SCSA Human Biology Response to infection
5 sample questions with marking guides and sample answers · Avg. score: 100%
Antibiotics are ineffective against viruses because viruses
keep changing their external protein coat.
are able to disguise themselves in the host cell membrane.
are not living cells and thus do not metabolise.
can change antibiotics into useful food substances.
An example of natural active immunity is a
breastfed baby who does not catch a cold that they are exposed to.
hospital worker who is vaccinated against the flu.
person bitten by a snake who is given anti-venom antibodies.
child who contracts chicken pox and does not get the disease again.
During the 2024 Olympic Games in Paris, the cleanliness of the River Seine was of concern. High levels of the bacteria Escherichia coli (E. coli) were detected in the river, presenting potential health risks for the athletes competing in the triathlon and open-water swimming events. Several athletes were treated for E. coli infections.
Contrast three features of bacteria and viruses.
In addition to severe nausea, the unwell swimmers started feeling cold, shivering uncontrollably and were asking for blankets, despite the outside temperatures being warm.
Name and outline the physiological responses the swimmers' bodies were having to the infection.
After swimming in the River Seine, Australian athletes were prescribed antibiotics to prevent an E. coli infection.
Antibiotics can be classified into two groups based on their mode of action. Name these two groups and outline how they fight bacterial infections.
Mumps is a disease caused by a RNA virus. Patients with mumps experience a variety of symptoms, which could include painful and swollen glands in the neck. Mumps is transmitted via droplets.
Identify and describe four external defence mechanisms found in the human body that could help prevent the entry of the mumps pathogen.
Immunisation against mumps can be achieved with vaccination. Distinguish between the terms ‘immunisation’ and ‘vaccination’. Explain how vaccines provide immunity to pathogens and outline four different types of vaccines available.
Mary Mallon was an asymptomatic carrier of the Salmonella typhi bacteria who caused several outbreaks of typhoid fever in the early 1900s. She became known as 'Typhoid Mary' and the story is a famous example of disease transmission and the need for public health measures.
Mary worked as a cook in New York homes, with many people developing typhoid fever while she was employed. She was never sick with the disease herself but was tested and identified as an asymptomatic carrier of the disease. Individuals become infected with typhoid fever from the ingestion of the Salmonella typhi bacteria. It is believed Mary was responsible for as many as 122 cases of the disease.
Bacteria can be treated with either antibiotics or a vaccine.
Given the evidence outlined above, identify the most likely mode of transmission for the typhoid fever pathogen.
Identify the location of the most important external body defence mechanism in preventing the spread of Salmonella typhi and outline two ways in which it prevents pathogens entering the internal environment.
List two ways in which a fever can help the body fight an invading pathogen.
Explain the physiological mechanisms that produce a fever.
Describe the key difference between when a person should be treated with antibiotics and when they should be treated with a vaccine.
Present two separate arguments for whether antibiotics and/or a vaccine is the best method of treating a population exposed to, or at risk of, exposure to a disease such as typhoid fever.