BIOL 127 - Chapter 8 Smartbook

In the acute phase of HIV infection, the immune system combats the loss of CD4+ T cells by producing as many as two billion new T cells a day. This is what model for T cell loss?

"kitchen sink"

Approximately how many people died from HIV/AIDS in 2019?

690,000

What is a bacterial plasmid?

A small, circular piece of DNA separate from the bacterial chromosome

The function of bacterial fimbriae relates to _____.

Adhering to surfaces

It is generally accepted that HIV originated in the continent of _____.

Africa

Gonorrhea, strep throat, tuberculosis, and syphilis are human diseases caused by _____.

Bacteria

Tuberculosis is caused by what type of microbe?

Bacterium

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

CD4

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

Clostridium tetani

XDR TB stands for extensively ___-resistant tuberculosis.

Drug

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

Following exposure to HIV-infected cells, the first cells to be infected in a new host are usually _____.

Macrophages

The function of bacterial flagella relates to _____.

Motility

Malaria is caused by protists of the genus _____.

Plasmodium

Of these four species of protists that cause malaria in humans, which one causes the most disease and death?

Plasmodium falciparum

The key factor that determines the distribution of malaria throughout the world is the _____.

Presence of the masquito vector

Infectious particles made of only proteins are called ____.

Prions

Which is a common treatment for malaria?

Quinine

How is HIV classified?

Retrovirus

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

True

True or false: If an HIV antibody test is negative, there is a chance the person can still transmit HIV.

True

Currently the number one cause of death in AIDS patients worldwide is _____.

Tuberculosis

The nucleic acid packed inside an HIV particle consists of _____.

Two molecules of single-stranded RNA

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

Approximately what proportion of the world's human population has been exposed to TB?

one-third

Although the virus probably existed much earlier, the first direct evidence of HIV infection in humans is from blood samples that were obtained from patients in the _____.

1950s

How many major types of HIV have been discovered?

2

As of 2019, about how many people were estimated to be living with HIV infection worldwide?

38 Million

The incubation period of tuberculosis (from infection to appearance of illness) is relatively long, ranging from _____.

4 to 12 weeks

All of the following that are true about a retrovirus.

A retrovirus uses reverse transcription; It has RNA

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

Acquired

HIV most likely originated on which continent?

Africa

The bacterium that causes tuberculosis is mainly spread by _____.

Airborne droplets

Because of the associated barriers to entry, which type of sexual behavior involves the most risk of transmission of HIV?

Anal intercourse

Bacterial cell walls contain a unique amino disaccharide, the synthesis of which is inhibited by drugs like penicillin. What type of drug is penicillin?

Antibiotic

The characteristics of MRSA, a type of Staph infection, that make it particularly dangerous.

Antibiotic Resistance

There are generally two types of tests for HIV; those that detect the immune system's response are ______ tests.

Antibody

Which type of organism is a single-celled prokaryote?

Bacterium

The genetic material of HIV is protected by 3 protein coats: the nucleocapsid, matrix, and ___ .

Capsid

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

Capsid

The cell wall of some bacteria is surrounded by a structure with a thick, gelatinous consistency, called a , ____ that may help the bacteria to stick to surfaces.

Capsule

Which of these features is unique to the retroviruses?

Convert viral RNA into DNA

The three of these signs or symptoms that are common in active tuberculosis.

Coughing up blood; Chest pains; Weight loss

The function of a bacterial pilus relates to _____.

DNA Transfer

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

Decreases; Increases

Prion diseases are most commonly transmitted by _____.

Eating infected brain or nerve tissues

Tuberculosis is likely to be transmitted to caregivers and on long plane flights because _____.

Exhaled bacteria can be infectious in the air for hours

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

False

True or false: Similar to cells, all viruses have DNA as their genetic material.

False

True or false: The first documented case of AIDS caused by HIV infection in the United States was in a homosexual man who died in the early 1980s.

False

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

False

True or false: Malaria parasites are transmitted by male mosquitoes.

False; only Female

Common signs or symptoms of influenza include which of these?

Fever; Cough; Head and body aches

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

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

What form of influenza currently has the most potential to create a pandemic?

