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In a certain country, 25 000 individuals were suffering from haemophilia between 2012 and 2020 - NSC Life Sciences - Question 3 - 2024 - Paper 2
Question 3
In a certain country, 25 000 individuals were suffering from haemophilia between 2012 and 2020. Haemophilia is a genetic disorder that is caused by a mutation. The ... show full transcript
Worked Solution & Example Answer:In a certain country, 25 000 individuals were suffering from haemophilia between 2012 and 2020 - NSC Life Sciences - Question 3 - 2024 - Paper 2
Step 1
Explain the effect of this mutation on an individual.
Answer
The mutation that causes haemophilia affects an individual's ability to clot blood effectively. This can lead to excessive bleeding from even minor injuries, internal bleeding, and swelling in joints. Individuals with haemophilia may also experience complications like bruising and may require treatments to manage their condition.
Step 2
Calculate the number of individuals who were moderately affected by haemophilia in this country. Show ALL working.
Answer
To find the number of individuals moderately affected by haemophilia, we use the percentage from the pie chart:
- Total individuals with haemophilia = 25,000
- Percentage moderately affected = 25%
Calculating the number:
ext{Moderate cases} = rac{25}{100} imes 25000 = 6250
So, there are 6,250 individuals who were moderately affected.
Step 3
Explain why it would be expected that most of the individuals affected by haemophilia will be males.
Answer
Haemophilia is primarily linked to the X chromosome, meaning that it is an X-linked recessive disorder. Males have only one X chromosome (XY), so if they inherit the recessive allele for haemophilia, they will express the disorder since there is no second X chromosome to mask it. In contrast, females have two X chromosomes (XX), so they would need to inherit the recessive allele from both parents to be affected, making it statistically more likely for males to be affected by haemophilia.