Question 1

MRSA is a variant of

Accepted Answer

MRSA stands for methicillin-resistant Staphylococcus aureus, indicating that it is a variant of the bacterium Staphylococcus aureus.

Question 2

During initiation,the sequence of DNA to which RNA polymerase binds most tightly is the

Accepted Answer

During initiation, the RNA polymerase binds most tightly to the promoter sequence on DNA. The promoter region is a specific sequence of DNA that signals the start of a gene and provides the binding site for RNA polymerase. This is where the transcription process begins. Choices B, C, D, and E are not directly involved in the initiation of transcription.

Question 3

Mapping studies have determined that within a group of mutants with the same growth requirements (i.e. ,the same overt phenotype),individual mutations are on different chromosomes.This indicates that

Accepted Answer

Mapping studies have determined that individual mutations with the same growth requirements are on different chromosomes. This indicates that different genes can govern different individual steps in the same biological pathway, as opposed to one gene governing all steps or different genes governing the same step. Therefore, the correct answer is B.

Question 4

The typical treatment for people with phenylketonuria is a diet low in phenylalanine.If one were to design a gene therapy for this disease,which would be the most promising approach?

Accepted Answer

Engineering a gene that codes for the enzyme that converts phenylalanine to tyrosine would be the most promising approach for gene therapy for phenylketonuria. This would allow individuals with phenylketonuria to break down phenylalanine in their diet and prevent toxic build-ups, just like people without the disease.

Question 5

Which discovery caused the modification of the "one gene-one protein" hypothesis to the "one gene-one polypeptide" hypothesis?

Accepted Answer

The discovery that proteins can be made up of multiple polypeptide chains led to the modification of the hypothesis, as each chain is encoded by a separate gene.

Question 6

In bacteria,_______ kind(s)of RNA polymerase catalyze(s)the synthesis of RNA from DNA.

Accepted Answer

In bacteria, only one kind of RNA polymerase is responsible for catalyzing the synthesis of RNA from DNA. This RNA polymerase is composed of multiple subunits and is able to transcribe different kinds of RNA, including messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA).

Question 7

Tetracycline,but not penicillin,is able to kill MRSA because tetracycline

Accepted Answer

Tetracycline inhibits protein synthesis in bacteria, which is essential for bacterial growth and reproduction. MRSA (methicillin-resistant Staphylococcus aureus) is a type of bacteria that has developed resistance to penicillin and other beta-lactam antibiotics, but it is still susceptible to tetracycline. This is because MRSA has not yet developed resistance to tetracycline's mechanism of action, which is different from beta-lactam antibiotics.

Question 8

Which molecule(s)is/are not required for transcription?

Accepted Answer

A primer is not required for transcription. Transcription involves the synthesis of an RNA molecule using a DNA template and appropriate ribonucleoside triphosphates by RNA polymerase. Unlike DNA replication, transcription does not require a primer to initiate synthesis.

Question 9

Which statement about the flow of genetic information is true?

Accepted Answer

The flow of genetic information starts with DNA, which encodes genetic information in the form of a sequence of nucleotides. This genetic information is then transcribed into RNA, which is a copy of the DNA sequence. The RNA is then translated into proteins, which carry out various functions in the cell. Therefore, choice D, which states that DNA encodes information that is translated into RNA, and RNA encodes information that is translated into proteins, is the correct statement about the flow of genetic information.

Question 10

Use the following to answer questions :
Suppose that a wild-type bacterium can synthesize substance D,but various mutant strains cannot.We know that substance D is synthesized from substance X in a pathway that involves three intermediate substances (A,B,and C),but we do not know the order of the steps in the pathway.Below is a table of four different mutant strains that have been tested for their ability to grow on the various substances.The plus sign means that the strain can grow on that substance;the negative sign means that the strain cannot grow on that substance. 
-Suppose that another strain (strain 5)can grow on substance B but cannot grow on substance C.What can we infer from this observation?

Accepted Answer

The answer of Use the following to answer questions :
Suppose...

