Download Eukaryotic Cells, (animals): biology homework revision questions

2. Animal Cells
1.
The table below refers to three organelles commonly found in eukaryotic cells. Complete the
table by writing the name of the organelle, its description or one function, as appropriate, in
each of the five boxes provided.
Name of organelle
Description
One function
Golgi apparatus
Cylindrical organelles
made up of microtubules
Involved in spindle
Organisation during cell
division in animal cells
Rod-shaped structures
with a double membrane,
the inner one folded to
form cristae
(Total 5 marks)
2.
(a)
Draw and label a diagram to show the structure of the Golgi apparatus as seen using an
electron microscope.
(3)
AS Unit 2 Development Plants and the Environment: Topic 3: The voice of the genome
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2. Animal Cells
(b)
The process of protein synthesis in cells and the secretion of proteins from the cells was
investigated using radioactively labelled amino acids.
The cells were incubated with radioactive amino acids for 30 minutes. The cells were
then removed and washed thoroughly to remove any radioactive amino acids on the cell
surfaces.
The washed cells were then incubated with non-radioactive amino acids for 120 minutes.
Every 20 minutes a sample of cells was removed and the level of radioactivity in the
rough endoplasmic reticulum and in the secretory vesicles was determined.
The graph below shows the levels of radioactivity in the rough endoplasmic reticulum
and the secretory vesicles.
80
Secretory
vesicles
70
60
50
Level of
radioactivity
/ arbitrary 40
units
30
Rough
endoplasmic
reticulum
20
10
0
0
(i)
20
40
60
80
Incubation time / min
100
120
Describe and explain the changes in the level of radioactivity in the rough
endoplasmic reticulum during the first 40 minutes of the incubation period.
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(2)
AS Unit 2 Development Plants and the Environment: Topic 3: The voice of the genome
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2. Animal Cells
(ii)
Explain the shape of the curve for the secretory vesicles between 0 and 40 minutes.
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(3)
(Total 8 marks)
3.
(a)
Identify the organelles (structures inside a cell) which fit the descriptions given in the
table below. The first one has been done for you.
Description
i
Where photosynthesis takes place and carbon dioxide
is converted into sugar
ii
Where aerobic respiration takes place
iii
Where amino acids are joined together to form
proteins
iv
Packages proteins into vesicles so that they can be
released from the cell by exocytosis
v
A large space inside a plant cell surrounded by a
tonoplast and helping to maintain cell turgidity
vi
Divides and organises a spindle in an animal cell as it
starts to undergo mitosis
Name of organelle
chloroplast
(5)
(b)
Describe the structure of pits in plant cells and explain their function.
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(2)
AS Unit 2 Development Plants and the Environment: Topic 3: The voice of the genome
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2. Animal Cells
(c)
Give two ways in which the structure of a prokaryotic cell differs from a eukaryotic cell.
1 ..................................................................................................................................
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2 ..................................................................................................................................
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(2)
(Total 9 marks)
4.
(a)
The diagram below shows a view through a typical animal cell.
The table below lists three organelles. Put a cross in the box to match each organelle with
the correct letter shown on the diagram.
Organelle
A
B
C
D
E
Rough endoplasmic reticulum
Mitochondrion
Golgi apparatus
(3)
(b)
For some time after the Golgi apparatus was identified, there was doubt as to whether it
was a new and separate organelle. Explain how the Golgi apparatus could be confused
with other organelles within a cell.
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(3)
AS Unit 2 Development Plants and the Environment: Topic 3: The voice of the genome
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2. Animal Cells
(c)
In an experiment to investigate the role of organelles in protein transport, cells were given
radioactively-labelled amino acids for a fixed period of time. The percentage of the
radioactivity found in four different organelles was then measured at different time
intervals. The table below shows the results.
Time after adding
radioactively-labelled
amino acid / min
(i)
Radioactivity present / %
Rough
endoplasmic
reticulum
Golgi
apparatus
Secretory
vesicles
Mitochondria
4
67
27
1
3
6
53
39
2
1
20
11
73
10
3
240
11
10
73
2
The data provide evidence that the Golgi apparatus is a separate organelle.
Suggest an explanation for this.
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(2)
(ii)
Explain how the data provide evidence for the sequence of events in the process of
protein transport in these cells.
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(4)
AS Unit 2 Development Plants and the Environment: Topic 3: The voice of the genome
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2. Animal Cells
(iii)
Suggest one reason for the presence of some radioactivity detected in the
mitochondria.
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(1)
(Total 13 marks)
5.
The photograph below shows a section through a mitochondrion as seen using an electron
microscope.
A
C
B
Prof. R. Bellairs/Wellcome Photo Library
(a)
Name the parts labelled A, B and C.
A ................................................................................................................................
B ................................................................................................................................
C ................................................................................................................................
(3)
(b)
Describe the role of mitochondria.
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(2)
(Total 5 marks)
AS Unit 2 Development Plants and the Environment: Topic 3: The voice of the genome
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