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Helicobacter pylori is a bacterium - VCE - SSCE Biology - Question 2 - 2003 - Paper 1
Question 2
Helicobacter pylori is a bacterium. a. i. Cells can be classified as prokaryotic or eukaryotic. To which group do bacterial cells belong? ii. Name one feature w... show full transcript
Worked Solution & Example Answer:Helicobacter pylori is a bacterium - VCE - SSCE Biology - Question 2 - 2003 - Paper 1
Step 1
Step 2
ii. Name one feature which distinguishes prokaryotic organisms from eukaryotic organisms.
Answer
One key feature that distinguishes prokaryotic organisms from eukaryotic organisms is that prokaryotic organisms lack a membrane-bound nucleus, whereas eukaryotic cells have a distinct nucleus that encapsulates their genetic material.
Step 3
Explain what makes the environment of the stomach unsuitable for the survival of some bacteria?
Answer
The environment of the stomach is highly acidic due to gastric acid, which can have a pH as low as 1.5 to 3.5. This low pH is harmful to many bacteria that are not acid-resistant, leading to their inability to survive in such an environment. Additionally, the constant presence of digestive enzymes further contributes to the hostile conditions for several bacterial species.
Step 4
Suggest a feature of Helicobacter pylori that could assist the bacteria’s survival in the stomach.
Answer
Helicobacter pylori has developed a unique ability to survive in the acidic environment of the stomach by producing an enzyme called urease. This enzyme neutralizes the gastric acid around the bacterium, creating a more favorable microenvironment for its survival.
Step 5
i. What is a vaccine?
Answer
A vaccine is a biological preparation that provides active acquired immunity to a particular infectious disease. It typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe or its toxins.
Step 6
ii. How would the vaccine protect against infection by Helicobacter pylori?
Answer
The vaccine against Helicobacter pylori would stimulate the immune system to recognize and fight the bacterium. By introducing the antigen into the body, the immune system produces antibodies and memory cells, which prepare it to react swiftly upon future exposure to the actual pathogen.
Step 7
iii. Explain why this vaccine is unlikely to protect against infection by other bacteria as well as its action against Helicobacter pylori.
Answer
This vaccine is unlikely to provide protection against other bacteria because vaccines are typically specific to particular pathogens. The immune response generated by a vaccine against Helicobacter pylori is tailored to recognize and respond to this specific bacterium, and it may not be effective against other species that have different antigens or mechanisms of infection.