the study of life

Biology

The study of life.

Science

Knowledge that observes general truths or the operation of general laws.

Scientific knowledge

Method of research with defined steps that include experiments and careful observation.

Hypothesis

Suggested explanation for an event which one can test.

Theory

Tested and confirmed explanation for observations and phenomena.

Scientific reasoning

Inductive reasoning (particular → general).

Deductive reasoning

Form of logical thinking that uses a general principle or law to predict specific results.

Scientific method

Starts with observation (problem to solve) → form a question → propose hypothesis → test hypothesis; has to be testable and falsifiable.

Properties of life

Seven properties of living organisms including order, sensitivity/response to environment, reproduction, adaptation, growth and development, regulation/homeostasis, energy processing, and evolution.

Levels of organization

Atom → molecule → macromolecules → organelles → cell → prokaryotes → eukaryotes → tissue → organs → organ system → organisms → population → community → ecosystem → biosphere.

taxonomy

science of identifying and classifying organisms (according to evolutionary relationships)

anabolism

building of complex molecules from numerous simple ones (eg. protein synthesis)

catabolism

breakdown of complex molecules into numerous simple ones (eg. break down of glucose)

discovery of penicillin

In 1928 Dr Alexander Fleming returned from a holiday to find mould growing on a Petri dish of Staphylococcus bacteria. He noticed the mould seemed to be preventing the bacteria around it from growing. He soon identified that the mould produced a self-defence chemical that could kill bacteria. (used the scientific method, he had a question, created a hypothesis, had a prediction and tested it)

chi square test

compares observed frequencies in each category to expected frequencies based on the null hypothesis. A high value indicates a greater difference between observed and expected data if it exceeds the critical value, null must be rejected.

radioisotopes

unstable form of a chemical element that releases radiation as it breaks down and becomes more stable