

Answer 18

x1000

Question 19

μm to nm

Answer 19

x1000

Question 20

nm to μm

Answer 20

/1000

Question 21

μm to mm

Answer 21

/1000

Question 22

mm to cm

Answer 22

/10

Question 23

How to calculate overall magnification:

Answer 23

Eyepiece magnification x objective magnification

Question 24

Red blood cell

Answer 24

Biconcave disc shape
Large surface area
No nucleus
Contain haemoglobin

Question 25

Muscle cell

Answer 25

Elongated
Many mitochondria
Can contract

Question 26

Fat cell

Answer 26

Contain an energy store
Can increase in size
Very little cytoplasm

Question 27

Cone cell

Answer 27

Outer segment filled with visual pigment
Many mitochondria
One end links up with a nerve cell

Question 28

Egg cell

Answer 28

Can be enormous (especially in birds)

Half the number of chromosomes in the nucleus

Question 29

Phloem

Answer 29

Elongated tubular shape with thin walled sieve tubes
Sieve tubes have pores at each end in the cross walls and microtubules that extend between sieve elements allowing longitudinal flow of material

Question 30

Nerve cell

Answer 30

Long and thin
Form connections with neurones and muscle cells
Carry electrical impulses

Question 31

Sperm cell

Answer 31

Half the normal number of chromosomes in the nucleus
Acrosome contains digestive enzyme
Many mitochondria
Long tail

Question 32

Palisade cell

Answer 32

Regular shape to pack tightly together
Many chloroplasts
Chloroplasts contain chlorophyll

Question 33

Guard cells

Answer 33

Banana’ shape
Found in pairs
Contain chloroplasts
Ability to change shape

Question 34

Root hair cell

Answer 34

Form long hollow tubes
Walls contain lignin, a strengthening material
Dead- no cell contents

Question 35

Xylem

Answer 35

Thin cell wall
Large surface area
Many mitochondria for respiration

Question 36

What are stem cells?

Answer 36

Stem cells are unspecialised cells that are capable of producing many different types of cell through the process of cell differentiation. They differentiate into all the types of cells in the body. Their ability to do this is called pluripotent.

Question 37

What are the 2 types of animal stem cells?

Answer 37

Embryonic stem cells

Adult stem cells

Question 38

Embryonic stem cells

Answer 38

These cells make up the embryo following fertilisation. These cells are capable of dividing and differentiating to become every type of cell the organism needs

Question 39

Adult stem cells

Answer 39

Are the only source of stem cells once the foetus is mature. They retain some ability to divide and differentiate but these cells only grow in certain parts of the body (Eg bone marrow) and can only turn into a few types of blood cell.