IB Biology Paper 2 Topics

Photosynthesis

The process by which plants convert light energy into chemical energy to synthesize organic compounds.

Natural Selection

The mechanism by which beneficial traits become more common in a population over time due to differential reproduction.

ICEAGE

The process of antibiotic resistance development in bacteria due to the survival and proliferation of resistant strains.

Defense against disease

The immune system's multi-layered response to prevent and combat infections in the body.

Replication/transcription/translation

The processes of DNA replication, RNA transcription, and protein translation in cells.

Stem cells

Undifferentiated cells capable of developing into various cell types, used in regenerative medicine.

Mitosis/Meiosis

Cell division processes - mitosis for growth and repair, meiosis for gamete formation.

Cell membrane structure

The composition and functions of proteins in the cell membrane.

Action Potential

Rapid changes in membrane potential during neuron firing, involving depolarization, repolarization, and refractory periods.

Small intestine

The organ responsible for absorbing nutrients from digested food, with specialized structures like villi and microvilli.

Arteries/Veins

Blood vessels with distinct functions - arteries carry blood away from the heart under high pressure, while veins return blood to the heart under low pressure.

Veins

Blood vessels with a wide lumen relative to wall thickness to maximize blood flow and contain less muscle and elastic fibers due to low pressure.

Valves

Structures in veins that prevent backflow of blood and pooling at extremities due to low pressure.

Skeletal muscles

Muscles that contract and squeeze veins to aid blood flow against gravity.

Energy flow in ecosystems

Process where plants convert solar energy to chemical energy through photosynthesis, which is passed on to organisms through feeding and lost as heat energy.

Trophic levels

Positions in the food chain where energy is transferred, with about 10% efficiency between levels.

Nutrient cycling

Process where autotrophs convert inorganic nutrients to organic compounds, heterotrophs consume them, and saprotrophs decompose remains to return inorganic nutrients to the soil.

GMOs

Genetically Modified Organisms with benefits like increased crop yield but risks like environmental impact and unknown long-term effects.