Chapter 8

Arrange the steps in a typical virus replication cycle according to the order in which the occur, with the first step at the top.

1. virus interacts with receptor on host cell surface 2. Viral DNA or RNA enters cell 3. viral proteins are translated 4. viral components, including the capsid are assembled

pili

Bacteria can transfer DNA between cells using an elongated, hollow appendage called a

Protease

Breaks down viral polypeptides into functional proteins

Reverse transcriptase

Converts viral RNA into viral DNA

Attachment

HIV gp120 binds to CD4 receptor.

Integrase

Inserts viral DNA into host cell DNA

two essential components that all viruses have.

Outer capsid Inner core with nucleic acid

all characteristics of viruses.

Parasites of cells Acellular

How is HIV classified?

Retrovirus

Which disease is due to a bacterial toxin that prevents muscle relaxation?

Tetanus

Reverse transcription

Viral RNA genome is converted into DNA.

budding

Virus exits host cell.

The human immunodeficiency virus causes AIDS, which stands for immunodeficiency syndrome.

acquired

The function of bacterial fimbriae relates to

adhering to surfaces

HAART stands for highly active therapy.

antiretroviral

During category B HIV infection the CD4 T-cell count ________ while the viral load ________.

decreases; increases

Motile bacteria usually have one or more long, thin cellular appendages called

flagella

During the first few weeks of an HIV-1B infection, the virus typically

generates a high viral load.

A pathogen is a microbe that

is a disease causing agent

The enzyme inside the HIV matrix that catalyzes the conversion of viral RNA into viral DNA is transcriptase.

reverse

The HIV provirus is defined as Blank

viral DNA inserted into the host genome

Arrange these events of the reproductive cycle of HIV life cycle in chronological order, with the earliest event at the top.

1.attachment 2.fusion/entry 3.reverse transcription 4.integration 5. biosynthesis/assembly 6. budding

Select all of the following that are true about a retrovirus.

A retrovirus uses reverse transcription. It has RNA.

During the attachment phase of HIV replication, the gp120 spike protein of HIV attaches to what protein on a host cell surface?

CD4

biosynthesis

Cell produces viral RNA, and viral proteins.

Which bacterial species produces a toxin that can cause all the muscles of the body to contract?

Clostridium tetani

Which of these features is unique to the retroviruses?

Convert viral RNA into DNA

True or false: Under most circumstances, kissing can transmit HIV.

HIV is not transmitted by saliva, but if there are oral lacerations on the carrier, they can transmit HIV by kissing

True or false: One benefit of highly active antiretroviral therapy (HAART) is that it can eliminate all HIV proviruses.

HIV proviruses are integrated into host cellular DNA, where they are protected from antiviral therapy. false

Select two cell types infected by HIV.

Helper T cells Macrophages

Select ways in which HIV can be transmitted.

Ingestion of breast milk Injection with contaminated needle Vaginal intercourse Rectal intercourse

Match each enzyme encoded by the HIV genome with the description of its action.

Integrase matches Inserts viral DNA into host cell DNA Protease matches Breaks down viral polypeptides into functional proteins Reverse transcriptase matches Converts viral RNA into viral DNA

Which of the following are characteristic of category C HIV infection?

Kaposi's sarcoma Infection with Mycobacterium tuberculosis

assembly

New viral particles are made.

HIV belongs to which group of viruses, all of which use reverse transcriptase to convert viral RNA into DNA?

Retroviruses

integration

Viral DNA inserts into host cell genome.

Fusion/entry

Viral envelope fuses with host cell, HIV RNA is released.

Clostridium tetani

Which bacterial species produces a toxin that can cause all the muscles of the body to contract?

virus

Which type of microbe is a parasite of cells, is acellular, and bridges the gap between what is considered to be living and nonliving?

What type of drug is penicillin?

antibotic

Bacteria reproduce by a process called what fission.

binary

An HIV-infected person who has a CD4 T-cell count less than 200 cells/mm3 and has developed at least one of the AIDS-defining opportunistic infections is classified in which CDC category of HIV infection?

c

The two essential components shared by all viruses are a core of nucleic acids surrounded by an outer blank formed from protein.

capsid

Antibiotics in the penicillin class kill bacteria by inhibiting production of

cell wall

Many bacteria can use hollow appendages called pili to transfer DNA between cells in a process called

conjugation

Some bacteria have stiff fibers on their outer surface called that help them adhere to host cells.

fimbriae

Bacteria reproduce through a process called binary

fission

pathogen

general term for a bacterium, virus, or other microbe that causes disease

During the attachment phase of HIV replication, what specific HIV protein attaches to CD4 on the surface of a helper T cell or a macrophage?

gp120

During a category A HIV infection, the number of helper T cells is ____ the minimum number needed for the immune system to function normally.

greater than

The immunodeficiency associated with HIV infection is mainly due to a decline in the number of

helper T cells

An opportunistic infection is one that takes advantage of a weakened system.

immune

The number of HIV particles in a person's blood is called the viral .

load

The function of bacterial flagella relates to

motility

An infection that develops because an individual has a weakened immune system is called Blank

opportunistic

The general term for a bacterium, virus, or other microbe that causes disease is a

pathogen

Which of the following are signs or symptoms of a person with a category B HIV infection?

persistent or recurrent fever persistent fatigue, cough, and/or diarrhea

Viruses infect a specific type of host cell because they bind to what type of molecule on the host cell surface?

receptor

The process of HIV uncoating specifically refers to

release of HIV RNA and viral proteins into a host cell

bacterium

single-celled prokaryote

Acquired immunodeficiency syndrome is caused by

the human immunodeficiency virus

The major factor that determines which types of cells can be infected by HIV is

the specific surface receptors present

True or false: A person with acute phase (category A) HIV infection typically is asymptomatic.

true

After HIV fuses with a host cell membrane, the capsid and protein coats are removed in a process specifically called

uncoating

Which type of microbe is a parasite of cells, is acellular, and bridges the gap between what is considered to be living and nonliving?

virus