AP Biology Molecular Biology

A biochemist isolates, purifies, and combines in a test tube a variety of molecules needed for DNA replication. When she adds some DNA to the mixture, replication occurs, but each DNA molecule consists of a normal strand paired with numerous segments of DNA a few hundred nucleotides long. What has she probably left out of the mixture?

• DNA ligase
• nucleotides
• DNA polymerase III
• Okazaki fragments

Which of the following help(s) to hold the DNA strands apart while they are being replicated?

• RNA primase
• single–strand binding proteins
• DNA polymerase I
• DNA ligase

What is meant by the description "antiparallel" regarding the strands that make up DNA?

• The twisting nature of DNA creates nonparallel strands.
• One strand is positively charged and the other is negatively charged.
• The 5' to 3' direction of one strand runs counter to the 5' to 3' direction of the other strand.
• Base pairings create unequal spacing between the two DNA strands

The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following?

• The same codons in different organisms translate into the different amino acids.
• A gene from an organism can theoretically be expressed by any other organism.
• All organisms have experienced convergent evolution.
• DNA was the first genetic material.

Tags

NGSS.HS-LS1-1

NGSS.HS-LS4-1

What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?

• It catalyzes the lengthening of telomeres.
• It synthesizes RNA nucleotides to make a primer.
• It unwinds the parental double helix.
• It joins Okazaki fragments together.

What is meant that DNA replication follows a “semi-conservative” model?

• After DNA replication, each strand contains one side that is a parental strand and the other side is a daughter strand.
• After DNA replication, one completed strand contains only parental DNA while the other contains only daughter DNA.
• None of these identify the “semi-conservative” model.
• After DNA replication, one completed strand contains a mixture of both parental DNA and daughter DNA dispersed throughout the strand.

Which scientist(s) stated that DNA contains phosphorus while proteins contain sulfur?

• Meselson & Stahl
• Hershey & Chase
• Watson & Crick
• Franklin & Watkins

Which scientist(s) mixed a heat-killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form?

• Griffith
• Watson & Crick 
• Meselson & Stahl
• Chargaff

Tags

NGSS.HS-LS3-2

Which scientist(s) said that adenine and guanine equals thymine and cytosine

• Franklin & Watkins
• Chargaff
• Griffith
• Hershey & Chase

Which scientists determined that DNA was a double helix?

• Franklin & Watkins
• Hershey & Chase
• Meselson & Stahl
• Watson & Crick