Augment’s own questions for Biology, written in the style of IB exams, each with its markscheme. They are not past papers. One from each topic is below to try.
Every question has a markscheme.
The paper each question is written for, so you can practice one paper at a time.
Each topic in syllabus order, with its subtopics. Lines with notes link to them. Under each topic is one question to try, its markscheme folded until you open it.
Why is water described as the medium for life?
The answer is B.
The first cells are thought to have arisen in water, and most metabolic processes still take place in aqueous solution, so water is the medium for life. A is wrong because many other molecules (DNA bases, proteins, sugars) form hydrogen bonds. C confuses the medium with an energy source: water releases no usable energy. D is wrong because water is an inorganic molecule.
Which row describes the changes in the bands of a sarcomere when a skeletal muscle fibre contracts?
Row | A band | I band | H zone |
|---|---|---|---|
A | shorter | shorter | shorter |
B | unchanged | unchanged | shorter |
C | unchanged | shorter | shorter |
D | shorter | unchanged | unchanged |
The answer is C.
The A band is the length of the myosin (thick) filaments, which do not change length, so it stays the same. As actin filaments slide towards the centre, the regions containing only actin (I band) or only myosin (H zone) both narrow. Row A assumes the filaments themselves shorten; row B forgets that the I band narrows as the Z lines move closer to the thick filaments.
What is the main benefit to a cell of having enzymes that act as catalysts?
The answer is A.
Catalysts increase the rate of reactions without being used up, so metabolic reactions happen quickly enough to sustain life at the relatively low temperatures found in cells. Enzymes do not supply energy (B); they lower the activation energy. They do not change the amount of product at equilibrium (C), and they do not heat the cell (D).
Which process in a multicellular organism depends on DNA replication?
The answer is C.
New cells for growth and tissue replacement are produced by cell division, and each new cell needs an exact copy of the DNA, so the DNA must be replicated first. A and D involve translation and secretion of proteins, and B is transcription; none of these requires the DNA to be copied.
A free account opens the whole question bank, keeps a record of what you have marked, and builds worksheets from the topics you pick.