Section A: 15 marks
Section B: 29 marks
Test No. 4
Total: 44 marks
Suggested time: 55 minutes
Question 5
SECTION A - Multiple-choice questions
Instructions to students
Use a PENCIL for ALL entries. For each question, shade the box
which indicates your answer. All answers must be completed like
THIS example:
What is the name of the process in which each peptide
is actually assembled, and where does this process take
place?
Marks will NOT be deducted for incorrect answers. NO MARK
will be given if more than ONE answer is completed for any
question. If you make a mistake, ERASE this incorrect answer DO NOT cross it out. A correct answer scores 1, an incorrect
answer scores 0.
peptides are assembled on ribosomes; the process is
A
B
C
D
C. translation, on ribosomes.
called translation.
Question 6
USE PENCIL ONLY
ONE ANSWER PER LINE
Chloroplasts are found in:
1
A
B
C
D
6
A
B
C
D
2
A
B
C
D
7
A
B
C
D
Prokaryotes do not have membrane bound
3
A
B
C
D
8
A
B
C
D
organelles. Leaf cells also include vascular tissue etc
4
A
B
C
D
9
A
B
C
D
which do not contain chloroplasts.
5
A
B
C
D
10
A
B
C
D
D. some leaf cells.
Question 7
What molecule is produced in the light reactions of
photosynthesis and used in the light-independent
reactions of photosynthesis?
Question 1
Proteins are secreted from a cell in structures known as:
B. ATP
B. vesicles.
ATP and O2 are produced in the light reactions. O2 is
vesicles merge with the cell membrane and spill
released to the atmosphere and takes no further
contents into the intercellular fluid.
part in photosynthesis.
Question 8
Question 2
The light-independent reactions of photosynthesis do
not normally take place at night because:
Many proteins are unable to be secreted directly across
the plasma membrane because:
B. they rely on the products of the lightdependent reactions.
ATP and NADPH are required for the light-
C. they are large polar molecules.
Proteins are large molecules, which may have a
independent reactions. These are produced in the
charge on some portions of the molecule and thus
light-dependent reactions.
are polar. Such molecules do not readily cross the
Question 9
phospholipid membrane.
Radioactive oxygen (18O) is introduced into the
environment of an experimental plant. After a short
period of exposure to sunlight, the radioactive oxygen
is detected in sugars in the leaf cells of the plant. The
18
O was most likely introduced to the plant’s
environment in the molecule:
Question 3
A basic difference between animal and plant cells is that
animal cells do not have:
A. CO2
C. a cell wall.
Water molecules are split in the light-dependent
You should know this.
reaction, the oxygen is released and takes no further
part in photosynthesis. The oxygen in glucose
comes from the oxygen in CO2.
Question 4
Question 10
What is the best description of transcription ?
The electron transport stage of cellular respiration
involves the production of the waste product:
B. The process in which DNA is copied into RNA.
Transcription produces a copy of the DNA as
C. water.
messenger RNA.
Oxygen is consumed; CO2 is produced in the Krebs
(Citric acid) cycle. Lactic acid is produced
anaerobically and does not involve electron
transport.
15
Test 4
Question 15
USE PENCIL ONLY
ONE ANSWER PER LINE
11
A
B
C
D
14
A
B
C
D
12
A
B
C
D
15
A
B
C
D
13
A
B
C
D
Endergonic (anabolic) reactions in cells include:
A. the production of glucose in photosynthesis.
Endergonic reactions require an input of energy and
involve the production of complex organic molecules
from relatively simpler molecules. All 3 other
Question 11
alternatives involve the exergonic breakdown of
Glycolysis occurs:
complex molecules to simpler molecules.
A. in the cytosol of cells.
Glycolysis occurs in the cytosol. Later stages of
respiration occur in the mitochondria never in
chloroplasts.
Question 12
The products of the process of glycolysis are:
B. pyruvate and ATP.
Glucose → 2 pyruvate + 2 ATP
Question 13
Sliders are small fresh-water turtles common in North
America. They are able to remain under water for days
at a time, not breathing at all. During a long period of
being submerged you would expect the slider to:
B. have high concentrations of lactic acid in its
muscle cells.
When deprived of oxygen animal cells can produce
energy through anaerobic respiration. Lactic acid is
a product of this reaction.
C6H12O6 → 2 lactic acid + 2 ATP.
The following photograph is of a cell organelle.
Question 14
This organelle is:
A. called a mitochondrion and is the site of
aerobic respiration.
Note the folded internal membranes and the overall
shape of the organelle.
16
Test 4
SECTION B - Short-answer questions: Instructions to students
Answer this section in pen. Answer all questions in the spaces provided.
The same plant was kept in the dark for the period of
time X – Y.
Question 1
The following diagram shows a section of a chloroplast.
e. i. On the axes above, show what will happen to the
partial pressure of O2 in the time period X – Y.
B
ii. Explain why you have drawn the graph the way
you have.
In the absence of light, the plant will stop the
light-dependent reactions of photosynthesis
and hence stop producing oxygen. It will
continue to respire aerobically. This process
requires and consumes oxygen, leading to a
decrease in the partial pressure of oxygen in
the surrounding air.
