Criterion D places biology in the world. You explain how a biological idea is used, then discuss who benefits, who is at risk and what a fair decision might look like.
You explain the science behind a specific real-world solution or issue.
You weigh benefits and drawbacks for people, society, the economy or the environment.
Precise terms, units and symbols, used correctly and in context.
Every idea or figure from someone else is referenced with a recognised convention.
A little of the criterion is addressed. Ideas are basic, partly missing, or not linked to the task.
The main points are there but thin. Some explanations are correct; links to the task or evidence are incomplete.
Mostly accurate, well explained and consistently tied to the task, with only small gaps.
Detailed, precise and justified throughout, with ideas connected and applied to new situations or evidence.
A plain-language guide only. Your teacher marks against the official IB level descriptors.
Discuss the use of antibiotics in farming.
Antibiotics keep animals healthy but they make bacteria resistant, which is bad.
Antibiotics kill bacteria that cause disease, so farmers use them to keep animals healthy and produce more meat (Source 1). Using them routinely, however, puts selection pressure on bacteria: resistant individuals survive and reproduce, so resistance becomes more common and can pass to bacteria that infect humans. A fairer approach is to use antibiotics only to treat diagnosed illness, which protects animal welfare and keeps medicines effective.
Criterion D is Reflecting on the impacts of science. It is marked out of 8 across 4 strands (D.i, D.ii, D.iii, D.iv). Criterion D places biology in the world. You explain how a biological idea is used, then discuss who benefits, who is at risk and what a fair decision might look like.
Choose a defined case such as antibiotic resistance, GM crops or vaccination programmes. Explain the biology of how it works before you discuss its consequences. Include ethical, social and environmental implications and weigh them.
Treating a debate as one-sided without evidence on the other view. Confusing selective breeding with genetic modification. Citing websites with no author or date and no checking of reliability.
Written by CritABCD for study and revision, in our own words. The official MYP Biology guide and assessment criteria are published by the International Baccalaureate. Official IB guide ↗