Biology: Characteristics and Classification of Living Organisms

These flashcards cover key concepts from the lecture notes on biology, specifically focusing on the characteristics and classification of living organisms and related biological processes.

MRS GREN

An acronym representing the seven characteristics of living organisms: Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition.

Movement

Action by an organism or part of an organism causing a change of position or place.

Respiration

Chemical reactions in cells that break down nutrient molecules to release energy for metabolism.

Sensitivity

Ability to detect or sense stimuli in the internal or external environment and to make appropriate responses.

Growth

Permanent increase in size and dry mass by an increase in cell number or cell size or both.

Reproduction

Processes that make more of the same kind of organism.

Excretion

Removal from organisms of the waste products of metabolism, toxic materials, and substances in excess of requirements.

Nutrition

Taking in of materials for energy, growth, and development.

Binomial System

A system of naming organisms with their Genus (capitalized) and species (lowercase).

Species

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

Organelle

Structures within a cell that perform specific functions, such as the nucleus, mitochondria, ribosomes, and chloroplasts.

Prokaryotes

Single-celled organisms that lack membrane-bound organelles, such as mitochondria.

Diffusion

Net movement of particles from a region of higher concentration to lower concentration as a result of their random movement.

Osmosis

Net movement of water molecules from a region of higher water potential to lower water potential across a partially permeable membrane.

Active Transport

Movement of particles against a concentration gradient using energy.

Turgid

A plant cell that is tight and firm due to high internal water pressure against the cell wall.

Biological Catalysts

Substances that speed up chemical reactions in the body without being changed, such as enzymes.

Lock and Key Mechanism

A model describing how enzymes and substrates fit together to form an enzyme-substrate complex.

Anaerobic Respiration

A type of respiration that occurs without oxygen, producing less energy than aerobic respiration.

Pathogen

A disease-causing organism.

Immunity

The ability of the body to resist or eliminate disease-causing organisms or pathogens.

Sustainable Development

Providing for the needs of an increasing human population without harming the environment.