Genetics : Genetics

Study concepts, example questions & explanations for Genetics

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Example Questions

Example Question #1 : Central Dogma Of Biology

Which of the following best illustrates the central dogma of biology in terms of how a cell makes proteins? 

Possible Answers:

Correct answer:

Explanation:

DNA from the chromosomes first undergoes transcription to generate RNA. This RNA then undergoes translation, which is the process by which the genetic code is used to make necessary proteins. 

Example Question #1 : Central Dogma Of Biology

In the central dogma of biology, what is the name of the process that lies between RNA and protein? I.e., what process does the cell use to make protein from RNA? 

Possible Answers:

Expression

Translation

Suppression

Transcription

Replication

Correct answer:

Translation

Explanation:

Translation is the process in which RNAs are "read" by ribosomes, and the appropriate protein is made. 

Example Question #1 : Central Dogma Of Biology

If a DNA strand has the following sequence, choose the answer that has the correct mRNA sequence. 

3' ATTAGCAC 5'

Possible Answers:

TAATCGTG

GCCACTTA

UAAUCGUG

CACGATTA

ATTAGCAC

Correct answer:

UAAUCGUG

Explanation:

The mRNA will be complementary to the DNA sequence, but remember that mRNA has a uracil (U) base instead of thymine (T). If the base on the left is the DNA, the corresponding mRNA code is:

UAAUCGUG

Example Question #2 : Central Dogma Of Biology

If a DNA coding strand has the following sequence, which of the following is the sequence of the DNA template strand? 

3' ACTGTTAC 5' 

Possible Answers:

ACUGUUAC

TGACAATG

GCCGTTAC

TGUCUUTG

ACTGTTAC

Correct answer:

TGACAATG

Explanation:

The DNA template strand will be complementary to the DNA coding strand sequence. If the base on the left is the coding DNA, the corresponding template DNA strand code is:

TGACAATG

Example Question #1 : Central Dogma Of Biology

Which of the following best describes the role of the enzyme helicase? 

Possible Answers:

Unzip DNA strands by breaking the bonds between the two strands.

Repairing damaged DNA

Copying the DNA for replication

Ligating broken strands back together

Separating double-stranded RNA by breaking bonds 

Correct answer:

Unzip DNA strands by breaking the bonds between the two strands.

Explanation:

Helicase is the enzyme that breaks the bonds between the coding and template strands of DNA so that the other DNA replication machinery can access the codes. The other functions listed are important roles, but can be attributed to other enzymes.

Example Question #161 : Genetics

What is the central dogma of biology?

Possible Answers:

DNA to RNA to protein

DNA to mRNA to protein to tRNA

Protein to RNA to DNA

DNA to protein to RNA

Protein to DNA to RNA

Correct answer:

DNA to RNA to protein

Explanation:

The central dogma of biology is best described by DNA is transcribed to RNA, which is translated to protein. The genetic material (DNA) is transcribed into mRNA (RNA) which is than translated into proteins. The central dogma is an important principle in molecular biology, and it helps explain why DNA plays such an important role in genetic expression.

Example Question #11 : Central Dogma Of Biology

All of the following organisms follow the central dogma except __________.

Possible Answers:

Algae

Botulism

HIV

Deathcap

Correct answer:

HIV

Explanation:

The central dogma of biology reads that DNA goes to RNA which goes to protein. All of the following do that except for HIV, which uses reverse transcriptase in order to convert RNA to DNA which is going in reverse of the central dogma.

Example Question #162 : Genetics

A gene is the DNA segment necessary to create a protein. 

What sections of the DNA are included in a gene?

Possible Answers:

Length of DNA from a single chromosome

DNA encoding mRNA and promoter region of DNA

Promoter region of DNA

Poly-A tail and 5' cap

DNA encoding mRNA

Correct answer:

DNA encoding mRNA and promoter region of DNA

Explanation:

Given the definition that a gene is the segment of DNA necessary to create a protein, we can immediately eliminate the choices of "Poly-A tail and 5' cap" and "Length of DNA from a single chromosome." Neither of these choices correspond to a segment of DNA: the first corresponds to segments of processed mRNA, and the second to the entire length of the DNA unsegmented. Neither "DNA encoding mRNA" or "Promoter region of DNA" can be correct, as they cannot function without the other, with the promoter region allowing proteins to prepare for transcription of the DNA-encoding mRNA to be produced. 

Example Question #163 : Genetics

What is the role of the promoter region of DNA in transcription?

Possible Answers:

To open DNA downstream of the promoter region

To change the conformation of the DNA (i.e. double helix to parallel)

To open DNA upstream of the promoter region

To initiate transcription of a particular gene

To be a template for the mRNA strand to be transcribed.

Correct answer:

To initiate transcription of a particular gene

Explanation:

The promoter region of DNA does not interact with the shape of the DNA around it, eliminating all choices where change in DNA shape occurs. This leaves the answer choices of "To be a template for the mRNA strand," and "To initiate transcription of a particular gene." The promoter region is not transcribed to the mRNA that it initiates, leaving the correct answer, "To initiate transcription of a particular gene." The promoter region does this by attracting transcription factors necessary for recruitment of RNA polymerase. 

Example Question #164 : Genetics

Where does transcription take place?

Possible Answers:

Inside of the mitochondria

On ribosomes

On the outer cell membrane of the nuclear envelope

Inside of the nucleus

Inside of the rough endoplasmic reticulum

Correct answer:

Inside of the nucleus

Explanation:

The central dogma of biology occurs inside of the nucleus from DNA to modified mRNA transcripts prepared to be exported to the cytoplasm. Since the nucleus is an organelle separated from the endoplasmic reticulum and the mitochondria, those answers can be eliminated. Translation occurs on ribosomes, not transcription. It is an important distinction that transcription occurs entirely within the membranes of the nucleus, and would not be found on the outer membrane of the nuclear envelope.

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