Biology: Levels of Organization, Populations, Species, and Core Concepts

Flashcards covering key terms from the notes on organs, tissues, populations, species, communities, ecosystems, cell biology, metabolism (anabolic processes), photosynthesis, energy flow, and core scientific concepts like hypothesis, theory, and homeostasis.

Organ

A structure made up of tissues that works together to perform a specific function in the body (organs are formed from four major tissue types).

Tissue

A group of cells that cooperate to perform a common function.

Organ system

A group of organs that work together to perform complex life processes for the organism.

Population

All the members of the same kind of living thing (same species) living in a defined area.

Species

A group of organisms that can interbreed and produce viable fertile offspring.

Population in a defined area

All individuals of a species living in a specific geographic area.

Community

All populations of different species living in the same area.

Ecosystem

A community and its physical environment; the living and nonliving components in a particular area.

Unicellular

An organism composed of a single cell.

Plasma membrane

The cell membrane that encloses the cell, separating its contents from the outside and regulating substance movement.

Metabolism

The total set of chemical reactions that occur in an organism.

Anabolic

Reactions that build larger molecules from smaller ones, usually requiring energy.

Photosynthesis

The process by which plants convert sunlight, CO2, and water into glucose and oxygen.

Glucose

A simple sugar (C6H12O6) produced by photosynthesis and used as an energy source.

Cell division

The process by which a cell divides to form new cells; includes mitosis and meiosis.

Mitosis

A type of cell division that produces two genetically identical diploid daughter cells.

Meiosis

A type of cell division that produces four genetically distinct haploid gametes.

Hypothesis

A testable educated guess about how something works.

Theory

A well-supported explanation of natural phenomena that can be revised with new evidence; not just a guess.

Homeostasis

Maintenance of a stable internal environment in an organism.

Physiology

The study of how the parts of an organism function and what they do.

Energy

The capacity to do work; in biology, energy comes from food and sunlight.

Sun (as energy source)

Primary energy source for most life on Earth, captured during photosynthesis.

Carbon dioxide (CO2)

A waste product of metabolism and a reactant in photosynthesis.

Water (H2O)

A reactant in photosynthesis and a product of various metabolic processes.

Organelles

Miniature functional units inside a cell that carry out specific tasks; the whole cell is alive when organelles work together within a membrane.