Reading Check 20.1
Complete this outline while you read section
20.1 of your textbook. You do not need to
answer in complete sentences.
Chapter 20, Section 1: Bacteria
What are prokaryotes
Prokaryotes date back about ______ billion years. They are single-______________________ organisms
that do not have membrane-bound ________________________.
Name each shape of bacteria:
Rod shape
________________________
Sphere shape
________________________
Spiral shape
________________________
Bacterial structure
Bacteria have DNA in a single ________________________ clustered in a mass called a
_____________________. Sometimes they have extra small loops of DNA called _____________________.
Their cell membranes are ________________________ ________________________, and outside the
membrane they have rigid cell ________________________. It is made of a protein-carbohydrate
compound called ________________________.
Gram-________________________ bacteria have a thick layer of peptidoglycan and appear
________________________ after staining, while Gram-________________________ bacteria have a thin
layer of peptidoglycan and appear ________________________ after staining. Gram-negative bacteria
are often more resistance to host defenses and ________________________.
Bacteria propel themselves by rotating their whiplike ________________________.
They can adhere to surface with the help of short, thin tubes called ________________________.
Obtaining energy and nutrients
Bacteria that get energy from sunlight through photosynthesis are ______________________________.
Some prokaryotes, chemoautotrophs, get their energy from ________________________ sources.
Most bacteria are ________________________ and get energy and nutrients from other organisms.
Most of these bacteria ________________________ nutrients from dead organisms, but some are
________________________ or ________________________.
Reproduction and adaptation
Prokaryotes usually reproduce asexually by ________________________ ________________________. Bacteria can form
new genetic combinations by ________________________, ________________________
or ________________________. Some bacteria can survive harsh conditions by forming thick-walled
________________________, which can survive boiling, radiation and acid.
Reading Check 20.2
Complete this outline while you read section 20.2 of your textbook. You do
not need to answer in complete sentences.
Chapter 20, Section 2: Viruses
Is a virus alive
Viruses are not considered living because they cannot
________________________ on their own and they do not grow; instead, they reproducing by
________________________ host cells and are ________________________ to their full size within a cell.
Viral structure
All viruses have a ________________________ acid and a protein coat, or ________________________.
Many viruses have a membrane, or ________________________, surrounding the capsid.
Viruses that infect bacteria are called ___________________________________.
Reproduction
A viral infection begins when a virus’s genetic material enters a ________________________ cell.
The cycle of viral infection that results in the destruction of the host cell is called the
________________________ cycle. Viruses that reproduce only this way are called
________________________.
The cycle in which the viral DNA becomes a part of its host cell’s DNA is called the
________________________ cycle. The virus in this case is called a ________________________, and any
virus whose reproduction includes the lysogenic cycle is called a ________________________ virus.
HIV stands for ________________________________________________________________________ and is the
virus that causes ________________________.
Viroids and prions
A viroid is a single strand of ________________________ with no ________________________. They cause
abnormal development and stunted growth in ________________________.
Prions are misshapen ________________________ that are found in the brain. They can be transmitted
by eating ________________________ contaminated with infected brain tissue.
In the space below, briefly describe the significance of the image above. How does it relate to this section of
the textbook?
Reading Check 20.3
Complete this outline while you read section 20.3 of your textbook. You do not
need to answer in complete sentences.
Chapter 20, Section 3: Bacteria, viruses and humans
Roles of bacteria and viruses
Bacteria produce _____________________________, make _____________________________ available to
other organisms, and help _____________________________ dead organisms. Many form important
_____________________________ relationships.
Bacteria are used in cleaning up _____________________________ spills and in
_____________________________ treatment plants.
Viruses are used in _____________________________ therapy as a way to deliver genetic
material to target cells.
Any disease-causing agent is a _____________________________. Diseases that can spread from
person-to-person are considered _____________________________.
Bacterial diseases
Bacteria can cause disease by producing _____________________________ or by producing
_____________________________ that break down the host’s tissues.
Antibiotic resistance
_____________________________ are chemicals that inhibit the growth of or kill microorganisms.
Many bacteria have developed _____________________________ to these drugs, since
_____________________________ for antibiotic resistance arise naturally and often in bacteria. Many
people fear that bacterial diseases will eventually become _____________________________ to cure.
Viral diseases
Because viruses enter host cells to _____________________________, it is hard to develop a drug
that kills the virus without harming the living _____________________________. A
_____________________________ is a weakened form of a pathogen that prepares the immune system to
recognize and destroy the pathogen.
In the space below, briefly describe the significance of the image above. How does it relate to this section of
the textbook?
Reading Check 21.1 and 21.2
Complete this outline while you read 21.1 and 21.2 of your
textbook, omitting pages 498-499. You do not need to
answer in complete sentences.
Chapter 21, Sections 1 and 2: Characteristics and groups of protists
What are protists?
Protists are _____________________________ organisms that cannot be classified in other kingdoms.
Classifying protists
Answer true or false
_____ The classification of protists is likely to change as we learn more about them.
_____ Studies of DNA, RNA and proteins suggest that protists could be classified in up to 20 different
kingdoms.
Grouping protists
Animal-like protists are called _____________________________, and they ingest other
_____________________________ to obtain energy. They are ______cellular.
Amoebas move about using extensions in their cytoplasm called ____________________________.
Most of a ciliate’s body is covered with _____________________________that they use to
_____________________________ and _____________________________ for food.
All sporozoans are _____________________________ and cause disease.
Plantlike protists are called _____________________________ or _____________________________.
They obtain energy by _____________________________. Diatoms are know for their unique
double _____________________________.
Funguslike protists _____________________________ nutrients from their environment and reproduce
using _____________________________. A plasmodial slime mold is a mass of cytoplasm with many
_____________________________. Some water molds and downy mildews _____________________________
dead organisms, while others are common _____________________________ of fish or plants.
Reading Check 22.1
Complete this outline while you read section 22.1 of your textbook. You
do not need to answer in complete sentences.
Chapter 22, Section 1: Characteristics of fungi
What are fungi
Fungi are made of long, slender ________________________, have cell walls made of
________________________ and are ________________________ organisms that cannot make their
own food. Instead, the break down material in their environment and ________________________ the nutrients.
Structure and function
The threadlike strands in fungi are called ________________________. Many hyphae group together
Form a tangled mass called a ________________________. In some fungi, the hyphae also form
rootlike structures called ________________________.
Fungi that absorb nutrients from dead organisms are called ________________________. Fungi that
absorb nutrients from living hosts are called ________________________.
Reading Check 22.3
Complete this outline while you read section 22.3 of your
textbook. You do not need to answer in complete sentences.
Chapter 22, Section 3: Fungi and humans
Fungi and industry
Name one food you’ve eaten that was made of or with the help of fungi: __________________________
Name two medicines produced from fungi: ____________________________ ___________________________
Fungi and the ecosystem
Fungi play an important ecological role by ____________________________ organic matter and
____________________________ minerals from rocks and soil.
As part of ____________________________, fungi break down rocks and prepare environments for other
organisms.
As part of ____________________________, fungi absorb minerals from the soil and transfer them to
plant ____________________________.
Fungi and disease
____________________________ are fungi that infect the skin and nails. Many fungi produce
dangerous ____________________________.