Which of the following is a major function of macrophages?
attacking cancerous cells
secreting antibodies
attacking cells infected by a virus
engulfing bacteria by phagocytosis
secreting cytokines to simulate the proliferation of other lymphocytes
Which of the following is a major function of cytotoxic T lymphocytes?
Which of the following is a major function of B lymphocytes?
Antibiotics (such as penicillin) are produced naturally by
certain fungi and bacteria
macrophages
B lymphocytes
viruses
T lymphocytes
An antibiotic (such as penicillin) works by
destroying all antigens present in the body
killing viruses only
killing both bacteria and viruses
killing bacteria only
neutralizing bacterial toxins
The main function of an antibody is to
initiate the destruction of bacteria
stimulate the proliferation of lymphocytes
destroy cells infected by a virus
destroy cancerous cells
engulf bacteria by phagocytosis
Which of the following is a true statement about bacteria?
bacteria are not affected by antibiotics
bacteria cause disease by reproducing inside of the body's cells
all bacteria that enter the human body are harmful
bacteria are harmful to the environment
bacteria cause disease by secreting toxins
there are many beneficial bacteria that live within the human body
Bacteria are not affected by antibiotics.
Bacteria cause disease by reproducing inside of the body's cells.
All bacteria that enter the body are harmful.
Bacteria play an essential role in nature's chemical recycling.
Most bacteria are harmful to the environment.
Which of the following is a true statement about plasmids?
They are found in bacteria, viruses and fungi.
They contain more genes than the bacterial chromosome.
They enable some bacteria to become pathogens.
They prevent bacteria from mating with one another.
They are short, straight segments of DNA.
They enable some bacteria to resist antibiotics.
They enable some bacteria to utilize rare nutrients.
Mad cow disease is caused by
a virus that infects helper T lymphocytes.
a virus that infects neurons.
a prion that infects brain tissue.
a bacteria that weakens the immune system.
a bacteria that infects brain tissue.
AIDS is a disease that is caused by
a prion that destroys lymphocytes.
a viroid.
a virus that infects B lymphocytes.
a bacteria that kills macrophages.
A viroid is a
piece of RNA that infects plant cells.
virus that infects helper T lymphocytes.
virus that infects bacteria.
type of bacteria that lives in the intestine.
protein that infects brain tissue.
Which of the following are found in a virus?
nucleic acids
all of these
enzymes
attachment structures such as spikes
capsid coat
Viruses are not true cells because
They lack nucleic acids.
They cannot reproduce unless inside of a host cell.
They are slightly smaller than prokaryotic cells.
They consist of one small piece of protein.
They cause human disease.
Which of the following happens when a RNAcontaining virus infects a cell?
The host cell transcribes the viral DNA and produces new viral components.
The virus may cause Mad Cow disease.
The host cell uses the viral enzyme "reverse transcriptase" to make a copy of viral DNA.
The virus becomes a symbiont of the cell.
The virus provides ATP for the cell.
Which of the following happens when a DNAcontaining virus infects a cell?
Which of the following best describes the enzyme "reverse transcriptase"?
It is an enzyme that RNA-viruses use to make the host cell copy DNA from viral RNA.
It is a human enzyme used in metabolism.
It is a bacterial enzyme used in transcription of bacterial DNA.
It is an enzyme that DNA viruses use to make the host cell copy RNA from viral DNA.
It is an enzyme that host cells use to destroy viruses.
What is the purpose of restriction enzymes in nature?
They are used by fungi to kill bacteria.
They have no purpose in nature.
They are used by bacteria to prevent infection by viruses.
They are used by viruses to infect bacteria.
They are part of the human immune system.
How do biologists use restriction enzymes?
to cut DNA into thousands of 4nucleotide fragments
to cut DNA at specific nucleotide sequences to produce DNA fragments
none of these
to restrict the replication of DNA within cells
to cut RNA into several large fragments
What is the source of restriction enzymes?
They are manufactured in the laboratory.
They are obtained from fungi.
They are obtained from the human blood stream.
They are obtained from bacteria.
They are obtained from viruses.
