Characteristics of Living Organisms and Classification

Vocabulary flashcards covering the seven characteristics of living organisms (MRS GREN), non-living characteristics of viruses, species definition, binomial naming system rules, and DNA-based classification trees.

Movement

An action done by an organism or part of an organism causing a change of position or place.

Respiration

The chemical reaction taking place inside living cells where nutrient molecules are broken down to release energy for metabolism.

Sensitivity

The ability to detect and respond to changes in the internal or external environment.

Growth

A permanent increase in size and dry mass.

Excretion

The removal of the waste products of metabolism and substances in excess of requirements outside the body.

Reproduction

The processes by which living organisms make more of the same kind (species).

Nutrition

Taking in nutrients for growth and development, repair of tissues & energy.

Viruses

Entities considered non-living by biologists because they are not cells, do not grow or respond to surroundings or stimuli, cannot make/take in food or produce wastes, and can only multiply inside another living cell.

Classification systems

Systems that classify living organisms into groups according to shared features, aiming to reflect evolutionary relationships.

DNA base sequences (in classification)

Sequences used as an accurate means of classification; organisms sharing a more recent ancestor have base sequences in DNA that are more similar than those sharing a distant ancestor.

Species

A group of organisms that can reproduce to produce fertile offspring.

Binomial system

An internationally agreed system of naming species in which the scientific name of an organism is made up of two parts showing the genus and species in Latin.

Binomial naming formatting rules

Scientific names are written in Latin and italicized, where the Genus name starts with a capital letter and the species name starts with a small letter.

Genus relationship rule

If two organisms have the same genus but different species, they are closely related; if they have different genera but the same species name, they are not closely related.

Classification tree

A diagram used to trace ancestry; organisms sharing a more recent ancestor have the shortest distance from the branching point and share more similar DNA base sequences.

Most Recent Common Ancestor (MRCA)

The most recent ancestor from which a group of organisms descended, indicated at branching nodes on a classification tree.