From Invertebrates to Vertebrates & Biological Classification

Vocabulary flashcards summarizing essential terms from the lecture on vertebrate evolution, animal classification, and life functions.

Amphibian

A cold-blooded vertebrate with moist skin that lays eggs in water and undergoes metamorphosis from an aquatic larva to a land-dwelling adult.

Reptile

A cold-blooded vertebrate with dry, scaly skin that lays hard- or leathery-shelled eggs on land and is well adapted to dry environments.

Metamorphosis

The developmental change in amphibians during which a water-breathing tadpole transforms into an air-breathing adult with lungs and limbs.

Cold-blooded (Ectothermic)

Having a body temperature that varies with the environment; characteristic of fish, amphibians, and reptiles.

Warm-blooded (Endothermic)

Maintaining a constant internal body temperature by producing metabolic heat; characteristic of birds and mammals.

Tadpole

The aquatic, gill-breathing larval stage of a frog or toad, equipped with a tail for swimming.

Gills

Respiratory organs that extract dissolved oxygen from water; present in fish and amphibian larvae.

Lungs

Internal organs used for gas exchange with air; develop in adult amphibians and are present in reptiles, birds, and mammals.

Scales

Waterproof, protective plates covering the skin of reptiles that help reduce water loss.

Eggshell

The hard or leathery outer covering of reptile and bird eggs that shields the embryo and prevents desiccation.

Vertebrate

An animal possessing a backbone; includes fish, amphibians, reptiles, birds, and mammals.

Invertebrate

An animal lacking a backbone, such as insects, worms, jellyfish, and crabs.

Mammal

A warm-blooded vertebrate covered with hair, nourishing young with milk from mammary glands and usually giving birth to live young.

Bird

A warm-blooded vertebrate with feathers, hard-shelled eggs, and a close evolutionary relationship to reptiles.

Feathers

The lightweight, insulating body covering of birds that also enables flight.

Hair (Fur)

The insulating layer of keratin fibers covering mammals, helping regulate body temperature.

Mass Extinction

A geologically rapid event during which a large percentage of Earth’s species die out, such as the one that ended the Age of Reptiles 65 million years ago.

Evolution

The change in the genetic composition of a population over successive generations.

Classification

The scientific practice of grouping organisms based on shared characteristics.

Taxonomy

The branch of biology that names, describes, and classifies organisms into hierarchical categories.

Carolus Linnaeus

The Swedish botanist who developed the hierarchical classification system and binomial nomenclature (genus + species).

Kingdom

The broadest traditional taxonomic rank below domain; e.g., Animalia.

Phylum

A taxonomic rank below kingdom that groups organisms sharing major body-plan features; e.g., Chordata.

Class

A rank below phylum; e.g., Mammalia within Chordata.

Order

A rank below class; e.g., Primates within Mammalia.

Family

A rank below order; e.g., Hominidae within Primates.

Genus

A taxonomic grouping of closely related species; the first part of a scientific name (e.g., Homo).

Species

The most specific taxonomic rank; a group of organisms capable of interbreeding (e.g., sapiens).

Autotroph

An organism that produces its own organic food from inorganic substances, usually using light energy; also called a producer.

Producer

A photosynthetic or chemosynthetic organism that creates its own food and forms the base of a food chain.

Heterotroph

An organism that obtains organic matter by consuming other organisms; also called a consumer.

Consumer

An organism that eats producers or other consumers to gain energy and nutrients.

Photosynthesis

The process by which chlorophyll-containing cells convert carbon dioxide and water into sugars using sunlight, releasing oxygen.

Chlorophyll

The green pigment in plant chloroplasts that captures light energy for photosynthesis.

Organic Matter

Carbon-based molecules derived from living organisms, including carbohydrates, proteins, lipids, and nucleic acids.

Inorganic Matter

Non-living substances lacking carbon-hydrogen bonds, such as minerals, metals, salts, rocks, and water.