chapter 10 review pt 1

We would expect that a 15-nucleotide sequence that includes a stop codon at the end (as part of the 15-nucleotide sequence) will direct the production of a polypeptide that consists of four amino acids. three amino acids. five amino acids. two amino acids.

four amino acids

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? prevention of the formation of glycoproteins inhibition of reverse transcriptase inhibition of DNA polymerase destruction of amino acids that are vital to viral protein synthesis

inhibition of reverse transcriptase

The type of mutation represented below is a(n) _____. The big red fly had one eye (wild type) The fbi gre dfl yha don eey (mutant) insertion deletion single base substitution addition of a codon

insertion

A geneticist found that a particular mutation had no effect on the polypeptide encoded by a gene. This mutation probably involved _____. deletion of one nucleotide alteration of the start codon insertion of one nucleotide substitution of one nucleotide

substitution of one nucleotide

The copying mechanism of DNA is most like carving a figure out of wood. dripping water out of a faucet. taking a picture of yourself and of your reflection in a mirror. mixing flour, sugar, and water to make bread dough.

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

Which of the following is NOT true about the genetic code? The genetic code is ambiguous. The genetic code is almost universal. The genetic code is redundant. The nucleotides making up the codons occur in a linear order along the DNA and RNA with no gaps or punctuation separating the codons.

the genetic code is ambiguous

Frederick Griffith was one of the leading scientists looking at the genetic role of DNA. He was working on two strains of Streptococcus pneumoniae: The rough strain (R) did not cause pneumonia, but the smooth strain (S) did. When Griffith heat-killed the S strain and gave both the heat-killed S strain and the R strain to mice, the mice developed pneumonia and died. What happened in this experiment that caused the mice to develop pneumonia? The R strain mutated and thus was able to cause pneumonia. There was more of the R strain added than previously. The immune systems of the mice were unable to cope with both the S and R strains simultaneously. Even though the S strain had been heat-killed, it changed the R strain.

Even though the S strain had been heat-killed, it changed the R strain.

The nucleotide sequence of a DNA codon is GTA. A messenger RNA molecule with a complementary codon is transcribed from the DNA. In the process of protein synthesis, a tRNA pairs with the mRNA codon. What is the nucleotide sequence of the tRNA anticodon? CAT CUT GUA CAU

GUA

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 replicated more slowly than eukaryotic DNA. Prokaryotic DNA is single-stranded. Prokaryotes do not replicate their DNA. Prokaryotic DNA is much smaller than eukaryotic DNA.

Prokaryotic DNA is much smaller than eukaryotic DNA.

Exposure to the HIV virus doesn't necessarily mean that a person will develop AIDS. Some people have genetic resistance to infection by HIV. Dr. Stephen O'Brien from the U.S. National Cancer Institute has recently identified a mutant form of a gene, called CCR5, that can protect against HIV infection. The mutation probably originated in Europe among survivors of the bubonic plague. The mutated gene prevents the plague bacteria from attaching to cell membranes and, therefore, from entering and infecting body cells. Although the HIV virus is very different from the bacteria that causes the plague, both diseases affect the exact same cells and use the same method of infection. The presence of the mutated gene in descendants of plague survivors helps prevent them from contracting AIDS. Pharmaceutical companies are using this information as the basis for a new approach to AIDS prevention. This could be very important in areas of the world where the mutation is scarce or absent, such as Africa. Imagine that a pharmaceutical company was successful at producing a drug based on the CCR5 gene product that is effective at preventing the contraction of AIDS. However, shortly after the drug has been in use, patients and doctors report that the drug is not as effective as it once was. What is the most likely explanation for this result? The DNA of white blood cells of the people taking the drug have mutated to become resistant to the drug. The HIV virus gained mutations in its DNA genome in order to become resistant to the actions of the drug. Some HIV viruses have genetic variations in the RNA genome that provide resistance to the actions of the drug. The people taking the drug have built up a tolerance to the drug.

Some HIV viruses have genetic variations in the RNA genome that provide resistance to the actions of the drug.

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

The dod idn ote at.

The way that genetic material of a bacteriophage enters a bacterium is most like the way that skin lotion is rubbed onto the hands. a person swallows a pill. a drug is injected with a hypodermic needle. water soaks into a sponge.

a drug is injected with a hypodermic needle.

It is possible to synthesize proteins in vitro (in a test tube) without the use of living cells. If starting from a mature mRNA transcript, which of the following components would not be needed to do this? ribosomes adenine molecules tRNAs amino acids

adenine molecules

Genetic mutations __________. are most common in body parts that are used frequently are mainly caused by diseases associated with fetal development can occur naturally are always passed on to the next generation

can occur naturally

Exposure to the HIV virus doesn't necessarily mean that a person will develop AIDS. Some people have genetic resistance to infection by HIV. Dr. Stephen O'Brien from the U.S. National Cancer Institute has recently identified a mutant form of a gene, called CCR5, that can protect against HIV infection. The mutation probably originated in Europe among survivors of the bubonic plague. The mutated gene prevents the plague bacteria from attaching to cell membranes and, therefore, from entering and infecting body cells. Although the HIV virus is very different from the bacteria that causes the plague, both diseases affect the exact same cells and use the same method of infection. The presence of the mutated gene in descendants of plague survivors helps prevent them from contracting AIDS. Pharmaceutical companies are using this information as the basis for a new approach to AIDS prevention. This could be very important in areas of the world where the mutation is scarce or absent, such as Africa. The most likely method by which the mutated CCR5 gene prevents AIDS is by rupturing the nuclear membrane. covering the cell membrane. attacking and destroying the HIV virus particles. coding for a protective protein in the cell membrane.

coding for a protective protein in the cell membrane.

A virus infects a cell and randomly inserts many short segments of DNA containing a stop codon throughout the organism's chromosomes. This will probably cause _____. no deleterious effects, as long as the stop codons are not also inserted into tRNA incorrect pairing between mRNA codons and amino acids the DNA to break up into thousands of short segments manufactured proteins to be short and defective

manufactured proteins to be short and defective

The translation process requires all of the following: _____. peptide bonding, ribosomes, RNA polymerase RNA polymerase, AUG codons, transfer RNA transfer RNA, ribosomes, AUG codons ribosomes, RNA polymerase, peptide bonding

transfer RNA, ribosomes, AUG codons

In the 1920s, Frederick Griffith conducted an experiment in which he mixed the dead cells of a bacterial strain that can cause pneumonia with live cells of a bacterial strain that cannot. When he cultured the live cells, some of the daughter colonies proved able to cause pneumonia. Which of the following processes of bacterial DNA transfer does this experiment demonstrate? transposition conjugation transformation transduction

transformation

Which of the following processes takes place in the cytoplasm? synthesis of the two ribosomal subunits removal of introns from RNA replication of DNA translation

translation

Hershey and Chase's experiment allowed them to discern whether DNA or proteins contain genetic information because __________. viruses consist only of proteins and DNA and only the DNA was injected into the host cells the enzymes used in host cell replication are identical to those used in phage replication the host cells became radioactive they could grow the viruses in culture media

viruses consist only of proteins and DNA and only the DNA was injected into the host cells