Stage 2 Biology Test: Evolution

SACE ID:

1. Which one of the following statements is evidence that prokaryotic cells existed before eukaryotic cells? KA1

• J. Prokaryotic organisms are single-celled and less complex than eukaryotic cells.
• K. The oldest-known prokaryotic fossils are at least 3.5 billion years old whereas the oldest known eukaryotic fossils are at least 1 .5 billion years old.
• L. Prokaryotic organisms are able to live and thrive in hostile environments such as hydrothermal vents, swamps, and wetlands.
• M. The cells of prokaryotic organisms do not contain membrane-bound organelles where as the cells of eukaryotic organisms do contain membrane-bound organelles.

2. Refer to the following table, which shows amino acid sequences from a segment of a viral protein that is found in a number of different viruses. These viruses were isolated from patients suffering from either the common cold (caused by a rhinovirus) or influenza. Each letter represents a single amino acid. IA3

• J. The rhinoviruses are more closely related to each other than the influenza viruses are to each other.
• K. Influenza virus A is more closely related to influenza virus B than influenza virus B is to influenza virus C.
• L. The influenza viruses are less closely related to each other than they are to the rhinoviruses.
• M. Rhinovirus 2 is more closely related to rhinovirus 3 than it is to rhinovirus 1.

3. Refer to the phylogenetic tree to answer the question that follows: KA2

• J. The dog and the wolf probably share more in common with their DNA than other species.
• K. All of the organisms have shared a common ancestor from the order Carnivora.
• L. The leopard has not evolved over 60 million years.
• M. The leopard and the otter have had separate gene pools for over 60 million years.

4. DNA-DNA hybridisation is a technique used to determine the similarity of DNA from different species. In this technique: •DNA is extracted from different species and cut into pieces using special enzymes; •the DNA is heated to separate the double strands into single strands; •single strands of DNA from different species are mixed together and cooled so that double strands of hybrid DNA form. Hybrid DNA consists of one strand from each of two different species. Heat is then used to test how well the strands in the hybrid DNA have joined. The DNA nucleotides must match more closely in hybrid DNA strands that separate at a higher temperature than in hybrid DNA strands that separate at a lower temperature. The following table shows the temperature (oC) needed to separate the hybrid DNA strands of four different species, Q, R, S, and T.

• J Q is more closely related to S than it is to R or T.
• K S is more closely related to R than Q is to T.
• L Q is more closely related to R than S is to T.
• M S is more closely related to T than it is to R or Q.

5. When the Pacific island of Pingelap was devastated by a storm in 1775, only about 20 people survived. One of the survivors was totally colour-blind. The survivors remained on the isolated island and re-established the population. Less than 0.01% of the world’s population is totally colour-blind. In 2015, it was estimated that 10% of the Pingelap population was totally colour-blind. The high frequency of total colour-blindness in the Pingelap population is likely to be due to KA2

• J. adaptive radiation.
• K. mutation.
• L. genetic drift.
• M. allopatric speciation.

6. Refer to the following diagram, which shows an organelle found in a eukaryotic cell:

• J.
• K.
• L.
• M.

7. Which of the following combinations describes a reproductive isolating mechanism, classifies the type of mechanism and indicates when it occurs. KA2

• J.
• K.
• L.
• M.

8. Which one of the following best represents the series of events that could lead to the formation of two separate species from one original common ancestor? KA1

• J Variation, Geographic Isolation, Natural Selection, Speciation.
• K Natural Selection, Reproductive Isolation, Variation, Speciation.
• L Geographic Isolation, Speciation, Variation, Reproductive Isolation.
• M Variation, Reproductive Isolation, Speciation, Natural Selection

9. Copies of a segment of DNA from species X were hybridised with copies of the homologous segment of DNA from species A. The hybridised DNA segments were heated, and the temperature at which complete separation occurred (separation temperature) was recorded. In order to determine evolutionary relationships, this process was repeated three times using DNA from species B, C, and D in place of DNA from species A. The results are shown in the table below IAE3

• J. Species A and species X have the least percentage difference in their DNA.
• K. Species A and species B together have the same percentage difference in DNA from species X as has species C.
• L. Species C is more closely related to species D than it is to species X.
• M. Species D and species X have the least percentage difference in their DNA.