HSC Biology 2020 Multiple Choice Questions

1.

In maintaining homeostasis, which of the following is a behavioural adaptation?

Sweating to cool down

Speeding up or slowing down cell metabolism

Skin going red as more blood flows to surface

Curling up in a ball to keep warm

2.

Sexual reproduction in plants involves

mitosis leading to the formation of pollen grains.

pollination caused by dispersal of seeds

cloning as it creates copies of the parent plant.

fertilisation as a result of fusion of male and female gametes

3.

The following four events occur during reproduction in a placental mammal.

1. Fertilisation
2. Implantation
3. Ovulation
4. Placental formation
In which order do these events occur?

2, 1, 3, 4

3, 2, 4, 1

2, 4, 1, 3

3, 1, 2, 4

4.

Malaria is a disease in humans caused by a single-celled Plasmodium species. It is transmitted by female mosquitoes.

Which of the following is true for malaria?

Both Plasmodium and the mosquito are pathogens

The mosquito is the vector and Plasmodium is the pathogen

The mosquito is the pathogen and Plasmodium is the vector

Both Plasmodium and the mosquito are vectors

5.

Which best describes DNA in both prokaryotic and eukaryotic cells respectively ?

Linear, Circular

Linear, Linear

Circular, Linear

Circular, Circular

6.

Citrus canker is a bacterial disease that originates in south-east Asia and affects citrus fruit.

What would be the most effective way to prevent the disease from spreading into or
across Australia?

Inspect citrus trees and fruit entering Australia in quarantine stations before transportation across Australia.

Keep citrus trees and fruit entering Australia in quarantine stations until the incubation period has passed.

Certify orchards before fruit is transported.

Monitor citrus trees and fruit continuously.

7.

Students designed and conducted an investigation to test for the presence of microbes in THREE different food samples.

They inoculated agar plates with the samples and placed them in an incubator set to 25°C.

Which row of the table represents a valid design for the investigation?

b

a

d

c

8.

A public education campaign was developed with the aim of lowering the incidence of skin cancer in the population.

The campaign was adopted Australia wide and is illustrated in the poster.

Which is the best method to measure the effectiveness of the campaign?

By comparing skin cancer incidence before and after the campaign

By counting the number of people on the beach wearing hats and sunglasses

By measuring exposure to the sun and skin cancer incidence

By surveying beachgoers, asking if they remember the campaign

9.

Quarantine is ineffective as a measure to control non-infectious diseases because they

may only be treated by genetic engineering altering cells.

may be inherited and affect the organism all their life.

cannot develop in isolation.

depend on long-term exposure to a pathogen.

10.

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

genetic drift

natural selection.

selective breeding.

gene flow

11.

The diagram shows a model of the human eye

b

d

a

c

12.

What is the purpose of cloning in agriculture?

Preserving favourable traits in the offspring

Preserving genetic variability in a population

Increasing combinations of alleles in a population

Increasing the frequency of recessive traits

13.

A type of genetic technology is shown in the diagram

What type of cloning is modelled?

Gene cloning because bacteria are used.

Whole organism cloning because identical offspring are produced.

Gene cloning because a human gene is being replicated.

Whole organism cloning because the bacteria use asexual reproduction

14.

A normal allele results in liver cells with sufficient cholesterol receptors. A different allele results in liver cells without cholesterol receptors. Individuals who are heterozygous have liver cells with insufficient cholesterol receptors.

What type of inheritance is the most likely explanation for this?

Sex-linked

Autosomal dominant

Incomplete dominance

Autosomal recessive

15.

Four antiviral drugs have been tested in a culture of human cells for their effectiveness in inhibiting infection from a new virus. The toxicity of the antivirals to human cells was also tested.

The ability of the drugs to inhibit viral entry to the cells (% inhibition) and the proportion
of the cells killed by the drugs (% toxicity) were recorded at different doses of each drug
and shown in the graphs.
From the results shown, which antiviral drug is the safest and most effective at a dose of
1 µ mol L–1?

c

d

b

a

16.

Analysis of DNA shows that adenine and guanine always make up 50% of the total amount of nitrogenous bases in DNA.

Which structural feature of DNA does this provide evidence for?

DNA is helical in structure

DNA is made up of equal amounts of nitrogenous bases.

DNA always has adenine paired with guanine

DNA is always a double-stranded molecule

17.

There are about 10 million single nucleotide polymorphisms (SNPs) found in the human genome.

Four SNPs are modelled in the diagram

The SNPs modelled do not affect the phenotype of the individuals shown.
Which is the best explanation for this?

The SNPs are present on one strand of the DNA molecule only.

The SNPs are part of DNA that is not expressed.

Only one nucleotide is different at each SNP.

AGA, CAA, TAT and CTC all code for the same amino acid.

18.

SNP databases have been used in forensic investigations. One is outlined below.

1. DNA was collected at a crime scene 30 years ago.
2. Recently the crime scene DNA was analysed at 700 000 SNP locations.
3. An SNP profile was created and uploaded to a genealogy database.
4. The SNP profile from the crime scene indicated some shared SNPs with two
individuals (who did not have SNPs in common).
5. The pedigrees were constructed for the two individuals.