Biology igcse

Function of the Nucleus

Contains the genetic material (DNA) of the cell and controls its activities.

Function of the Mitochondria

The site of aerobic respiration, where energy (ATP) is released for the cell.

Diffusion

The net movement of particles from an area of higher concentration to an area of lower concentration down a concentration gradient.

Osmosis

The net movement of water molecules from a region of higher water potential to a region of lower water potential across a partially permeable membrane.

Active Transport

The movement of substances against a concentration gradient (from low to high concentration) using energy from respiration.

Enzyme

A biological catalyst that speeds up the rate of chemical reactions in cells without being used up.

Word Equation for Photosynthesis

Carbon dioxide + Water \rightarrow Glucose + Oxygen (in the presence of light and chlorophyll).

Balanced Chemical Equation for Aerobic Respiration

C{6}H{12}O{6} + 6O{2} \rightarrow 6CO{2} + 6H{2}O + Energy

Role of the Xylem

Transports water and mineral ions from the roots to the leaves of the plant.

Homeostasis

The maintenance of a constant internal environment, such as regulating body temperature or blood glucose levels.

Transpiration

The evaporation of water from the surface of a plant, primarily through the stomata in the leaves.

Pathogen

A microorganism that causes disease (e.g., bacteria, viruses, fungi, or protoctists).

Double Circulation

A circulatory system where blood passes through the heart twice for every complete circuit of the body.

Mutation

A rare, random change in the genetic material (DNA) that can be inherited.

Ecosystem

A distinct self-supporting system of organisms interacting with each other and with their physical (abiotic) environment.