H5N1

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

Helper T cells

Infections with MRSA are particularly common in which three of these groups?

Hospitalized patients; Athletes who share equipment; & Nursing home residents.

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

Immune

Which body system fails as a result of the Ebola virus?

Immune system

Most people infected with Mycobacterium tuberculosis have bacteria within tubercles, but they lack symptoms and are not contagious. This condition is known as ____ tuberculosis.

Latent

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

Load

Insecticide treated mosquito nets reduce the risk of transmitting which of these diseases?

Malaria

MDR TB is (more/less) ____ common than XDR TB. Eastern Europe and Southeast Asia have the highest rates of (MDR/XDR) TB ____.

More; MDR

The vector of malaria is _____.

Mosquito

Tuberculosis is caused by a bacterial species of the genus _____.

Mycobacterium

During the first three weeks of an HIV infection, the HIV antibody test is typically

Negative

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

Opportunistic

An epidemic that is confined to a local area is called a(n) ____ , whereas a global epidemic is called a(n) ____ .

Outbreak; Pandemic

The general term for a bacterium, virus, or other microbe that causes disease is a(n) _____.

Pathogen

Bacterial pili can be related to the development of antibiotic resistance because _____.

Pili can be used to transfer genes that code for resistance mechanisms

Genes coding for antibiotic resistance in bacteria are often located on small, circular pieces of DNA called ____.

Plasmids

Creutzfeldt-Jakob disease, mad cow disease, and scrapie in sheep are diseases caused by infectious particles called___.

Prions

Which statement best summarizes the "kitchen sink" model of CD4 T cell loss during the acute phase of HIV infection?

Production of T cells is the faucet; loss of T cells is the drain

The most crucial factor in preventing transmission of MRSA is _____.

Proper hand-washing

Prions are infectious particles made of _____.

Protein only

Once HIV RNA is reverse transcribed into HIV DNA and integrated into the DNA of a host cells, the viral DNA is called a(n) ___ .

Provirus

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

Receptor

What two types of human cells are infected by malaria parasites of the genus Plasmodium?

Red blood cells; Liver cells

A disease that comes back after a significant decline in incidence is considered to be _____.

Reemerging

Although prion proteins are present in normal tissues, the disease-causing forms are thought to lose their normal function and to cause disease by _____.

Refolding normal prion proteins into a new shape.

The process of HIV uncoating specifically refers to _____.

Release of HIV RNA and viral proteins into a host cell

A bacterium that is unaffected by an antibiotic drug is said to be a ____ bacterium.

Resistant

MRSA stands for methicillin-___ Staphylococcus aureus.

Resistnat

A emerging virus that was first reported in Saudi Arabia in 2012 is MERS, or Middle East ____ syndrome.

Respiratory

An emerging virus that was first reported in Saudi Arabia in 2012 is MERS, or Middle East ____ syndrome.

Respiratory

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

Retroviruses

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

Reverse

Malaria is most common in which part of the world?

Sub-Saharan Africa

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

Tetanus

Antibiotics in the penicillin class kill bacteria by inhibiting production of _____.

The cell wall

What is the major factor that determines whether a person infected with Mycobacterium tuberculosis remains in the latent stage, or develops active TB?

The effectiveness of the immune response

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

Parasites of the genus Plasmodium, which cause malaria, are transmitted _____.

Through the bite of a mosquito

True or false: Patients with latent tuberculosis often do not feel sick and are non-infectious.

True

A characteristic feature of tuberculosis is the formation of small, hard nodules called ___ in the lungs.

Tubercles

A living organism, such as a mosquito, that transfers a pathogen from one host to another is a(n) ____.

Vector

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

Virus

The common cold, flu, measles, polio, genital warts, and AIDS are human diseases caused by

Viruses

The phagocytic cells that prevent an infection due to a pathogen that has penetrated a barrier are what type of cells?

White blood cells

How soon after HIV infection can an at-home test detect its presence?

Within a matter of weeks

Bacteria reproduce by a process called ___ fission.

binary

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

What type of disease does Ebola cause?

hemorrhagic fever

A pathogen is a microbe that _____.

is a disease causing agent

All bacteria are ______ that ______ a nucleus.

prokaryotes; lack