Unit 1: Characteristics and Classification of Living Organisms

This set of flashcards covers vocabulary and key concepts from Biology Unit 1, including the characteristics of life, classification methods, kingdom features, and plant/animal groupings.

Biology

The study of organisms.

Organism

A complete living thing, such as a human, a platypus, a bacterium, or a mango tree.

Movement

An action by an organism or part of an organism causing a change of position or place.

Respiration

The chemical reactions in cells that break down nutrient molecules and release energy for metabolism.

Sensitivity

The ability to detect and respond to changes in the internal or external environment.

Growth

A permanent increase in size and dry mass.

Reproduction

The processes that make more of the same kind of organism.

Excretion

The removal of the waste products of metabolism and substances in excess of requirements.

Nutrition

The taking in of materials for energy, growth, and development.

Classification of Organisms

The grouping of organisms based on shared features.

Species

A group of organisms that can reproduce to produce fertile offspring.

Fertile

A term meaning that offspring are also able to reproduce when they are adult.

Binomial System

A system that assigns each species a two-part Latin name indicating its genus and species (e.g., Homo sapiens).

Dichotomous Keys

Tools for identifying organisms based on a series of choices that lead to the correct name.

Morphology

A method of classification based on looking at the overall form and shape of the organism.

Anatomy

A method of classification based on the detailed body structure as determined by dissection.

Kingdom Plants

Multicellular organisms with cell walls made of cellulose and chloroplasts for photosynthesis.

Kingdom Animals

Multicellular organisms with no cell walls that feed on organic material and move actively.

Kingdom Fungi

Organisms with cell walls made of chitin (not cellulose) that lack chlorophyll and obtain nutrients through saprophytic or parasitic means.

Kingdom Protoctists

Organisms that are often unicellular, have a nucleus, and may or may not have a cell wall and chloroplasts.

Kingdom Prokaryotes

Unicellular organisms with no nucleus, having cell walls made of peptidoglycan and a circular loop of DNA free in the cytoplasm.

Hyphae

Microscopic threads that make up the main body of most fungi.

Mycelium

A structure formed by several hyphae together.

Spores

Tiny groups of cells with a tough, protective outer covering used by fungi for reproduction and dispersal.

Vertebrates

Animals that have a backbone or spinal column.

Invertebrates

Animals that do not have a backbone.

Arthropoda

A phylum of invertebrates grouped together based on shared features such as jointed limbs, segmented bodies, and an exoskeleton.

Endothermic

The ability to maintain a constant internal body temperature.

Pinnae

The external part of the ears, a characteristic of mammals.

Myriapods

Arthropods with bodies consisting of many segments, each containing at least one pair of jointed legs and one pair of antennae.

Insects

Arthropods with a three-part body (head, thorax, abdomen), three pairs of jointed legs, two pairs of wings, and one pair of antennae.

Arachnids

Arthropods with a two-part body (cephalothorax, abdomen), four pairs of jointed legs, and no antennae.

Crustaceans

Arthropods with more than four pairs of jointed legs, a chalky exoskeleton, and two pairs of antennae.

Angiosperms

Flowering plants that produce seeds from fertilized ovules in ovaries within flowers.

Ferns

Plants that lack flowers and seeds, instead reproducing asexually by spores formed on the underside of fronds.

Cotyledon

A seed leaf found in the seeds of flowering plants.

Monocots

Flowering plants with one seed leaf, parallel leaf veins, flower parts in multiples of three, and scattered vascular bundles.

Dicots

Flowering plants with two seed leaves, net-like leaf veins, flower parts in multiples of four or five, and vascular bundles arranged in a ring.

Virus

A non-living entity consisting of genetic material (RNA or DNA) inside a protein coat that requires a living cell to replicate.