MEMORANDUM
BASIC BIOLOGY
BLG1501
OCTOBER/NOVEMBER EXAMINATION 2011
Marks:
100
Duration: 2 hours
QUESTION 1
1.1 B
1.2 B
1.3 C
1.4 C
1.5 B
1.6 D
1.7 A
1.8 B
1.9 C
1.10 D
10 x 2 =[20]
QUESTION 2
2.1 Boundaries (edges) between ecosystems and along prominent features within ecosystems
have unique sets of physical conditions and communities of species.
Edges become more extensive as habitat fragmentation increases, and edge-adapted species
may become more dominant. Movement corridors may promote dispersal and help sustain
populations or they may promote harmful conditions such as disease. (6)
2.2
Alcohol fermentation Lactic acid fermentation
Pyruvate is converted to ethanol in two steps Pyruvate is directly reduced by NADH to
form lactate as an end product
Carbon dioxide is released from the pyruvate No release of carbon dioxide
and forms acetaldehyde
Acetaldehyde is reduced by NADH to
ethanol
(6)
2.3
Fermentation Cellular respiration
Final electron acceptor is an organic The final electron acceptor is oxygen
molecule pyruvate (lactic acid fermentation
or acetaldehyde (alcohol fermentation)
Harvest less energy Harvest more energy
Yields 2 ATPs Yields 38 ATPs
Anaerobic conditions Aerobic condition
(10)
2.4 4 The three domains of life are
Bacteria
Archaea
Eukarya
(3) [25]
BASIC BIOLOGY
BLG1501
OCTOBER/NOVEMBER EXAMINATION 2011
Marks:
100
Duration: 2 hours
QUESTION 1
1.1 B
1.2 B
1.3 C
1.4 C
1.5 B
1.6 D
1.7 A
1.8 B
1.9 C
1.10 D
10 x 2 =[20]
QUESTION 2
2.1 Boundaries (edges) between ecosystems and along prominent features within ecosystems
have unique sets of physical conditions and communities of species.
Edges become more extensive as habitat fragmentation increases, and edge-adapted species
may become more dominant. Movement corridors may promote dispersal and help sustain
populations or they may promote harmful conditions such as disease. (6)
2.2
Alcohol fermentation Lactic acid fermentation
Pyruvate is converted to ethanol in two steps Pyruvate is directly reduced by NADH to
form lactate as an end product
Carbon dioxide is released from the pyruvate No release of carbon dioxide
and forms acetaldehyde
Acetaldehyde is reduced by NADH to
ethanol
(6)
2.3
Fermentation Cellular respiration
Final electron acceptor is an organic The final electron acceptor is oxygen
molecule pyruvate (lactic acid fermentation
or acetaldehyde (alcohol fermentation)
Harvest less energy Harvest more energy
Yields 2 ATPs Yields 38 ATPs
Anaerobic conditions Aerobic condition
(10)
2.4 4 The three domains of life are
Bacteria
Archaea
Eukarya
(3) [25]
