Classification of Living Things Study Guide

Flashcards about the classification of living things.

Systematics

The science of naming and grouping organisms.

Taxonomy

The arrangement of organisms into orderly groups based on their similarities.

Binomial Nomenclature

The name given to each species.

Phylogeny

Classification based on descent (tree of life).

Cladogram

A diagram of evolutionary relationships (phylogeny).

Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species

The eight taxonomy levels for classifying living things (largest being domain and smallest being species).

Bacteria

Unicellular and Prokaryotic. Have a cell wall with peptidoglycan for protection. Range from non-harmful organisms living in soil to deadly parasites. Some photosynthesize while others do not; some need oxygen while others are killed by oxygen.

Eukaryota

All eukaryotic; contains 4 Kingdoms.

Archaea

Prokaryotic and Unicellular. Live in some of the most extreme environments on Earth such as volcanic hot springs, brine pools, and black mud devoid of oxygen. Cell walls do not contain peptidoglycan.

Protista

Eukaryotes that are not members of the plant, animal, or fungi kingdoms. Most are unicellular but quite a few are not. The largest protists are brown algae (kelp) containing millions of cells. Now have 6 different clades: Excavata, Chromalveolata, Cercozoa, Rhodophyta, Amoebozoa, Choanozoa

Fungi

Heterotrophic eukaryotes with cell walls that contain chitin. Chitin is a polymer made of modified sugars that provides a hard structure and shape to cells, making fungi similar to plants. Reproduce asexually by releasing spores that travel through air and water. Help organisms maintain homeostasis by breaking down dead organisms and recycling essential nutrients. Example: Mushrooms, mold, & yeast.

Plantae

Depend on sunlight, gas exchange, water, and minerals. All plants are eukaryotes, have cell walls containing cellulose, and carry out photosynthesis using chlorophyll. Examples: Green algae, mosses and bryophytes, ferns, seed plants.

Animalia

Multicellular, heterotrophic, eukaryotic organisms with cells that lack cell walls. Maintain homeostasis by gathering and responding to information, obtaining and distributing oxygen and nutrients, and collecting and eliminating carbon dioxide and other wastes. They must also reproduce. More than 95% of all animals are invertebrates (no backbone) while less than 5% are Chordates (have spinal cord) and vertebrates (have backbone).

Virus

A nonliving particle made of proteins, nucleic acids, and sometimes lipids.

Lytic Infection

A virus enters a bacterial cell, makes copies of itself, and causes the cell to burst (lyse).

Bacteriophage

A kind of virus that infects bacteria

Lysogenic Infection

A host cell is not immediately taken over, but instead the viral nucleic acid is inserted into the host cell’s DNA. DNA is then replicated and allows the virus’s DNA to replicate without harming the host.

Prophage

Bacteriophage DNA that is embedded in the bacterial host’s DNA

Decomposers

Some prokaryotes supply raw materials to the environment by breaking down dead organisms.

Microbiome

Bacteria live in the human body to help us digest food and synthesize vitamins.

Producers

Photosynthetic prokaryotes produce food and biomass and make up the bottom of many food chains.

Nitrogen fixers

The only organisms on our planet that can make nitrogen usable are prokaryotes.

Human Uses (Prokaryotes)

We can use some bacteria to produce foods, remove wastes from water, and synthesize drugs and chemicals for medical use.

Xylem

Brings water up from the root, helps form woody structure of stem.

Phloem

Carries sugars/food downward from leaves.

Mosses and Bryophytes

Have waxy coating and rhizoids that anchor them to the soil and absorb water and nutrients from the environment. They belong to the bryophytes phylum. They are small and found in damp soil because they lack vascular tissue which limits their heights to just a few centimeters. They do not have roots!

Ferns

Contain vascular tissue, do not produce seeds, can survive with little light, and like abundantly wet environments. Reproduce by releasing spores (microscopic cells capable of becoming new organisms) into the environment.

Gymnosperms

Bear their seeds directly on the scales of cones (pine, spruce, and fir trees).

Angiosperms

Bear their seeds within a layer of tissue that protects the seed (flowering plants, food crops).

Seeds

A plant embryo and its food supply encased in a protective covering.

Amphibians

Live in the water as larvae and on land as adults. Reproduce in water, have lungs. (frogs, toads, salamanders).

Birds

Feathers, lightweight bones, scale covered legs, front limb wings. (ostrich, cardinal, eagle, hawk).

Reptiles

Dry, scaly skin, strong limbs, lay eggs, cold blooded. (lizard, snake, tortoise).

Mammals

Mammary glands used to feed young, hair, four chambered heart. (human, dog, cat)

Bony Fish

Fish with a strong, bony skeleton (tuna, bass, trout, other fish).

Cartilaginous Fish

Cartilage skeleton to offer greater body movement control, and better thrust in the water (sharks, rays, skates).

Jawless Fish

Lampreys and hagfish.

Epithelial tissue

Creates protective boundaries and is involved in the diffusion of ions and molecules. (skin, intestines, other organs).

Nervous tissue

Transmits and integrates information through the central and peripheral nervous systems. (Brain, spinal cord, nerves).

Muscular tissue

Contracts to initiate movement in the body. (skeletal, cardiac, smooth).

Connective tissue

Underlies and supports other tissue types. (tendons, cartilage).

Digestive System

Converts food into small molecules that can be used by the cells of the body.

Respiratory System

Picks up oxygen from the air as we inhale and releases carbon dioxide as we exhale.

Circulatory System

Transports oxygen, nutrients, and other substances throughout the body and removes wastes from tissues.

Nervous System

Collects information about the internal and external environment, processes that information, and responds to it.

Skeletal System

Supports the body, protects internal organs, assists in movement, stores minerals, and is a site of blood cell formation.

Muscular System

Produces movement by shortening, or contracting muscles.