IB Biology Notes (SL)

Water

The substance necessary for life processes, involved in many biological functions.

Metabolism

The sum of a cell’s chemical reactions that occur in liquid water.

Polar covalent bond

A bond formed when two atoms with different electronegativities share electrons unequally.

Cohesion

Water's attraction to itself, leading to surface tension.

Adhesion

Water's attraction to other polar substances.

Hydrophilic

Substances that are polar and charged and interact with water.

Hydrophobic

Non-polar substances that do not interact with water and tend to repel it.

Buoyancy

The upward force exerted by a fluid on an object immersed in it.

Specific heat capacity

The quantity of energy required to change the temperature of a given amount of a substance.

Nucleic acids

Polymers of nucleotides; DNA and RNA, responsible for genetic information.

Transcription

The process of synthesizing RNA from a DNA template.

Translation

The process of synthesizing a protein from an mRNA template.

Chloroplasts

Organelles in plant cells where photosynthesis occurs.

Aerobic respiration

Respiration that requires oxygen and produces carbon dioxide and water as waste.

Anaerobic respiration

Respiration that occurs in the absence of oxygen, producing lactate or ethanol.

Gene mutation

A change in the DNA sequence of a gene.

Homeostasis

The maintenance of stable internal conditions in an organism.

Natural selection

The process through which populations evolve as advantageous traits become more common.

Evolution

The change in the heritable characteristics of biological populations over successive generations.

Biodiversity

The variety of life in the world or in a particular habitat or ecosystem.

Ex situ conservation

Conservation methods that involve maintaining species outside their natural habitats.

In situ conservation

Conservation methods that involve protecting species in their natural habitats.