Unit A: Energy and Matter Exchange in the Biosphere 20%

Overview: The constant flow of energy and cycling of matter in the biosphere leads to a balanced or

steady state. This balance is achieved through various biogeochemical cycles and the processes of

photosynthesis and cellular respiration.

Unit B: Ecosystems and Population Change 25%

Overview: Overview: In this unit, students become familiar with a range of ecosystems by studying their

distinctive biotic and abiotic characteristics. Students are introduced to the concept of populations as a

basic component of ecosystem structure and complete the unit by examining population change through

the process of natural selection.

Unit C: Photosynthesis and Cellular Respiration 15%

Overview: The life processes of photosynthesis and cellular respiration allow for the transfer of energy

and matter. Students learn, in general terms, how energy from sunlight is transferred into adenosine

triphosphate (ATP) and reduced nicotinamide adenine dinucleotide phosphate (NADPH) and eventually

into glucose, and how carbohydrates are oxidized to produce reduced nicotinamide adenine dinucleotide

(NADH), reduced flavin adenine dinucleotide (FADH) and eventually ATP. Detailed knowledge of

metabolic intermediates is not required.

Unit D: Human Systems 40%

Overview: Maintenance of metabolic equilibrium in organisms involves a number of physical and

biochemical processes. The human organism is used as a model system to examine how energy and

matter are exchanged with the environment through the processes of gas exchange, digestion, excretion,

circulation, and the function of the motor system. A defence system contributes to equilibrium by

eliminating pathogenic organisms.