Name:
IB Biology Chapter Three Review Questions
1.
Many elements are necessary to form biochemicals required by living organisms. For each element below,
state the name of one molecule containing the element and state the function of the molecule.
(a) Iron:
Molecule .........................................................................
Function ..........................................................................
.........................................................................................
(2)
(b)
Phosphorus:
Molecule .........................................................................
Function ..........................................................................
.........................................................................................
(2)
(Total 4 marks)
3.
Outline the production of a dipeptide by a condensation reaction. Include the structure of a generalized
dipeptide in your answer.
(Total 5 marks)
4.
List four functions of proteins, giving an example of each.
(Total 4 marks)
6.
(a)
Define the term active site of an enzyme.
.....................................................................................................................................
.....................................................................................................................................
(1)
(b)
Outline how enzymes catalyze biochemical reactions.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(c)
Explain the effect of pH on enzyme activity.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(d)
State three functions of lipids.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(3)
(2)
(Total 8 marks)
7.
Explain the effects of temperature, pH and substrate concentration on enzyme activity.
(Total 8 marks)
8.
IB Bio
The unicellular green alga Phaeodactylum tricornutum is photosynthetic. Cell biologists genetically modified this
organism by adding a glucose transporter gene. The modified and unmodified algae were grown in a nutrient
medium under a series of different conditions and the growth rate of the cells was measured.
2014-15
Ms. Z
Name:
12
10
Unmodified algae
Key:
= light and no glucose
in the medium
Modified algae
8
Cell density /
10 7 cells cm –3 6
= light and glucose
in the medium
4
= dark and glucose
in the medium
2
0
0
2
4
6
8 0
2
Time / days
4
6
8
[Source: L A Zaslavskaia, et al., Adapted (2001) Science, 292, pages 2073–2075]
(a)
State the role of glucose in the metabolism of cells.
.....................................................................................................................................
(1)
(b)
Deduce where you would expect to find the glucose transporter protein in the modified algae cells.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(c)
Compare the effect of light on the modified and the unmodified cells.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
Commercially, unmodified algae are grown in shallow sunlit ponds or illuminated containers. The cells
only grow in the top few centimetres. However, the modified algae can grow at any depth.
(d)
Explain why the modified algae can grow at any depth whereas the unmodified algae can only grow
at the surface.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 8 marks)
9.
A certain gene codes for a polypeptide that is 120 amino acids long. Approximately how many nucleotides
long is the mRNA that codes for this polypeptide likely to be?
A.
30
B.
40
C.
360
D.
480
12.
The rate of carbon dioxide uptake by the green succulent shrub Aeonium goochiae can indicate the amount of
photosynthesis taking place in the plant. This rate was measured at 15°C and 30°C over a 24-hour period. The
units of carbon dioxide absorption are mg CO2 h–1.
The results are shown below. The centre of the graph corresponds to –2 mg CO2 h–1 & the outer ring is +2.5 mg
CO2 h–1.
(Total 1 mark)
IB Bio
2014-15
Ms. Z
Name:
2300
2200
2100 (late evening)
2000
1900
1800 (evening)
2400 (midnight)
2.5
0100
2
1.5
1
0.5
0
–0.5
–1
–1.5
–2
Key:
30ºC
15ºC
0200
0300 (early morning)
0400
0500
0600 (morning)
1700
0700
1600
0800
1500 (early afternoon)
0900 (late morning)
1400
1000
1300
1100
1200 (mid-day)
[Source: adapted from www.biologie.uni-hamburg.de/b-online/e24/9.htm]
(a)
Identify a time that carbon dioxide uptake was the same at both temperatures.
.....................................................................................................................................
(b)
State the maximum rate of carbon dioxide uptake at 15°C.
.....................................................................................................................................
(c)
Compare the rate of carbon dioxide uptake at each temperature in daylight and darkness.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(d)
Suggest why the carbon dioxide uptake may at times be negative. (1)
.....................................................................................................................................
.....................................................................................................................................
(1)
(1)
(3)
(Total 6 marks)
15.
Outline how monosaccharides are converted into polysaccharides.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
16.
Explain, with reference to its properties, the significance of water as a coolant, a means of transport & as a
habitat.
(Total 2 marks)
(Total 8 marks)
IB Bio
2014-15
Ms. Z
Name:
18.
Outline the use of carbohydrates and lipids in energy storage.
(Total 5 marks)
19.
Which is the structure of glycerol?
H H H
A.
H
C
C
C
B.
