Potential questions for Pearson Edexcel Biology A (Salters Nuffield)
for use with Question 8 – Paper 3, June 2026
In paper 3, the last question (question 8) is based on a pre-released scientific article a total of 30
marks.
In this document, you will find the following in relation to the Scientific Article for question 8 for
Biology A (Salters Nuffield) 9BN0/03:
o Article Summary (258 words) and a more concise version of 50 words
o Five (5) Key Takeaways for the entire article (these are the things you should know and
understand from this article before the exam).
o Vocabulary and Definitions of unknown words for each paragraph
o Key Take aways for each paragraph
o 312 potential questions each with its answer
➢ The questions are based on the scientific article
➢ 90% of them are linked to the syllabus, thus this document can be used for
revision as well
The article is available at the end of this booklet.
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,9BN0/03 – Article potential questions Biology A Level Tutor
Summary of the article (258 words):
The article explains that venom neurotoxins are widespread across the animal kingdom because
venom is a highly effective biological tool for catching prey, deterring predators, and sometimes
competing with members of the same species. These toxins disrupt the nervous system, especially
at the neuromuscular junction, where nerve impulses trigger muscle contraction. By interfering
with this process, neurotoxins can either overstimulate muscles, causing spasms or continuous
contraction, or block signalling entirely, causing paralysis. Paralysis is particularly dangerous
because it can stop breathing when the diaphragm no longer functions.
The article describes several ways venom achieves these effects. Some toxins block sodium
channels in neurones, preventing action potentials and stopping muscle contraction. Others keep
sodium channels open, causing excessive nerve activity. Additional toxins interfere with potassium
or calcium channels, or block acetylcholine receptors on muscle cells. Together, these examples
show that venomous animals have evolved multiple precise ways to attack essential physiological
systems.
The article then discusses antivenom, the main specific treatment for venomous bites. Antivenom
is usually produced by exposing a large animal such as a horse to small, increasing doses of venom
and then extracting the antibodies formed. The authors note that similarities between toxins in
different species may allow the development of broader, more economical antivenoms. However,
access remains a major problem, especially in poor rural communities in tropical and subtropical
regions.
Finally, the article argues that venom neurotoxins may also benefit humans. Because they act very
specifically on physiological systems, they may inspire or become medicines for conditions such as
pain, epilepsy, cerebral palsy, multiple sclerosis.
The summary of the summary is (50 words):
Venom neurotoxins evolved widely because they help animals capture prey and defend
themselves. They disrupt neuromuscular signalling by targeting ion channels or receptors, causing
spasms, paralysis and respiratory failure. The article also explains antivenom production, access
problems, and the medical promise of highly specific venom-derived drugs for future human
therapies.
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,9BN0/03 – Article potential questions Biology A Level Tutor
5 Key Take Away for the entire article:
• Venom evolved because it is highly useful for survival: Many animals use venom to catch
prey, defend themselves, and sometimes compete with members of their own species. Its
widespread appearance across the animal kingdom shows that it is a very successful
evolutionary tool.
• Neurotoxins are dangerous because they disrupt the nervous system at vital points: The
article focuses on how venom neurotoxins attack the neuromuscular junction, either
causing excessive muscle contraction or preventing muscles from contracting at all. This
can lead to paralysis, including paralysis of the diaphragm, which stops breathing.
• Venoms can act in several precise biological ways: Different toxins target sodium,
potassium, and calcium ion channels, or block acetylcholine receptors. This shows that
venomous animals have evolved multiple highly specific mechanisms to interfere with
normal body regulation.
• Antivenom is essential, but access is still a major global problem: Antivenom is made by
stimulating antibody production in animals such as horses, then using those antibodies to
neutralise venom in humans. However, the article stresses that supply, distribution, and
affordability remain serious challenges, especially in poor rural tropical regions.
• Venom research could help create future medicines: Because venom toxins act very
specifically on physiological systems, they may inspire or become treatments for human
disorders. The article highlights possible medical uses in areas such as pain, epilepsy,
cerebral palsy, and multiple sclerosis.
More concise:
• Venom is a powerful survival tool: It helps animals catch prey, defend themselves, and
sometimes compete with their own species.
• Neurotoxins disrupt vital nerve signalling: They affect the neuromuscular junction, causing
spasms, paralysis, and sometimes breathing failure.
• Venoms act through precise mechanisms: Different toxins target ion channels or
acetylcholine receptors to disrupt normal body function.
• Antivenom is vital but hard to access: It can neutralise venom, but cost, supply, and
distribution remain major problems.
• Venom research may lead to new medicines: Its highly specific toxins could help treat
disorders such as pain, epilepsy, and multiple sclerosis.
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, 9BN0/03 – Article potential questions Biology A Level Tutor
Questions, Answers, Vocabulary per Paragraph:
Paragraph 1:
Diversity — a wide variety of different kinds.
Inject — force a substance into the body, usually through a bite, sting, or similar wound.
Venom — a toxic secretion made by an animal and delivered into another animal through a wound.
Incapacitate — make unable to move, escape, or function normally.
Prey — an animal hunted and eaten by another animal.
Repel — drive away or keep off.
Paralysis — loss of the ability to move muscles.
Neurotoxins — toxins that affect the nervous system.
Interfere with — disturb or prevent a normal process from happening.
Paragraph Takeaway: Venom neurotoxins are common in many animals, where they harm nerves
to cause effects such as pain, paralysis, and breathing failure, but they may also help scientists
develop new medicines.
1. Why do many animals inject venom into other animals?
o To incapacitate prey
o To repel predators
o To improve survival by affecting another animal’s body systems
2. What kinds of effects can venom have on a victim?
o Paralysis
o Prevention of breathing
o Pain
3. What are neurotoxins?
o Molecules in venom that interfere with nerve function
o They affect the nervous system
o Although harmful, they may also help in developing new drugs
4. The venom from some species of snake contains enzymes that affect the blood clotting
process.
(a) (i) Which is a correct statement about enzymes? (1)
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