Taxonomy Lecture Notes
Do all plants and animals have the same genes?
No, but some organisms are closely related. Grouping organisms into__________________
helps scientists find information about living things more easily. For instance, if you know that a
cobra is a snake, you know that it has scaly skin and no legs. Biologists group organisms into
categories based on how closely related the organisms are. Classifying living things in this way
helps biologists study how organisms have changed over time.
What are these categories?
First of all, living things are classified into large groups called_____________________. Each
kingdom is divided into smaller groups, these smaller groups are divided into even smaller
groups, and so on. These groups from largest to smallest, are _______________,
_____________, ______________, __________________, _________________,
___________________, and __________________.
How many kingdoms are there? And what’s in them?
Today the most widely used classification system contains __________ kingdoms. This system
has changed over the years to include new information. The following list shows the names and
major characteristics of the six kingdoms.
● _________________________: This kingdom includes unicellular (one celled)
prokaryotes that often live in extreme environments. Some archaebacteria are
_____________________ (make their own food), and some are ___________________
(cannot make their own food). Examples of archaebacteria include the bacteria that live
in hot springs.
● ___________________: This kingdom also includes unicellular prokaryotes that may
or may not make their own food. However, most eubacteria do not live in extreme
environments. Examples of eubacteria include the bacteria that cause strep throat.
● _________________________: This kingdom includes mostly one-celled eukaryotes.
However, there are a few protists that are multicellular. Protists may be autotrophs or
heterotrophs. Examples of protists include amoebas, slime molds, and algae.
● _________________: Most fungi are multicellular eukaryotes, although there are a few
unicellular fungi. All fungi are heterotrophs with cell walls. Examples of fungi include
mushrooms,
yeasts, and molds.
● ____________________: Plants are multicellular eukaryotes. They have cell walls and
specialized tissues and organs. Plants can make their own food, so they are autotrophs.
Examples of plants include mosses, ferns, trees, and grasses.
● _____________________: Like plants, animals are also multicellular eukaryotes with
specialized tissues and organs. However, animals are heterotrophs and lack cell walls.
Examples of animals include worms, insects, fish, birds, reptiles, and mammals, including
humans.
How do scientists know which group to place organisms in?
Scientists classify organisms based on a variety of _________________________, including
genetic makeup, body chemistry, physical structures, and more. Let’s use the
__________________ of materials as an example of one characteristic that scientists use to
classify some types of organisms. All living things must be able to transport materials such as
_________________ and _______________ within their bodies. Organisms that are closely
related have similar structures to accomplish transport. Archaebacteria, eubacteria, and most
protists are one-celled organisms. Because they are so small, they do not need to transport
materials great distances, and they do not have well-developed transport systems.
Some protists, however, have organelles called _____________________
___________________. These __________________ collect excess water and pump it out of
the cell.
Even though many fungi are ______________________, they also lack circulatory systems.
Instead, materials within fungi are transported directly from cell to cell. By contrast, many plants
have specialized transporting tissues called _______________ and ___________________.
Xylem transports _______________ and ________________ throughout a plant, and phloem
transports _______________ from one part of a plant to another. We’ll talk more about this in
Objective 3.
Animals have the most-developed transport systems of all. In animals the transport system is
called the ________________________ _________________. The ___________________
system of many animals includes a heart that pumps blood throughout the body. The blood
travels in vessels and carries nutrients, oxygen, and waste products such as carbon dioxide.
Fish have a __________-chambered heart, amphibians have a _________________-chambered
heart, and birds and mammals have a _______________-chambered heart. Fish have a
circulatory system with a single ____________.
Amphibians, birds, and mammals have a circulatory system with ____________ loops, one to the
___________ and one to the _______________.