Check your understanding

Use these short prompts to self-test. Try to answer before you reveal the sample response.

Heredity and evolution (U01–U02)

1. Why does meiosis matter for genetic diversity?
   Sample answer: It forms gametes with new combinations of alleles and half the chromosome number so sexual reproduction mixes parental DNA.

2. Name one type of evidence for evolution.
   Sample answer: Fossil sequences; homologous structures; molecular similarities in DNA across species.

Universe and climate (U03–U04)

1. What is one piece of evidence linked to the Big Bang model?
   Sample answer: Cosmic microwave background radiation; or redshift of distant galaxies.

2. Name two of Earth’s major spheres involved in climate models.
   Sample answer: Atmosphere and hydrosphere (also geosphere, biosphere).

Motion and forces (U05)

1. State Newton’s second law in words and as an equation.
   Sample answer: Acceleration is proportional to net force and inversely proportional to mass; .

Atoms and reactions (U06–U07)

1. What is a decomposition reaction?
   Sample answer: One reactant breaks into two or more simpler products.

Human endeavour (H01–H04)

1. Why is peer review useful?
   Sample answer: Independent experts check methods and claims to improve quality before ideas spread widely.

Inquiry (I01–I08)

1. What makes an investigation more reproducible?
   Sample answer: Clear written methods, controlled variables, appropriate repetition/sample size, and consistent use of equipment.

2. Why cite sources for secondary data?
   Sample answer: So others can verify the information, credit the original authors, and judge reliability.

For multiple-choice practice, see the quiz index.