One reason for using restriction enzyme technology is
to treat human disease
to identify the location of specific genes
to predict the function of specific genes
to begin the process of DNA fingerprinting
to identify the number of proteins in a cell
In the RFLP method of DNA fingerprinting, how are DNA fragments separated?
by paper chromatography
by centrifugation
by gel electrophoresis
by treatment with several different enzymes
In a DNA fingerprint using the RFLP method, what forms the bands of the "fingerprint"?
Each band is a single DNA fragment of a different length.
Each band is a group of DNA fragments of a different size.
Each band is DNA from a different cell type.
Each band is a RNA fragment with a different nucleotide sequence.
Microarrays are used to
determine which genes have been expressed by a given cell type
determine the nucleotide sequence of genes
determine whether mRNAs from a cell have been translated
determine which genes are present in the DNA of an organism
A cDNA probe is made by
using reverse transcriptase to copy mRNAs from the cytoplasm of cells
using reverse transcriptase to copy DNA from the nucleus of cells
using fluorescent nucleotides to label RNA with cells
using reverse transcriptase to copy premRNAs from the nucleus of cells
cDNA probes are used to
determine which pre-mRNAs are present within the nucleus of a cell
determine the nucleotide sequence of a given gene
determine which genes have been expressed by a cell
determine which genes are present within the nucleus of a cell
A proteome is
all types of RNA present within a cell
all of the proteins present within a cell
all of the mRNA present within a cell
all of the genes present within a cell
A genome is
Which of the following is true of a cell's proteome?
It represents all of the proteins within a cell.
It is equivalent to the number of mRNAs within a cell.
It includes all types of DNA and RNA within a cell.
It represents all of the genes within a cell.
Where is DNA located within plant cells?
In chloroplasts only
In mitochondria only
In chloroplasts and the nucleus only
In all of these organelles
In the nucleus only
Regarding extranuclear DNA, where is it located within eukaryotic cells?
within the nucleolus
within smooth and rough endoplasmic reticulum
within cytoplasmic ribosomes
within the cytoskeleton
within mitochondria and chloroplasts
What is the probable origin of extranuclear DNA in eukaryotes?
It is DNA that leaked out of the nucleus during evolution of eukaryotic cells.
It is the result of viral infections of eukaryotic cells.
It became part of the cytoskeletal structure of eukaryotic cells.
It was present in prokaryotes that became endosymbionts of eukaryotic cells.
In current studies of human ancestry based on maternal inheritance, which of the following approaches is used?
the entire genome is analyzed
mitochondrial DNA is analyzed
cDNA probes and microarrays are used
the entire proteome is analyzed
In eukaryotic organisms, mitochondrial DNA
is inherited only from the male parent
is not passed from parent to offspring
is inherited from both parents
is inherited only from the female parent
is only present if the offspring has been infected by a virus
Analysis of human mitochondrial DNA can be use to determine
whether a person is related to a dead person
whether a person is related to another living person
in what region of the world a person's ancestors lived
How can a researcher locate species that have genes which are homologous to a given human gene?
By using the computer program BLAST
By performing a microarray analysis
By using cDNA probes to locate mRNA
By determining the sequence of the human gene
How can the computer program BLAST be used?
To determine which genes are expressed in a cell by microarray analysis
To determine the amino acid sequence of a new protein by "protein sequencing"
To locate genes of other species that are homologous to a known gene
To determine the nucleotide sequence of a new gene by "gene sequencing"
To determine which animal species have proteins similar to a given human protein based on amino acid sequence.
The human genome project determined that human DNA consists of
300,000 nucleotides
3 million nucleotides
3 million genes
3 billion proteins
3 billion nucelotides
What was the purpose of the human genome project?
To determine whether all humans have the same type of genes
To determine which genes are expressed in each type of human cell
To determine the amino acid sequence of all proteins in human cells
To determine the nucleotide sequence of all DNA in human cells
What was the source of DNA used in the human genome project?
DNA was obtained from 100 people who agreed to have their names published.
DNA was obtained anonymously from 100 people, but only a few samples were used.
DNA was obtained anonymously from about 10,000 people and pooled.
DNA was obtained from several samples used in forensic investigations.
DNA was obtained from a single person--the man in charge of the project.
