Standard Grade Biology – Investigating Cells Revision
DO NOT WRITE ON SHEET, ANSWER QUESTIONS IN SENTENCES IN JOTTER
1.
When a piece of onion epidermis is examined with a microscope, it can be seen to be
made up of many smaller units.
a) What are these units called?
b) What structure might be seen if a stain were used?
c) Name a stain which would make more parts visible.
2.
Which of the following structures is present in plant cells, but absent in animal cells.
A Cell Membrane
3.
B Nucleus
C Cell Wall
D Cytoplasm
Identify the structures in this diagram of a cheek cell.
A ___________________
B ___________________
C ___________________
4.
Below are 3 pairs of statements about animal or plant cells. Sort them into 2 groups.
A
B
C
D
E
F
5.
They are surrounded only by a thin cell membrane.
They have a cell wall in addition to a cell membrane.
They have a large central vacuole.
They do not have a large central vacuole.
They have chloroplasts.
They do not have chloroplasts.
The function of the nucleus is to…
a)
b)
c)
d)
…make food using light energy.
…control the entry of materials to the cell.
…keep the cell firm.
…control all the activities within the cell.
6.
The diagram below shows the effect of placing a plant cell in a concentrated sugar
solution.
a) Explain the change in appearance of the plant cell.
b) What term is used to describe the resulting
appearance of the cell?
7.
Four pieces of potato, of the same mass, were placed in 4 beakers of solution as
shown.
After 2 days, which piece of potato was
heaviest?
A
Air
8.
C
5%
Sucrose
D
20%
Sucrose
Explain this in terms of movement of
water molecules.
The optimum temperature for an enzyme is…
a)
b)
c)
d)
9.
B
Distilled
Water
…the
…the
…the
…the
lowest temperature at which it works.
highest temperature at which it works.
temperature at which it works best.
temperature at which it stops working.
Complete the following sentence.
Osmosis is the movement of ________ from a region of _______ concentration of
water, to a region of ____ concentration of _________ through a ________
__________ membrane.
10.
Choose the correct word to complete the sentence.
Oxygen diffuses from a (high/low) oxygen concentration to a (higher/lower) oxygent
concentration.
11.
Give examples of 3 substances which can enter or leave a cell by diffusion.
12.
Explain how molecules of a substance such as glucose into a cell. Use the terms “low
concentration” and “high concentration”.
13.
When red blood cells are placed in distilled water…
a)
b)
c)
d)
14.
A plant cell will not burst when placed in water because it has a…
a)
b)
c)
d)
15.
…the water will move into the cell and it will burst.
…water will neither move in or out and the cell will stay the same.
…water will move out and the cell will shrink.
…some water will enter the cell and it will swell up.
… cell membrane.
…nucleus.
…cell wall.
…vacuole.
The apparatus shown was used to investigate osmosis in potato cells.
Beaker
Cylinder of potato
The potato cylinder was weighed before, and
again 30 minutes after being placed in the
strong sucrose solution.
Strong sucrose
solution
a) Explain what would happen to the mass
of the cylinder during the 30 minutes .
b)
The change in mass was due to…
1) …sucrose moving into the cells.
2) …water moving out of the cells.
3) …sucrose moving out of the cells.
4) …water moving into the cells.
c)
Describe the appearance of the potato cells after 30 minutes in the strong sucrose
solution.
16.
Which of the substances in the following reaction is the substrate.
STARCH
Amylase
GLUCOSE
17.
Name 2 essential processes which take place inside cells, which involve enzymes.
18.
Explain the term specific when used in connection with enzymes.
19.
Enzymes are found in…
a) …some living cells
c) …all living cells
20.
b) … most living cells
d) …only dead cells.
Choose one word from each group to make the following sentence correct.
Enzymes are (carbohydrate/fat/protein) molecules present in (all/some/most) living
cells where they (speed up/slow down/stop) chemical reactions.
21.
Copy and complete the following table, which refers to the activities of 3 enzymes.
ENZYME
SUBSTRATE
Phosphorylase Glucose-1-phosphate
Amylase
Hydrogen Peroxide
22.
PRODUCT
Glucose/Maltose
Water + Oxygen
The apparatus shown was used by a pupil to investigate the action of an enzyme on
starch.
A
B
C
a) Identify enzyme X.
b) Explain what change would take place in
the contents of test tube A during the
experiment.
c) Describe a test you could use to see if
the experiment has been successful.
Starch solution
+ Enzyme X
23.
What is a control? Give an example.
Starch solution
+ Water
Enzyme X
+ Water