Characteristics of Living Organisms

A set of vocabulary flashcards based on the characteristics of living organisms for Edexcel IGCSE Biology.

MRS C GREN

A mnemonic for the unifying characteristics of living organisms: Movement, Respiration, Sensitivity, Control, Growth, Reproduction, Excretion, Nutrition.

Autotrophic

Organisms that produce their own food, typically via photosynthesis, like plants.

Heterotrophic

Organisms that obtain energy by consuming other living things, such as animals.

Respiration

A metabolic process in which organisms release energy from glucose; can be aerobic or anaerobic.

Excretion

The process of removing toxic waste products from an organism.

Homeostasis

The maintenance of a stable internal environment within an organism.

Metabolic Reactions

Chemical reactions that occur within living cells to maintain life.

Photosynthesis

The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll.

Viruses

Microorganisms that are not considered living as they cannot carry out metabolic processes independently.

Pathogen

A microorganism that causes disease, such as bacteria, viruses, fungi, or protoctists.

Protoctists

A diverse group of microscopic, primarily unicellular organisms that do not fit into the other kingdoms of life.

Prokaryotic Organisms

Single-celled organisms without a nucleus, such as bacteria.

Eukaryotic Organisms

Organisms whose cells contain a nucleus, including animals, plants, fungi, and protoctists.

Fungi

A kingdom of organisms that typically have cell walls made of chitin and obtain nutrients through saprotrophic nutrition.

Thermoregulation

The process of maintaining an optimal body temperature.

Asexual Reproduction

A form of reproduction that involves a single parent producing genetically identical offspring.

Sexual Reproduction

A reproductive process that involves the fusion of male and female gametes.

Chloroplast

An organelle in plant cells where photosynthesis occurs.

Cytoplasm

A gel-like substance inside cells where many cellular processes occur.

Nucleus

The membrane-bound organelle that contains the genetic material in eukaryotic cells.

Bacteria

Single-celled prokaryotic organisms that can be beneficial or pathogenic.