H
H
OH OH OH
C.
H
H
H
C
C
D.
H
H
OH OH
H
H
H
C
C
C
H
H
OH
H
H
C
C
H
OH
H
H
(Total 1 mark)
21.
Which of the following features are correct for hydrogen bonding?
I.
It is involved in the cohesion of water.
II.
It results in the thermal properties of water.
III. It is a bond within the water molecule.
A.
I and II only
B.
II and III only
C.
I and III only
D.
I, II and III
(Total 1 mark)
22.
What is a role of carbohydrates in animal cells?
A.
As channels for passive transport
B.
As enzymes
C.
D.
As energy storage
As components of the animal cell wall
(Total 1 mark)
Copepods are very small crustaceans and an important component of plankton in the Arctic sea ice. The
distribution of copepods, which feed on microalgae, can be related to the food and predators. The biomass
of microalgae was measured and the concentration of chlorophyll a was calculated. The graphs below show
how the concentration of chlorophyll a and copepods change with depth.
Microalgae
Copepods
Chlorophyll a / mg m–3
Relative numbers
Depth / m
Depth / m
23.
[Source: Martin Fortier, et. al., Visual predators and the diel vertical migration of copepods under Arctic sea ice during the midnight sun” (2001),
vol. 23, issue 11, pp. 1263–1278, by permission of Oxford University Press]
IB Bio
2014-15
Ms. Z
Name:
(a)
State the amount at a depth of 30 m below sea level of
(i)
chlorophyll a;
..........................................................................................................................
(ii) copepods.
..........................................................................................................................
(b)
Describe the distribution of microalgae.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(2)
(c)
Discuss factors that could affect the distribution of copepods.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(3)
(Total 7 marks)
24.
The reaction below shows the energy changes in a chemical reaction.
What would happen to the changes in energy if this reaction was controlled by an enzyme?
A.
I would increase. B. II would decrease.
C. I & IV would decrease.
D. II & III would decrease.
(Total 1 mark)
25.
IB Bio
A study was conducted on how cattle grazing affects the water content of soils. One area studied was a pasture of
alfalfa (Medicago sativa). A special probe was used to take measurements of soil water to depths of 300 mm. The
range of measurements obtained were used to calculate the total soil water content expressed in mm. Results from
part of the study during the growing season for the year 2000 are shown below.
2014-15
Ms. Z
Name:
125
Key:
grazed
un-grazed
100
Total soil water
/ mm
75
50
25
120 140 160 180 200 220 240 260 280
Day of the year
[Source: Mapfumo et al., Canadian Journal of Soil Science, (2003), 83, pp 601–614]
(a)
State the overall trend in total soil water content during the study period.
....................................................................................................................................
....................................................................................................................................
(1)
(b)
Identify the day on which the difference in total soil water content of grazed & un-grazed areas was greatest.
....................................................................................................................................
....................................................................................................................................
(1)
(c)
Discuss the effects of grazing on the total soil water content.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(4)
(Total 6 marks)
27.
IB Bio
The eastern oyster (Crassostrea virginica) is a marine mollusc that lives in estuaries. The environmental
surroundings of the eastern oyster, such as the temperature and concentration of trace elements, are
constantly changing. The trace element cadmium affects the mitochondria and prevents them from carrying
out their function efficiently. Investigators isolated mitochondria from the oysters to study how the
respiration rate changed while varying the water temperature and the cadmium ion concentration.
2014-15
Ms. Z
Name:
3.0
Key:
2.5
Respiration
rate / arbitrary
units
15 °C
25 °C
35 °C
1.5
1.0
0.5
0.0
0
1
5
10
15
20
Cadmium ion concentration / µ mol dm–3
[Source: I M Sokolova, (2004), The Journal of Experimental Biology, 207, pages 2639–2648.
With permission of the Company of Biologists Ltd.]
(a)
State the relationship between the concentration of cadmium ions and respiration rate at 35C.
.....................................................................................................................................
.....................................................................................................................................
(1)
(b)
Compare the respiration rate of the mitochondria at cadmium ion concentrations of 0mol dm–3 and
50mol dm–3.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(c)
Suggest one other environmental property of the water, apart from temperature and mineral
concentration, that may show daily changes.
.....................................................................................................................................
(2)
(1)
(d)
The investigators concluded that seasonal and global warming might make the eastern oysters more
likely to suffer from trace element poisoning.
Using the data, evaluate this hypothesis.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 7 marks)
IB Bio
2014-15
Ms. Z