Question 11

RNA polymerase is a

Accepted Answer

RNA polymerase is an enzyme that synthesizes RNA from a DNA template during transcription. Enzymes are usually proteins, so C is the best choice. A, B, D, and E are incorrect as RNA polymerase is not a polysaccharide, lipid, nucleic acid, or carbohydrate/lipid mixture.

Question 12

What is the most likely reason that alkaptonuria is a recessive disease?

Accepted Answer

Alkaptonuria is caused by a mutation in the homogentisic acid oxidase gene, which results in a deficiency of the enzyme needed to break down homogentisic acid. This acid builds up in the body and can cause various symptoms, including darkening of urine, joint pain, and cartilage and heart valve problems. Since having half the typical amount of homogentisic acid oxidase is sufficient to break down the toxin by-product, it is likely that the disease is recessive. If the disease were dominant, only one copy of the mutated gene would be needed for the disease to manifest. However, with a recessive inheritance pattern, an individual must inherit two copies of the mutated gene (one from each parent) to develop the disease.

Question 13

The "adapters" that allow translation of the four-letter nucleic acid language into the 20-letter protein language are called

Accepted Answer

Transfer RNAs, or tRNAs, are the adapters that allow translation of the four-letter nucleic acid language into the 20-letter protein language. Each tRNA carries a specific amino acid and has an anticodon that matches a codon on the mRNA, allowing for accurate placement of the amino acid into the growing protein chain.

Question 14

Use the following to answer questions :
Suppose that a wild-type bacterium can synthesize substance D,but various mutant strains cannot.We know that substance D is synthesized from substance X in a pathway that involves three intermediate substances (A,B,and C),but we do not know the order of the steps in the pathway.Below is a table of four different mutant strains that have been tested for their ability to grow on the various substances.The plus sign means that the strain can grow on that substance;the negative sign means that the strain cannot grow on that substance. 
-According to the data above,what is the most likely order of the pathway?

Accepted Answer

The answer of Use the following to answer questions :
Suppose...

Question 15

Which type of molecule transfers information from mRNA to protein?

Accepted Answer

tRNA (transfer RNA) is the type of molecule that transfers information from mRNA to protein by carrying specific amino acids to the ribosome during protein synthesis. DNA carries genetic information, but it is not directly involved in the transfer from mRNA to protein. Polysaccharides, lipids, and proteins are not directly involved in this process either.

Question 16

Which type of molecule is most involved in the transfer of genetic information from the nucleus to the cytoplasm?

Accepted Answer

mRNA (messenger RNA) is the molecule that carries the genetic information from DNA in the nucleus to the ribosomes in the cytoplasm, where it is translated into proteins. tRNA (transfer RNA) and proteins are involved in the process of translation, but not in the transfer of genetic information from the nucleus to the cytoplasm. Lipids are not directly involved in the transfer of genetic information.

Question 17

Transcription is the process by which

Accepted Answer

Transcription is the process by which information in DNA is used to synthesize an RNA molecule. This occurs through the formation of base-pairing interactions between the template strand of DNA and complementary ribonucleoside triphosphates to form an RNA molecule. The resulting RNA molecule is a complementary copy of the DNA sequence and can be used to direct the synthesis of a protein through the process of translation.

Question 18

The _______ strand of DNA is transcribed to produce an RNA strand by DNA bases pairing with _______ bases of RNA.

Accepted Answer

The template strand of DNA is copied during transcription, using complementary RNA bases. The coding strand is not used in transcription but it has the same sequence as the RNA molecule with the exception of T (in DNA) that is replaced by U (in RNA).

Question 19

Which statement about alkaptonuria is false?

Accepted Answer

Individuals with alkaptonuria have high levels of homogentistic acid, not low levels. This results in the characteristic darkening of urine as the acid is excreted.

Question 20

Which principle does the genetics of hemoglobin in humans illustrate?

Accepted Answer

Hemoglobin is a protein, and the genes that code for it do not code for enzymes, illustrating that not all genes code for enzymes.

Quiz 10: From Dna to Protein: Gene Expression