Comprehensive Biology Review: Characteristics of Life, Organization, Life Processes, and Classification

Vocabulary practice flashcards covering the key terms, biological principles, levels of organization, human and plant physiological processes, cellular respiration, and taxonomic classification systems from the lecture study summaries.

Cell

The smallest unit of life and the basic unit of structure and function in all living things.

Unicellular Organism

An organism that is made up of a single cell, such as a bacterial cell.

Multicellular Organism

An organism that is made up of more than one cell, such as an insect.

Genetic Material

The molecular instructions that tell an organism how to look and function.

Heredity

The passing of genetic material from parent to offspring.

Inherited Traits

Features of an organism that are spelled out in the DNA received from the parent(s).

DNA (Deoxyribonucleic Acid)

The molecule that encodes genetic information and instructs organisms how to build protein molecules.

Asexual Reproduction

A form of reproduction where offspring form from the genetic information of only one parent.

Sexual Reproduction

A form of reproduction where offspring form from the genetic information of two parents.

Gametes

Sex cells—specifically egg or sperm cells—carrying half of the genetic information.

Growth

The process of making more molecules and/or cells of the type that already exist, causing an organism to gain mass and volume.

Development

The appearance of new and different cells, structures, or abilities pre-coded in existing DNA across an individual's lifetime.

Metabolism

All of the chemical reactions that take place inside an organism to obtain and use energy.

Catabolism (Digestion)

Chemical reactions that break a molecule down into smaller pieces.

Anabolism (Synthesis)

Chemical reactions that build larger molecules from smaller starting molecules.

Homeostasis

An organism's ability to maintain a stable internal environment by adjusting internal conditions to keep them within a safe range.

Interdependence

The principle that all living things rely on other living and nonliving resources to survive.

Biotic vs. Abiotic

Biotic refers to living components (animals, plants, fungi, protists, bacteria), while abiotic refers to non-living components (water, rocks, oxygen, sun).

Evolution

The process over time where newer, more complex organisms arise from older, simpler ones, applying to populations rather than individuals.

Mutation

A change in genetic information or a change in the DNA molecule.

Vertebrate Phylogenetic Trait Tree

A phylogenetic diagram illustrating shared derived traits—such as vertebrae, bony skeleton, four limbs, amniotic egg, hair, and two post-orbital fenestrae—among vertebrate lineages.

Atom

The nonliving, smallest unit of matter.

Molecule

A nonliving structure consisting of two or more atoms joined together.

Organelle

A nonliving, small, specialized structure found inside a cell.

Tissue

A group of cells of the same kind that perform the same function.

Organ

A structure composed of two or more types of tissues that work together to perform a specific function.

Organ System

A group of organs that work together to perform a certain function.

Organism

One individual living thing, ranging from a single cell to a complex entity with numerous organ systems.

Population

Organisms of the same species that live in the same area.

Community

All of the populations of different species that live in the same area.

Ecosystem

All of the living (biotic) and nonliving (abiotic) factors present in an environment.

Biome

A group of similar ecosystems with the same general type of physical environment found across different areas around the world.

Biosphere

The part of Earth where all life exists, including all land, water, and air where living things can be found.

Anthropogenic

Caused or generated by human activity.

Composting

The natural process of breaking down organic matter (like leaves and food scraps) using bacteria and earthworms to recycle it as soil fertilizer.

Ventilation

The physical process of moving gases into and out of the body, distinct from cellular respiration.

Cellular Respiration

The process of releasing energy from food/nutrient molecules and transferring it into the usable cellular energy form of ATP.

Aerobic Cellular Respiration Equation

The metabolic process that uses oxygen to break down glucose into carbon dioxide, water, and energy: $\text{C}_6\text{H}_{12}\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{ATP}$.

Excretion

The biological process of releasing toxic waste molecules from within an organism.

Circulatory (Cardiovascular) System

The body system comprising the heart, blood vessels, and blood that transports oxygen, nutrients, hormones, and cellular waste throughout the body.

Integumentary System

The body system consisting of skin, hair, nails, and sweat and oil glands that acts as a protective barrier, regulates temperature, and detects sensory input.

Endocrine System

The organ system containing the pituitary, thyroid, pancreas, adrenal glands, and gonads that regulates metabolism, growth, mood, and tissue function via hormones.

Urinary (Excretory) System

The body system including the kidneys, ureters, bladder, and urethra that filters metabolic waste from blood, regulates electrolyte balance, and controls blood volume.

Stomata

Microscopic openings on plant leaves that allow gas exchange ($\text{CO}_2$ intake, $\text{O}_2$ and $\text{H}_2\text{O}$ release) and facilitate excretion.

Xylem

Vascular plant tissue specialized for transporting water upward through roots, stems, and shoots.

Phloem

Vascular plant tissue specialized for transporting sugars throughout the plant.

Auxin

A plant hormone that stimulates and increases stem growth.

Flower Reproductive Anatomy

The complete reproductive structure of angiosperms containing male components (stamen: anther, filament, pollen) and female components (pistil: stigma, style, ovary, ovules).

Three Domains of Life

The highest taxonomic ranking consisting of Domain Archaea (prokaryotic archaebacteria), Domain Bacteria (prokaryotic eubacteria), and Domain Eukarya (eukaryotic protists, fungi, plants, and animals).

Kingdom Archaebacteria

A kingdom of unicellular, prokaryotic autotrophs or heterotrophs that typically inhabit extreme environments.

Kingdom Eubacteria

A kingdom of unicellular, prokaryotic autotrophs or heterotrophs that inhabit more familiar temperature and pressure environments.

Kingdom Protista

A diverse kingdom of eukaryotic, unicellular or multicellular organisms that contain membrane-bound organelles and can be autotrophic or heterotrophic.

Kingdom Fungi

A kingdom of eukaryotic, unicellular or multicellular heterotrophs that have chitinous cell walls and do not move on their own.

Kingdom Plantae

A kingdom of eukaryotic, multicellular autotrophs that do not move on their own and have cellulose cell walls.

Kingdom Animalia

A kingdom of eukaryotic, multicellular heterotrophs that can move on their own and lack cell walls.

Binomial Nomenclature

The formal system of naming species using Latin genus and species identifiers, written in italics with the genus capitalized and the species in lowercase.

Autotroph (Producer)

An organism that produces its own food molecules using light energy via photosynthesis.

Heterotroph (Consumer)

An organism that must consume other organisms as an external source of energy and organic food molecules.

Chemotroph

An organism that synthesizes its own food using energy stored in the chemical bonds of harsh inorganic compounds, often found in deep-sea environments.

Prokaryote

A cellular organism lacking a nucleus and separate membrane-bound organelles inside the cell; typically smaller than eukaryotic cells.

Eukaryote

An organism possessing complex cells with separate membrane-bound internal organelles, including a nucleus.

Phylogeny

The classification of organisms based on their shared evolutionary history and genetic relationships, primarily analyzed through DNA similarities and differences.

Taxonomy (Morphology)

The science of describing, naming, and classifying organisms based on observable physical characteristics or structural traits.

Clade

A phylogenetic grouping that consists of a common ancestor and all of its lineal descendants.

Dichotomous Key (Branching Flowchart)

An identification tool dividing choices into paired, mutually exclusive statements based on observable physical features to identify unknown organisms step-by-step.