Principles of Biology

The genetic changes in a population over generations.

A process where some individuals of a population have genetically based traits that cause them to better survive and produce more offspring than other individuals.

A basic unit of living matter separated from its environment by a plasma membrane. Cells are the fundamental structural untis of life.

Lacks a nucleus and other mebranne-enclosed organelles. Found only in bacteria and archaea.

Has a membrane-enclosed nucleus and other membrane-enclosed organelles. All organisms except bacteria and archaea are composed of eukaryotic cells.

single-celled eukaryotic organisms, eg amoeba and protozoans

• Movement: eg locomotion of turning leaves towards the sun.
• Respiration: converting food into stored chemical energy.
• Sensitivity to stimuli: any action that occurs as a result of a change in the local environment.
• Growth: by assimilating materials from food.
• Reproduction: sexually (by combination of two gametes), or asexually (eg tapeworm/budding, plants/runners)
• Excretion: mainly CO₂.
• Nutrition: utilise energy.

• 1920s. First put forward the hypothesis that conditions on early Earth could have generated organic molecules.
• Note: Miller later confirmed this hypothesis (1953).

• Proved that complex organic molecules can form spontaneously under conditions that probably existed on the early earth.
• Demonstrated the kinds of molecules that could have been produced on the early earth.

a, d, b, c (check)

• Lightening
• UV radiation
• volcanic eruptions