A-Level Edexcel Biology AS Sampling Scientific Data

A-Level Edexcel Biology AS Sampling Scientific Data
Pearson Edexcel International Advanced Subsidiary/Advanced Level in Biology, Issue 2, February 2021Biology XBI11/YBI11

Review A-Level Edexcel Biology sampling scientific data through the available evidence on estimated figures, incomplete testing and false results.

How this is tested

  • explain why biological figures are estimates when not everyone is tested or results are false

Question 5(b)(i)

[Maximum number: 2]

Mycobacterium tuberculosis (Mtb) and human immunodeficiency virus (HIV) are two pathogens that infect people. When people infected with either pathogen become infected with the other pathogen the disease is worse.

In one year, it was estimated that 33.4 million people were infected with HIV. It was estimated that 30% of these people were also infected with M t b.

Suggest two reasons why these figures are only estimates.