Summary and Key Take Aways for Pearson Edexcel International Advanced Level
for use with Question 8 – Unit 5, June 2025
In unit 5, the last question (question 8) is based on a pre-released scientific article a total of 30
marks.
In this document, you will find a summary and the key takeaways for the Scientific Article for
question 8 for Biology IAL (International Advanced Level) WBI15/01.
(The article is provided by Pearson Edexcel Examination – June 2025)
This document consists of
o Article Summary (258 words)
o Concise Summary of 52 words
o Summary of each sub-section of the article
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 Five (5) Key Take aways for each of the 2 sub-articles
o One (1) Key Take away for each paragraph
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, WBI15/01– Article Summary and Key Take Aways Biology A Level Tutor
Entire Article Summary
Summary of the article (258 words):
The article presents two interrelated pieces of research focused on the Y chromosome’s impact
on men’s health and its evolutionary journey. The first article investigates how the loss of the Y
chromosome in immune cells, a phenomenon that becomes more common with age, may
contribute to increased heart disease risk. Researchers observed that a significant proportion of
older men exhibit Y chromosome loss in their immune cells, and experimental removal of the Y
in mice led to heart muscle scarring and subsequent cardiac dysfunction. Analysis of data from
the UK Biobank further revealed that men with extensive Y loss had a markedly higher risk of
circulatory disease mortality over a 12‐year period. The study identified that immune cells
missing the Y infiltrate heart tissue and trigger the release of inflammatory molecules, such as
transforming growth factor beta, which exacerbates heart damage. An antibody blocking this
pathway showed potential in reducing harm, suggesting new therapeutic avenues.
The second article explores the evolution and significance of the Y chromosome. Despite its
gradual loss of genetic material over 180 million years, the modern Y retains crucial genes that
are largely involved in sperm production and gene regulation. Contrary to earlier predictions of
its eventual disappearance, evidence now shows that gene loss on the Y has plateaued, with
essential regulatory genes conserved across diverse mammalian species. Together, these findings
illustrate a dual narrative: while the loss of the Y chromosome in certain cells can be detrimental
to health, the remaining genes are so vital that they have been preserved through evolutionary
pressures.
The summary of the summary is (52 words):
The article links age-related Y chromosome loss in immune cells to increased heart disease
risk. Experimental Y removal in mice led to heart scarring, while human data correlated extensive
loss with higher circulatory mortality. In parallel, research on Y evolution reveals a plateau in
gene loss, preserving essential genes for male health.
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