Chapter 10 (Mastering Biology)

A new disease emerges and exists only as a free-floating virus. Which of the following will make antibodies against this?

B cells

Emerging viruses that infect human cells can originate from __________.

a virus spreading from one host species to humans

The four bases contained in DNA are _____.

adenine, guanine, cytosine, thymine

The "one gene-one polypeptide" theory states that

the function of an individual gene is to dictate the production of a specific polypeptide.

The information carried by a DNA molecule is in _____.

the order of the nucleotides in the molecule

What did the structure of DNA's double helix suggest about DNA's properties?

1. DNA can be replicated by making complimentary copies of each strand. 2. DNA can change. Errors in copying can result in changes in the DNA sequence that could be inherited by future generations. 3. DNA stores genetic information in the sequence of its bases.

In the 1950s, when Watson and Crick were working on their model of DNA, which concepts were well accepted by the scientific community?

1. Genes are located on chromosomes 2. Chromosomes are found in the nucleus 3. Chromosomes are made up of protein and nucleic acid

What are the chemical components of a DNA molecule?

1. Nitrogenous bases 2. Sugars 3. Phosphate groups

Hershey and Chase used _____ to radioactively label the T2 phage's proteins.

35s

When one DNA molecule is copied to make two DNA molecules, the new DNA contains

50% of the parent DNA

Any change in the nucleotide sequence of DNA is called

A mutation

What kind of virus is HIV?

A retrovirus

The shape of a DNA molecule is most like

A twisted rope ladder

Which statement about DNA replication is FALSE? A. DNA ligase adds nucleotides to the lagging strand. B. DNA polymerase builds a new strand by adding DNA nucleotides one at a time. C. Because the two strands of parental DNA run in opposite directions, the new strands must be made in different ways. D. The lagging strand is made of a series of pieces that must be joined together to make a continuous strand. E. The two strands of parental DNA are separated during DNA replication.

A. DNA ligase adds nucleotides to the lagging strand.

Which of the following options best depicts the flow of information when a gene directs the synthesis of a cellular component? A. DNA → RNA → protein B. DNA → tRNA → mRNA → protein C. RNA → DNA → RNA → protein D. protein → RNA → DNA

A. DNA → RNA → protein

Which statement about DNA replication is CORRECT? A. The leading strand is built continuously, and the lagging strand is built in pieces. B. The lagging strand is one of the strands of parental DNA. C. DNA ligase helps assemble the leading strand. D. The leading strand is one of the strands of parental DNA. E. The lagging strand is built continuously.

A. The leading strand is built continuously, and the lagging strand is built in pieces.

Which of the following is true about double-stranded DNA? A. It is shapes like a triple helix B. Its strands have a sugar-phosphate backbone C. The two strands are identical. D. Adenine and uracil are present in equal amounts.

B. Its strands have a sugar-phosphate backbone

Which of the following statements about herpesviruses is false? A. Herpesviruses may remain dormant for long periods of time while inside the host cell nucleus. B. Herpesviruses may cause cold sores or genital sores to appear during times of physical or emotional stress. C. Herpesviruses reproduce inside the host cell's mitochondria. D. Herpesviruses acquire their envelopes from the host cell nuclear membrane.

C. Herpesviruses reproduce inside the host cell's mitochondria.

Which of the following statements about treatment or prevention of a prion infection is true? A. Antibiotic therapies such as penicillin are very effective cures. B. Preventative vaccines have recently been shown to be effective in preventing prion infections. C. There is no known treatment or cure for prion infections. D. High doses of anti-inflammatory drugs such as ibuprofen reduce the symptoms of prion infections.

C. There is no known treatment or cure for prion infections.

The drug AZT was one of the first drugs used to treat HIV. Which of the following drug actions would prevent the spread of HIV without harming the host cell? A. prevention of the formation of glycoproteins B. inhibition of DNA polymerase C. inhibition of reverse transcriptase D. destruction of amino acids that are vital to viral protein synthesis

C. inhibition of reverse transcriptase

What is the transcription product of the sequence GCTAGCGATGAC?

CGAUCGCUACUG

Which of the following statements regarding DNA is false? A. One DNA molecule can include four different nucleotides in its structure. B. DNA uses the sugar deoxyribose. C. DNA molecules have a sugar-phosphate backbone. D. DNA uses the nitrogenous base uracil

D. DNA uses the nitrogenous base uracil

Which of the following statements regarding RNA is false? A. One RNA molecule can include four different nucleotides in its structure. B. RNA uses the nitrogenous base uracil C. RNA molecules have a sugar-phosphate backbone D. RNA uses the sugar dextrose

D. RNA uses the sugar dectrose

Which of the following statements about ribosomes is false? A. Ribosomal subunits are made of proteins and ribosomal RNA. B. Each ribosome has two binding sites for tRNA molecules. C. A ribosome consists of two subunits. D. The ribosomes of prokaryotes and eukaryotes are the exactly the same in structure and function.

D. The ribosomes of prokaryotes and eukaryotes are the exactly the same in structure and function.

Which of the following statements regarding the flow of genetic information is false? A. Eukaryotic mRNA is processed in several ways before export out of the nucleus. B. Ribosomes function as factories that coordinate the functioning of mRNA and tRNA. C. Polypeptides form proteins that determine the appearance and function of the cell and organism. D. Transcription occurs in the cytoplasm of eukaryotic cells.

