Q: Which of the following best describes the flow of genetic information according to the Central Dogma of molecular biology?

$$\text{DNA} \rightarrow \text{RNA} \rightarrow \text{Protein}$$

Question 1

Which experiment provided the strongest evidence that DNA, and not protein, is the genetic material in cells?

Accepted Answer

Hershey and Chase's experiment using bacteriophages labeled with radioactive isotopes

Question 2

During which phase of mitosis do chromosomes align at the cell's equatorial plate, and how many chromatids does each chromosome have at this stage in a human somatic cell?

Accepted Answer

Metaphase; each chromosome has two chromatids

Question 3

A cell with 8 chromosomes undergoes meiosis. How many chromosomes and chromatids will each daughter cell have after meiosis II is complete?

Accepted Answer

4 chromosomes and 4 chromatids

Question 4

Which enzyme is responsible for synthesizing the RNA primer during DNA replication in prokaryotes?

Accepted Answer

Primase

Question 5

What is the main function of telomerase in eukaryotic cells?

Accepted Answer

To extend the 3' ends of linear chromosomes, preventing loss of genetic material during replication

Question 6

Which of the following best describes the flow of genetic information according to the Central Dogma of molecular biology?

Accepted Answer

$$	ext{DNA} ightarrow 	ext{RNA} ightarrow 	ext{Protein}$$

Question 7

Which of the following mutations is most likely to result in a nonfunctional protein due to a premature stop codon?

Accepted Answer

Nonsense mutation

Question 8

In the lac operon of E. coli, what happens when lactose is present and glucose is absent?

Accepted Answer

The operon is highly expressed due to removal of the repressor and activation by CAP-cAMP

Question 9

Which of the following best explains why eukaryotic gene expression is more complex than prokaryotic gene expression?

Accepted Answer

Eukaryotic DNA is packaged into chromatin, requiring additional regulation at multiple levels

Question 10

A pedigree shows a trait that appears in every generation and affects both males and females equally. What is the most likely mode of inheritance?

Accepted Answer

Autosomal dominant

Question 11

Which of the following statements about PCR (Polymerase Chain Reaction) is correct?

Accepted Answer

Taq polymerase is used because it is stable at high temperatures required for DNA denaturation

Question 12

A woman who is heterozygous for a gene (Aa) and a man who is homozygous recessive (aa) have a child. What is the probability that the child will be homozygous recessive?

Accepted Answer

$$\frac{1}{2}$$

Question 13

Which of the following is a function of tumor-suppressor genes?

Accepted Answer

They encode proteins that inhibit cell division or promote apoptosis

Question 14

Which of the following best describes the outcome of Meselson and Stahl's experiment on DNA replication?

Accepted Answer

DNA replication is semiconservative, with each daughter molecule containing one old and one new strand

Question 15

Which of the following is a key difference between prokaryotic and eukaryotic transcription?

Accepted Answer

Eukaryotic mRNA undergoes capping, polyadenylation, and splicing, while prokaryotic mRNA does not

Question 16

A point mutation changes the codon $$	ext{GAA} ($$glutamic acid) to $$	ext{GUA} ($$valine). What type of mutation is this?

Accepted Answer

Missense mutation

Question 17

Which of the following best describes the role of CRISPR in biotechnology?

Accepted Answer

It allows for targeted editing of specific DNA sequences in living cells

Question 18

Which of the following is true about induced pluripotent stem cells (iPS cells)?

Accepted Answer

They are adult cells reprogrammed to an embryonic-like pluripotent state

Question 19

A patient inherits a mutated RAS gene that is always active. What is the most likely consequence?

Accepted Answer

Uncontrolled cell division leading to increased cancer risk

Question 20

Which of the following best explains why a frameshift mutation (caused by insertion or deletion of one nucleotide) is often more severe than a missense mutation?

Accepted Answer

It alters the reading frame, changing every amino acid downstream of the mutation

BIOL 190A Final Exam Study Guide: DNA, Gene Expression, and Cell Division

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