Biology 100 - Characteristics, Hierarchy, and Diversity of Life

Vocabulary flashcards covering key terms, definitions, classifications, and comparative characteristics from Biology 100 lecture material.

Arthropods

Excluding the two prokaryotic domains, arthropods (including beetles, flies, wasps, Lepidoptera, and others) constitute the largest group of named animal species at about $59\%$

Beetles

The single largest specific category of named species within animals, making up $22\%$ of total animal species

Domain Bacteria

The most diverse and widespread group of prokaryotes, classified into multiple kingdoms and composed of bacterial cells such as rod-shaped structures

Domain Archaea

A domain of prokaryotes including multiple kingdoms, with members known to live in Earth's extreme environments such as salty lakes and boiling hot springs

Domain Eukarya

The domain comprising all eukaryotic organisms, categorized into Kingdom Plantae, Kingdom Fungi, Kingdom Animalia, and protists

Six-Kingdom Classification System

A classification model dividing life into six kingdoms: Eubacteria, Archaebacteria, Plants, Animals, Fungi, and Protists

Kingdom Plantae

Multicellular eukaryotes that carry out photosynthesis to convert light energy into chemical energy in food, with most species living on land

Kingdom Fungi

Eukaryotic organisms characterized in part by their nutritional mode of absorbing nutrients from outside their bodies

Kingdom Animalia

Multicellular eukaryotes that ingest other organisms for nutrition

Protists

Mostly unicellular eukaryotes and simple multicellular relatives whose evolutionary relationships are actively debated by scientists

Binomial Nomenclature

A rank-based naming system described by Carl Linnaeus where the scientific name consists of a capitalized Genus name and a lowercase Species name, formatted entirely in italics (e.g., Vulpes vulpes or Homo sapiens)

Taxonomic Hierarchy

The nested organizational ranks used to classify living organisms from broadest to most specific: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Cell

The smallest functional unit that exhibits all eight features of life, enclosed by a cell membrane (phospholipid bilayer) separating the internal living environment from the non-living outside

Tissue

A group of specialized cells that work together to perform a specific function

Organ

A distinct biological structure typically made up of multiple tissue types that carries out a specific function

Organ System

A collection of organs that work together to carry out specific functions within an organism

Organism

An individual living entity, either single-celled or multicellular, that carries out all eight characteristics of life

Homeostasis

One of the eight characteristics of life, defined as the maintenance of stable internal conditions

Metabolism

One of the eight characteristics of life, referring to energy management and chemical processing within an organism

Regulation

One of the eight characteristics of life, defined as the coordination of internal conditions

Evolution

One of the eight characteristics of life, defined as change over time via natural selection and heredity

Universal Cellular Features

The four features shared by all prokaryotic and eukaryotic cells: cell membrane, DNA, cytoplasm, and ribosomes

DORA

An acronym for comparing prokaryotes and eukaryotes based on DNA, Organelles, Reproduction, and Average Size

Prokaryotic Cell Characteristics

Cells with naked circular DNA (usually no introns), single haploid chromosome, no nucleus, no membrane-bound organelles, $70\text{S}$ ribosomes, reproduction via binary fission, and an average size of $\sim 1\text{--}5\,\mu\text{m}$

Eukaryotic Cell Characteristics

Cells with linear DNA bound to protein (usually with introns), paired diploid or polyploid chromosomes, a nucleus, membrane-bound organelles, $80\text{S}$ ribosomes, reproduction via mitosis and meiosis, and an average size of $\sim 10\text{--}100\,\mu\text{m}$

Relative Sizes of Biological Entities

A comparison of biological sizes ranging from non-living Prions ($5\,\text{nm}$) and Viruses ($10\text{--}300\,\text{nm}$) to Archaebacteria ($0.1\text{--}15\,\mu\text{m}$), Eubacteria ($0.2\text{--}50\,\mu\text{m}$), and Eukaryotic cells ($10\text{--}100\,\mu\text{m}$)

Prion

A non-living entity consisting of misfolded proteins measuring approximately $5\,\text{nm}$ in size

Virus

A non-living biological entity ranging from $10\text{--}300\,\text{nm}$ in size that is not considered a living organism or cell

Abiotic and Biotic Ecological Levels

Ecological categories above community level (Ecosystem, Biome, Biosphere) that are not defined as pure units of life because they contain both living (biotic) and non-living (abiotic) components