D. Transcription occurs in the cytoplasm of eukaryotic cells.

What did Rosalind Franklin's famous photo 51 show?

DNA is a helix

Early, flawed DNA models proposed by Watson and Crick and by Linus Pauling correctly described which property of DNA?

DNA is composed of sugars, phosphates, and bases.

The molecule that seals the gaps between the pieces of DNA in the lagging strand is

DNA ligase

Which of the following build(s) new strands of DNA?

DNA polymerases

The radioactive isotope 32P labels the T2 phage's _____.

DNa

Which of the following has the greatest potential as a cancer treatment?

Find a way to turn off the gene for making telomerase in cancer cells, since the cells would stop dividing when the telomeres were gone.

If one strand of DNA is CGGTAC, then the corresponding strand would be

GCCATG

Who demonstrated that DNA is the genetic material of the T2 phage?

Hershey and Chase

During the lytic cycle, but not the lysogenic cycle, _____.

whole viruses leave the host cell to infect other cells

Below are three statements. Which of the following choices properly matches the statements with the correct biological processes? I. This occurs in the nucleus of eukaryotic cells. II. Transfer RNAs bind amino acids in the cytoplasm. III. A polymerase enzyme is required.

I: replication; II: translation; III: transcription

The best flu vaccine would work to prevent people from which of the following?

Influenza A, B, and C

In the early 1950s, many researchers were racing to describe the structure of DNA using different approaches. Which of the following statements is true?

Jim Watson and Francis Crick built theoretical models, incorporating current knowledge about chemical bonding and X-ray data.

After allowing phages grown with bacteria in a medium that contained 32P and 35S, Hershey and Chase used a centrifuge to separate the phage ghosts from the infected cell. They then examined the infected cells and found that theycontained _____, which demonstrated that _____ is the phage's genetic material.

Labeled DNA DNA

A disease that spreads rapidly around the world is called a(n) ___________.

Pandemic

Prokaryotic organisms have a single origin of replication, whereas eukaryotic organisms have many origins where replication occurs simultaneously. Which of the following is the most probable reason for this observation?

Prokaryotic DNA is much smaller than eukaryotic DNA.

You are an immunologist working on a new flu vaccine that attacks molecules with the same basic make-up as hemagglutinin. What is your area of expertise?

Proteins

During DNA replication, which nucleotide will bind to an A nucleotide in the parental DNA?

T

What kind of cell can recognize infected cells and kill them directly?

T cells

Which of the following statements characterizes the lytic cycle of a viral infection?

The cycle typically leads to the lysis of the host cell.

Erwin Chargaff observed that the proportions of adenine (A) and thymine (T) bases were always equal, as were the proportion of guanine (G) and cytosine (C). Chargaff's observation suggests which of the following statements?

The data suggest that A would always pair with T and G would always pair with C in a DNA molecule.

Consider the following sentence: "The dog did not eat." Which of the following variations of this sentence is most like a frameshift mutation?

The dod idn ote at.

Consider the following sentence: "The dog did not eat." Which of the following variations of this sentence is most like a base substitution mutation?

The doe did not eat

The transfer of genetic information from DNA to RNA is called

Transciption

How do retroviruses such as HIV differ from other viruses?

They contain the enzyme reverse transcriptase.

When messenger RNA (mRNA) is being transcribed, the RNA base _____ always pairs with the base _____ in DNA.

U ... A

Which of the following statements regarding viral diseases is false?

Very few new human diseases have originated in other animals because the genetic differences are too great.

HIV does the greatest damage to

White blood cells

The way that genetic material of a bacteriophage enters a bacterium is most like the way that

a drug is injected with a hypodermic needle

Which of the following describes a complete nucleotide?

a nitrogenous base, a sugar, and a phosphate group

Many enzymes are named for the substrate on which they work, either to build or disassemble molecules. Also, enzyme names often end in "-ase." For example, lactase is the enzyme that breaks down lactose. With a name like "telomerase," we can deduce that telomerase is probably:

an enzyme that regulates the assembly of DNA at the ends of chromosomes

F plasmids _____.

contain the genes necessary to make a sex pilus

Which of the following human activities has contributed to an increase in the number of bacteria having R plasmids?

heavy use of antibiotics in medicine and in agriculture

Where do transcription and translation occur in prokaryotic cells?

in the cytoplasm

The phage reproductive cycle that kills the bacterial host cell is known as a _____ cycle.

lytic

When a T2 bacteriophage infects an Escherichia coli cell, which part of the phage enters the bacterial cytoplasm?

only the DNA

A physical or chemical agent that changes the nucleotide sequence of DNA is called a(n)

mutagen

One type of virus that infects bacteria is called a

phage

What are telomeres?

regions of DNA at the end of chromosomes which do not code for making proteins

The copying mechanism of DNA is most like

taking a picture of yourself and of your reflection in the mirror

Which of the following takes place during translation?

the conversion of genetic information from the language of nucleic acids to the language of proteins