Biology

The diagram below shows a point mutation occurring on a strand of DNA.
What is the most likely possible outcome of this point mutation on the phenotype of the individual?
(A) Change to phenotype as the mutation occurs on non-coding DNA.
(B) No change to phenotype as the mutation occurs on non-coding DNA.
(C) Change to phenotype as all mutations affect the phenotype, regardless of where they occur.
(D) No change to phenotype as point mutations do not affect the phenotype of the individual.

Certain diseases can be caused by the ingestion of food contaminated with a pathogen that is a misfolded protein. This type of pathogen is a:
(A) prion
(B) plasmid
(C) parasite
(D) virus

Babies born in Australia are tested after birth for phenylketonuria (PKU). Individuals with PKU cannot metabolise the amino acid phenylalanine but can remain healthy if they avoid eating high-protein foods. PKU is a(n):
(A) nutritional disease
(B) environmental disease
(C) infectious disease
(D) genetic disease

Scientists are investigating the mitochondrial genomes of different Aboriginal Australian populations. A purpose of these investigations is to reveal the pathways of migration of Aboriginal Australians who arrived from Sahul. Mitochondrial DNA can be used for this purpose because it
(A) contains genes that code for enzymes.
(B) is always the same in specific populations.
(C) is conserved through the maternal lineage.
(D) is more structurally stable than nuclear DNA

Which epigenic mechanism can repress gene expression?
(A) Methylation of DNA
(B) Acetylation of histones
(C) Transcription of non-coding RNAs
(D) Chromosomal recombination

In the technique of genetic profiling, each DNA profile represents several loci (gene positions) on a pair of homologous chromosomes. DNA profiles for three animals of the same species are shown below.

At how many loci is Animal 2 homozygous?
(A) 1
(B) 2
(C) 3
(D) 4

In the technique of genetic profiling, each DNA profile represents several loci (gene positions) on a pair of homologous chromosomes. DNA profiles for three animals of the same species are shown below.

If Animal 1 mated with Animal 3 and produced a single offspring, the offspring
(A) Must be homozygous at locus A
(B) May be homozygous at locus D
(C) Could be either homozygous or heterozygous at locus C
(D) Must be heterozygous at locus E

Birds that live in cold environments have a counter-current heat exchange system in their legs, which is shown in the diagram below. The temperature of the blood is lowest at position
(A) A
(B) B
(C) C
(D) D

The diagram below shows a pedigree of a family carrying the sex-linked allele for red-green colour blindness.

From which member of his family did E inherit the allele for colour-blindness?
(A) A
(B) B
(C) C
(D) D

A plant pathologist observed brown spots developing on the leaves of a lemon tree and wanted to determine the cause of the disease. The pathologist suspected the tree was suffering from a bacterial disease, caused by infection with Xanthomonas citri.
Outline TWO plant adaptations for defence against pathogens.

A plant pathologist observed brown spots developing on the leaves of a lemon tree and wanted to determine the cause of the disease. The pathologist suspected the tree was suffering from a bacterial disease, caused by infection with Xanthomonas citri.
Describe the steps a pathologist could use to test the hypothesis that the suspected bacterium is the cause of the disease.

The cheetah (Acinonyx jubatus) is a vulnerable species of large cat, known for being the fastest land animal. Since the 19th century, it is estimated that the cheetah population has declined from 100,000 to approximately 8,000 cheetahs. The cheetah faces extinction due to climate change, hunting by humans and habitat destruction. They also have a low rate of reproductive success.

Explain how information gained through DNA profiling of cheetah populations can help direct efforts to conserve them.

The cheetah (Acinonyx jubatus) is a vulnerable species of large cat, known for being the fastest land animal. Since the 19th century, it is estimated that the cheetah population has declined from 100,000 to approximately 8,000 cheetahs. The cheetah faces extinction due to climate change, hunting by humans and habitat destruction. They also have a low rate of reproductive success.
Describe how DNA profiling can be used to show genetic diversity within a population.

Compare the processes of DNA replication and Polymerase chain reaction (PCR). Marks

Influenza is an infectious respiratory disease. In humans, it can be caused by the influenza A or influenza B viruses Natural killer cells and cytotoxic T cells both play an important part in the human immune response to the virus causing influenza. Compare the roles played by each of these two types of cells in the immune response to the influenza virus.

The following graph, which shows the distance between the sister chromatids of a replicated chromosome during a mitotic cell division: Draw diagrams to show the arrangement of the chromosomes at 10 minutes, 15minutes and at 20 minutes in a diploid cell containing four chromosomes. Pattern at 10min. Pattern at 15 min Pattern at 20min

E-cigarette operate by vaporising a nicotine containing liquid into an aerosol, which is then inhaled by the user. Since their first introduction to broad global markets in 2007, use has become increasingly common, particularly among youth. They were initially introduced as an alternative to traditional tobacco smoking, with the idea that it could potentially be less harmful due to the absence of tar and combustion products found in tobacco smoke. However, concerns have arisen about the safety and health risks associated with vaping.
Describe and justify an epidemiological study that could be carried out to investigate whether vaping using e-cigarettes causes lung disease.

Foot-and-mouth disease, a contagious viral disease for cattle, sheep, goats and pigs, resurfaced in Indonesia in May 2022 after the country had been declared free of it for over 30 years. What makes FMD virus so remarkable is its environmental resistance. It can persist on many inanimate objects, such as equipment used with livestock, people’s clothing and shoes, on the tyres of vehicles and in livestock transport. It can also persist in livestock feed and livestock products, such as meat and hides. There is no cure for FMD.
Outline the possible effects of FMD being spread to Australia.

Foot-and-mouth disease, a contagious viral disease for cattle, sheep, goats and pigs, resurfaced in Indonesia in May 2022 after the country had been declared free of it for over 30 years. What makes FMD virus so remarkable is its environmental resistance. It can persist on many inanimate objects, such as equipment used with livestock, people’s clothing and shoes, on the tyres of vehicles and in livestock transport. It can also persist in livestock feed and livestock products, such as meat and hides. There is no cure for FMD. Outline a strategy that could prevent the spread of FMD to Australia.

Use an example to outline the role of the nervous system in maintaining homeostasis.

Describe TWO mechanisms in plants that allow water balance to be maintained

The graph below shows how the levels of three hormones change during pregnancy.
How does the source of progesterone change as pregnancy progresses?

The graph below shows how the levels of three hormones change during pregnancy.
Outline ONE role of oestrogen during pregnancy.