IB Biology

A Unity and Diversity

A1.1 Water

A1.2 Nucleic acids

A2.1 Origins of cells

A2.2 Cell structure

A2.3 Viruses [HL only]

A3.1 Diversity of organisms

A3.2 Classification and cladistics [HL only]

A4.1 Evolution and speciation

A4.2 Conservation of biodiversity

B Form and Function

B1.1 Carbohydrates and lipids

B1.2 Proteins

B2.1 Membranes and membrane transport

B2.2 Organelles and compartmentalization

B2.3 Cell specialization

B3.1 Gas exchange

B3.2 Transport

B3.3 Muscle and motility [HL only]

B4.1 Adaptation to environment

B4.2 Ecological niches

C Interaction and Interdependence

C1.1 Enzymes and metabolism

C1.2 Cell respiration

C1.3 Photosynthesis

C2.1 Chemical signalling [HL only]

C2.2 Neural signalling

C3.1 Integration of body systems

C3.2 Defence against disease

C4.1 Populations and communities

C4.2 Transfers of energy and matter

D Continuity and Change

D1.1 DNA replication

D1.2 Protein synthesis

D1.3 Mutation and gene editing

D2.1 Cell and nuclear division

D2.2 Gene expression [HL only]

D2.3 Water potential

D3.1 Reproduction

D3.2 Inheritance

D3.3 Homeostasis

D4.1 Natural selection

D4.2 Stability and change

D4.3 Climate change

Question rangeC1.3.14 (HL)—Thylakoids as light-dependent systems

[Maximum number: 1]

The diagram shows the structure of a chloroplast. Where does the Calvin cycle occur?

[Maximum number: 1]

Which products of the light-dependent reactions are used in the Calvin cycle?

$\mathrm{O}_{2}$ and hydrogen ions

ATP and $\mathrm{CO}_{2}$

Electrons and reduced NADP

ATP and reduced NADP

C1. Sour orange trees (Citrus aurantium L.) were grown outdoors in Phoenix, Arizona (USA) in chambers with clear plastic sides and open tops. These chambers were continuously maintained at mean atmospheric $\mathrm{CO}_{2}$ concentrations of either 400 or 700 ppm (parts per million) for several years. Both the rate of $\mathrm{CO}_{2}$ absorption of sunlit leaves and the temperature of the leaves were measured on some of the hottest days.