Reading Check 18.1
Complete this outline while you read section 18.1 of your textbook. You do not need to answer in complete sentences.
Chapter 18, Section 1: Classification
The need for systems
About ______ million species have been named by scientists, be we think that ____________________ more still have not yet been discovered.
________________________ is the practice of naming and classifying organisms. The general name for any category into which biologists organize living things is a ________________________.
Scientific nomenclature
The Swedish biologist ________________________ invented the system of ________________________ nomenclature during the 1750s. He used the ________________________ name followed by a single descriptive word for each species. Today, this two-word name for a species is known as its
________________________ name.
Linnaean system
In the modern system for organizing living things, similar species are grouped into the same
________________________, similar genera are grouped into the same ________________________, and so on.
The broadest, most general, taxon is the ________________________. There are only three of these.
The next level of organization is the ________________________. There are six of these within three domains.
Kingdoms are broken into ________________________. Many of these exist within in kingdom.
A ________________________ is a subgroup within a phylum.
An ________________________ is a subgroup within a class.

In the space below, briefly describe the significance of the image above. How does it relate to this section of the textbook?

Reading Check 18.3
Complete this outline while you read section 18.3 of your textbook. You do not need to answer in complete sentences.
Chapter 18, Section 3: Kingdoms and domains
Updating classification systems
For a long time, scientists only recognize the kingdoms ________________________ and
________________________.
Kingdom ________________________ was created for prokaryotes, until scientists realized that there were really two very different groups of prokaryotes. So, Kingdom ________________________ was split into kingdoms ________________________ and ________________________.
The three-domain system
Today, scientists recognize _____ domains and _____ kingdoms.
In order to assign living organisms to various taxa, scientists use characteristics including…
 cell type , whether the cells are ________________________ or ________________________
 cell walls
 body type, whether the organism is ________________________ or ________________________
 nutrition, whether the organism is an ________________________ or ________________________
 and genetics.
Because domain Bacteria has just one kingdom, it is equivalent to Kingdom
________________________.
Because domain Archaea has just one kingdom, it is equivalent to Kingdom
________________________. Archaebacteria are placed into a different domain from Bacteria because they have different cell ________________________ and ________________________ and unique
________________________ systems. Many archaea are called ________________________ because they live in extreme environments.
Domain Eukarya includes Kingdoms ________________________, ________________________,

________________________ and ________________________.
Almost all plants are ________________________, meaning they produce their own food. Their cell walls are made of ________________________.
Animals are ________________________ heterotrophs. There cells lack rigid ________________________ .
Fungi are ________________________, meaning that they do not produce their own food. There cell walls are made of ________________________.
Kingdom ________________________ is a diverse group, since they did not descend from a common
________________________.

Reading Check 4.1
Complete this outline while you read section 4.1 of your textbook, omitting pages 81-84. You do not need to answer in complete sentences.
Chapter 4, Section 1: What is an ecosystem?
Ecosystems
A group of many species living in the same place and interacting with each other is called a
_____________________________. That group of many species, along with their physical environment, make up an _____________________________. _____________________________ factors are the living factors in an ecosystem. Physical, nonliving factors are called _____________________________. A
_____________________________ is the place where an organism lives.
The variety of organisms in a given area is called _____________________________. When this decreases in an ecosystem, we say that the ecosystem is not _____________________________.
In the space below, briefly describe the significance of the image above. How does it relate to this section of the textbook?

Reading Check 4.2
Complete this outline while you read 4.2 of your textbook. You do not need to answer in complete sentences.
Chapter 4, Section 2: Energy flow in ecosystems
Trophic levels
The primary source of energy for an ecosystem is the _________________.
Photosynthetic organisms who can change the sun’s energy into usable chemical energy are called
_____________________________. _____________________________ eat other organisms, instead of producing their own food. _____________________________, a group that includes bacteria and fungi, break down the dead remains of animals. Each step in this transfer of energy is called a
_____________________________ level.
In ecosystems, energy flows from one trophic level to the next, forming a
________________ ___________________. The first trophic level is made of _____________________________, including plants, algae and some bacteria. The second trophic level is made up of
____________________________, which eat producers. The third tropic level is made up of
_____________________________, which are animals that eat other animals. Other carnivores, which eat other carnivores, are on the _____________________________ trophic level.
_____________________________ are any animals that are both herbivores and carnivores.
In most ecosystems, energy flow is much more complicated than a simple food chain; thus, a more interconnected group of food chains, called a food _____________________________, is often more useful.
Loss of energy
When an animal eats a certain amount of food, only about ______% of that energy becomes a part of that animal, and is eventually passed on to the next trophic level when the animal is eaten.

The remaining _____% of the food energy eaten by that animal is used by the animal for its daily activities— running, eating, etc.
In an energy _____________________________, we can see that _____________________________ form the base, and the lowest trophic level has the most _____________________________ in the pyramid.

Reading Check 4.3
Complete this outline while you read section 4.3 of your textbook, omitting p.
93. You do not need to answer in complete sentences.
Chapter 4, Section 3: Cycling of matter
The five most important substances for life are oxygen, phosphorus,
_____________________________, _____________________________ and _____________________________. In order to support life, an ecosystem must be able to ________________________ these kinds of matter.
Water cycle
Water vapor ________________________ in the sky and falls to Earth’s surface as
________________________. Some of this water ________________________ into the soil and becomes groundwater.
Other water runs across the surface of Earth into rivers, lakes, and oceans. Then, the water is heated by the sun and reenters the atmosphere by ________________________. Water also evaporates from trees and plants in a process called ________________________.
Carbon and oxygen cycles
Plants use the carbon dioxide, CO
2
, in air to build organic molecules during the process of
________________________. During photosynthesis, ________________________ is released into the surroundings.
Many organisms, such as animals, use this oxygen to help break down organic molecules, which releases energy and CO2. This process of exchanging oxygen and CO2 between organisms and their surroundings is called ________________________..Carbon is also released into the atmosphere in the process of ________________________, or burning. This occurs when humans burn fossil ________________________ to generate electricity and to power vehicles.
Nitrogen cycle

The atmosphere is about _____% nitrogen gas, N
2
, but this is not a form of nitrogen that organisms can use. They rely on a few bacteria that can split nitrogen gas to form ________________________,
NH
3
. This process is called nitrogen ________________________. Plants take up nitrogen from the soil in a process called ________________________. When an animal eats a plant, the nitrogen compounds from the plant becomes part of the animal’s body, until the animal either dies or excretes it.
Bacteria return that nitrogen to the soil during ________________________. Eventually, that nitrogen is returned to the atmosphere as nitrogen gas.

Reading Check 5.2
Complete this outline while you read section 5.2 of your textbook. You do not need to answer in complete sentences.
Chapter 5, Section 2: Interactions in communities
Predator-prey interactions
____________________________ is the act of one organism killing another for food. Species involved in predator-prey relationships often develop ____________________________ in response to one another. This back-and-forth evolutionary adjustment is called ____________________________.
In ____________________________, one organism, the parasite, feeds on another organism called the ____________________________. The host is usually harmed but not ____________________________, (so this is not technically a predator-prey interaction).
____________________________ are animals that feed on plants; unlike predators, they rarely
____________________________ the plant.
Other interactions
____________________________ is a relationship in which two species live in close association with each other.
A symbiotic relationship in which both species benefit is called ____________________________.
A symbiotic relationship in which one benefits and the other is neither helped nor harmed is
Called ____________________________.

In the space below, briefly describe the significance of the image above. How does it relate to this section of the textbook?