Chapter 1 — The Study of Life (Vocabulary Flashcards)

Vocabulary flashcards covering key terms from the notes on Chapter 1: The Study of Life.

Biosphere

The largest, most inclusive level of biological organization that includes all ecosystems and living organisms on Earth.

Organism

An individual living thing that has the characteristics of life and can carry out life processes.

Atom

The basic unit of matter; the smallest unit of an element that retains its properties.

Molecule

A chemical structure consisting of two or more atoms bonded together.

Cell

The fundamental unit of life; the smallest unit that can carry out all life’s processes.

Tissue

A group of similar cells performing a common function (e.g., nervous tissue).

Organ

A structure composed of two or more tissues that performs a specific function.

Organ System

A group of organs working together to perform large physiological functions.

Producer

An organism that captures energy from the sun (or inorganic sources) and stores it as chemical energy (glucose); plants are producers.

Consumer

An organism that obtains energy by feeding on other organisms.

Decomposer

An organism, such as certain fungi or bacteria, that breaks down dead matter into simpler compounds.

ATP

Adenosine triphosphate; the cell’s main energy currency.

Glucose

A simple sugar produced by photosynthesis and used as an energy source by cells.

Photosynthesis

Process by which producers convert light energy into chemical energy (glucose), releasing oxygen.

Homeostasis

The maintenance of a relatively stable internal environment in the face of external changes.

Stimulus

Anything in the environment that triggers a response from an organism.

Response

The reaction of an organism to a stimulus.

Adaptation

A heritable trait that improves an organism’s ability to survive and reproduce in a particular environment.

Natural Selection

The process by which individuals with advantageous traits reproduce more successfully, increasing those traits in a population.

Evolution

Change in the frequencies of traits in a population over generations.

Common Ancestor

A shared predecessor from which two or more lineages descend.

Domain

The highest taxonomic rank; the three domains are Bacteria, Archaea, and Eukarya.

Bacteria

A domain consisting of prokaryotic microorganisms; among the three domains.

Archaea

A domain of prokaryotic microorganisms often living in extreme environments.

Eukarya

A domain whose organisms have eukaryotic cells; includes protists, plants, fungi, and animals.

Protists

A diverse group of mostly single-celled eukaryotes within Eukarya; not plants, fungi, or animals.

Plants

A kingdom within Eukarya; multicellular, photosynthetic producers.

Fungi

A kingdom within Eukarya; mostly decomposers that absorb nutrients from their surroundings.

Animals

A kingdom within Eukarya; multicellular, heterotrophic, usually mobile organisms.

DNA

Deoxyribonucleic acid; the molecule that stores genetic information in cells.

Nucleotides A T C G

The four building blocks of DNA: adenine (A), thymine (T), cytosine (C), guanine (G).