THE UNIVERSITY OF THE WEST INDIES
BIOL0052 - BIOLOGY II
EXAM ASSESSMENT MAY 12TH 2020
INSTRUCTIONS: This assessment consists of FOUR (4) pages and THREE (3) questions. Each
question is worth TWENTY (20) marks. You are required to answer all THREE questions for
submission. Please note that diagrams obtained from websites are not acceptable, any diagram requested
must be drawn by the student.
Q.1
Answer ALL parts:
Consider the scenario given below and answer the questions that follow:
A particular beetle species possesses three variants in terms of shell phenotype; solid, spotted and
striped. In a given population, the solid-coloured shell is the average expression and the spotted and
striped beetles lie on the extremes as shown below:
Figure 1: Frequency of shell phenotype in the beetle population
Researchers monitoring this population over time have realized that the solid beetles are decreasing in
numbers, whilst the striped and spotted beetles are starting to occupy separate niches. The spotted
beetles live on the trunks of trees, whilst the striped beetles live on the forest floor. The two types of
beetles do not mate with one another.
(a) Discuss the following in terms of this beetle population:
i. Natural selection
ii. Speciation.
(10 marks)
(b) Which factor(s) could have been possible selection pressures against the solid beetle?
(c)
(2marks)
With the aid of a diagram illustrate the type of natural selection which is being demonstrated in the
scenario.
(4 marks)
(PLEASE TURN OVER)
Page 2
(d) How does the type of speciation depicted in this scenario differ from allopatric speciation?
(4 marks)
Q.2
Answer ALL parts:
The scheme shown below in Figure 2, outlines the fate of glucose during cellular respiration:
Glucose
(I)
Pyruvate
(II)
Acetyl CoA
(V)
Lactic acid
(VI)
Acetaldehyde
(VII)
Ethanol
(III)
Oxidative
phosphorylation
(IV)
Figure 2: Schematic representation of the fate of glucose during respiration
(a) Name the process identified as (III) in the scheme.
(1 mark)
(b) Diagram the steps involved in the process stated in (a)
(10 marks)
(c) Redraw and complete the table given below concerning oxidative phosphorylation:
(6 marks)
Table 1: Oxidative phosphorylation in the mitochondrion
Role in oxidative phosphorylation
Molecule or structure
Hydrogen and electron donors
Final electron acceptor
Proton reservoir site
Site of ATP synthesis
(PLEASE TURN OVER)
Page 3
(d) Identify process (II) and explain why process (II) is important in order for process (III) to occur. (3 marks)
Q.3
Answer ALL parts:
(a) The images shown below illustrate the appearance of the loblolly pine (Figure 3) and the prickly pear
cactus (Figure 4). The loblolly pine is found in lowland, swampy areas whilst the prickly pear cactus is
found in arid environments. State two adaptations of the prickly pear cactus, as shown in the
figure, that make it suited for existing in an arid environment.
(2 marks)
Figure 3: Loblolly pine
Figure 4: Prickly pear cactus
(b) Figure 5 shows the masses of water transpired and absorbed by the loblolly pine and the prickly
pear cactus over a 24 hour period.
(PLEASE TURN OVER)
Page 4
i.
The continuous movement of water through the plant is essential for facilitating the
process of photosynthesis in the leaves. Explain how this continuous column of water is
maintained.
(10 marks)
ii.
Describe and explain the patterns of transpiration and water absorption in the loblolly
pine.
(5 marks)
iii.
Suggest why the pattern of transpiration for the prickly pear is not the same as that of
the loblolly pine.
(3 marks)
- END OF ASSESSMENT -