1 + 2 = 3 marks
Total 9 marks
A
a. Name the regions labeled:
i. A
Granum or thykaloids
ii. B
Stroma
1 + 1 = 2marks
b. Chloroplasts are the site of photosynthesis. Write a
balanced equation for photosynthesis.
6CO2 + 12H2O
chlorophyll
light energy
C6H12O6 + 6O2 + 6H2O
1 mark
Question 2
c. Photosynthesis involves two sets of reactions in the
chloroplasts, the light-dependent and lightindependent reactions. What are the products of
these reactions?
i. Light-dependent reactions.
O2, ATP, NADPH
ii. Light-independent reactions.
C6H12O6 , H2O
1 + 1 = 2marks
A student who was asked to present his understanding
of energy transfer in plant cells produced the following
diagram.
ENERGY
The graph below shows the change in the partial
pressure (concentration) of oxygen in the air
surrounding an experimental plant kept in bright light.
H2O
OXYGEN
H2O
PROCESS 1
GLUCOSE
PROCESS 2
Stored as starch
or converted to
other organic
molecules.
CO2
Partial pressure of O2
CO2
ENERGY
ADP + Pi
ATP
a. i. What process is represented as PROCESS 1?
Photosynthesis
ii. What is the source of energy for this process?
Light, usually sunlight.
1 + 1 = 2 marks
X
Y
b. i. What process is represented as PROCESS 2?
Aerobic cellular respiration
time
ii. In what organelle would this process occur?
Mitochondria
1 + 1 = 2 marks
d. Explain why the partial pressure of O2 has increased.
O2 is a product of the light dependent reactions
of photosynthesis and is released into the
atmosphere. The rate of photosynthesis in
bright light is greater than the rate of
respiration, in which O2 is used, and so O2
accumulates in the atmosphere around the
plant.
1 mark
17
Test 4
The student’s diagram does not present a complete
picture of matter and energy transfers within a plant
cell.
The parietal cells of the stomach are able to use this
mechanism to pump and concentrate hydrochloric acid
in the stomach.
c. Improve on the diagram by showing:
i. the pathway of oxygen
ii. the fate of the energy produced in PROCESS 2
iii. two other uses of the glucose produced in
PROCESS 1.
1 + 1 + 1 = 3 marks
Total 7 marks
d. i. What organelle is likely to be present in increased
numbers in parietal cells to facilitate this process?
Mitochondria
ii. Explain your answer to d. i.
There would be many mitochondria present
in parietal cells to provide energy for this
process.
1 + 1 = 2 marks
Total 5 marks
Question 3
A scientist separated pieces of plasma membrane from
an animal cell and put them in equipment so that the
membrane separated two reservoirs, one of distilled
water (A) and the other acid (B). When she added a
dilute solution of acid to one side (side A) of the
membrane, the acidity of the solution on the other side
(side B) did not change. (Experiment 1)
Question 4
ATP has been called the energy currency of the cell. It
is a portable molecule able to move to the parts of the
cell where energy is required.
a. Outline the process by which ATP provides energy
for cellular processes.
ATP breaks down to form ADP plus an
inorganic phosphate. Energy is released in this
reaction.
1 mark
membrane
material
Acid (H+)
B
pH 6.7
A
b. Name two cellular functions which use the energy
provided by ATP.
Two of: active uptake/transport, endocytosis,
exocytosis, synthesis of macromolecules,
movement, signal transduction.
2 marks
She then ground up a culture of animal cells and added
this cell extract to side A. The pH of the solution in side
B then dropped. (Experiment 2)
Eukaryotic cells generally manufacture ATP by aerobic
cellular respiration, but are able to produce ATP by the
anaerobic breakdown of glucose molecules. This
reaction is less efficient than aerobic respiration.
membrane
material
Acid (H+)
+ cell extract.
A
c. i. Under what conditions will animal cells produce
ATP by anaerobic breakdown of glucose?
When the requirement for ATP is greater than
the ability of the cell to manufacture it in
aerobic respiration due to a lack of oxygen.
This may occur in strenuous exercise or when
the animal is deprived of oxygen e.g. a
prolonged period under water.
B
pH 6.3
a. Why did the acidity of solution B in experiment 1 not
change?
There was no movement of H ions into solution
B.
1 mark
ii. What are the products of anaerobic breakdown of
glucose in animal cells.
Lactic acid and ATP.
b. Explain what was present in the cell extract that
enabled the passage of H+ ions across the
membrane.
The presence of mitochondria which provided
energy for transfer of the H ions.
1 mark
iii. In what ways is this reaction less efficient than
aerobic respiration.
It produces only two molecules of ATP per
glucose molecule whereas aerobic respiration
produces 36-38 molecules of ATP. It leaves a
relatively energy rich product (lactic acid)
compared with the simple molecules CO2 and
H2O produced in aerobic respiration.
2 + 1 + 2 = 5 marks
Total 8 marks
c. What name is given to the type of transport that
occurs in experiment 2?
Active transport
1 mark
18
Test 4