The mountain pygmy possum (Burramys parvus) is restricted to four regions in Australia's alpine zone. The species is listed as critically endangered with less than 2000 adults remaining. The range of the mountain pygmy possum has contracted due to a gradually warming climate. Loss and degradation of these habitats have affected local populations. The graph shows changes in the Mt Buller population following recent bushfires and the introduction of male pygmy possums from Mt Bogong. Evaluate how bushfires and the introduction of males from other locations have affected the population size and gene pool of the Mt Buller pygmy possum population. (7 marks) --- 18 WORK AREA LINES (style=lined) ---
BIOLOGY, M6 SM-Bank 25
Over time, the South African cheetah population has suffered drastic reduction due to periodic droughts, disease and hunting. Currently, only small, isolated populations of cheetahs exist in the wild.
Explain, in terms of genetic diversity, why cheetah populations are now on the verge of extinction. (3 marks)
--- 6 WORK AREA LINES (style=lined) ---
BIOLOGY, M6 SM-Bank 24
In 1950 , the myxoma virus was released into Australian pest rabbit populations to reduce their numbers. The resulting disease, myxomatosis, initially wiped out 95% of the rabbit population; however, it quickly became less effective as a population control measure.
This graph shows the frequency of myxomatosis resistance in Australia's rabbit population from 1949 to 1956.
Use evidence from the graph and the principles of natural selection to explain how myxomatosis became ineffective as a population control measure. (3 marks)
BIOLOGY, M6 2014 HSC 33d
The data compare a segment of the eye control gene in mice to the equivalent gene segment in a range of different species. The expression of these genes is necessary for eye development to begin.
Note: grey highlighted bases are the same as those in the mouse gene.
- With reference to the data in the table, explain why it is possible for different gene sequences to produce the same protein. (2 marks)
--- 5 WORK AREA LINES (style=lined) ---
- Discuss ONE strength and ONE limitation of using the data shown to determine the evolutionary relationships between these species. (4 marks)
--- 8 WORK AREA LINES (style=lined) ---
BIOLOGY, M6 2014 HSC 7 MC
Which of the following is essential in any model of natural selection?
- High reproductive rates
- Random selection of prey
- A population of predators
- Differences in the population
BIOLOGY, M6 2019 HSC 26
The map shows the percentage of adult indigenous populations able to digest lactose.
The ability to digest lactose is due to the presence of an enzyme (lactase) which can metabolise the sugar (lactose) present in milk. The gene responsible for producing lactase is usually permanently switched off at some time between the ages of 2 and 5 years. However, some people remain able to digest lactose throughout their lives.
With reference to evolution and DNA, provide possible reasons for the distribution shown in the map. (5 marks)
BIOLOGY, M6 2019 HSC 13 MC
Genetic drift is a gradual change in
- the alleles of an individual due to mutation.
- allele frequency in a population due to chance.
- the genes of a population due to natural selection.
- gene frequency in a population due to natural selection.
BIOLOGY, M6 2019 HSC 3 MC
The diagram shows the impact of birds feeding on a population of beetles over time.
Which of the following accounts for the change in the beetle population?
- Mutation
- Gene flow
- Genetic drift
- Environmental pressure
BIOLOGY, M6 2020 HSC 29
Explain how TWO processes that affect the gene pool of populations can lead to evolution. (5 marks)
BIOLOGY, M6 2020 HSC 10 MC
A farmer intends to artificially inseminate cows with semen from a bull which has been chosen based on characteristics of colour and muscle mass.
The farmer does not know that the bull is heterozygous for a rare recessive allele not previously present in the farmer's cow population.
The introduction of this recessive allele to the population of cows is an example of
- gene flow.
- genetic drift.
- natural selection.
- selective breeding.
BIOLOGY, M5 2021 HSC 26
Zebra populations are suffering from a reduction in their gene pools due to habitat destruction and increasing isolation. This has led to an increase in the number of offspring born with coat patterns different to that of their parents. An example is shown.
Explain possible reasons for the increase in these offspring. (4 marks)
--- 8 WORK AREA LINES (style=lined) ---