DNA

A scientist uses radioactive isotopes to label a double-stranded molecule of DNA. Then the DNA undergoes replication in a non-radioactive medium. Where are the two original radioactive strands of DNA?

• Both strands are broken apart.

• Both strands are intact, and both are part of the same molecule of DNA.

• One strand is intact, and the other strand is broken apart and distributed among the new DNA molecules.

• Both strands are broken apart, and their pieces are distributed among the new DNA molecules.

The enzyme DNA (nuclease / polymerase) joins (amino acids / nucleotides) to synthesize a new (complementary / opposite) DNA strand.

• polymerase nucleotides complementary

• nuclease

  amino acids

  opposite DNA strand.

• d.

***In DNA, thymine always pairs with (cytosine / guanine / adenine) and cytosine always pairs with (adenine / guanine / thymine) by forming (hydrogen bonds / covalent bonds) across complementary strands.

• adenine

  guanine

  hydrogen bonds

• guanine

  thymine

  hydrogen bonds

• cytosine

  thymine

  covalent bonds

Which of the following events occurs in DNA replication in prokaryotes?

• Regulatory proteins bind to all of the nucleotides on the DNA molecule.

• Enzymes “unzip” the DNA molecule by breaking ionic bonds between base pairs.

• Replication starts from a single point and proceeds in two directions until the entire chromosome is copied.

• Replication starts from multiple points and proceeds in two directions until the entire chromosome is copied.

How does DNA influence social structures in human societies?

• DNA determines social class and status.

• DNA influences physical traits that can affect social interactions.

• DNA directly dictates cultural practices.

• DNA has no impact on social structures.

What role does DNA play in the study of human migration patterns?

• DNA is irrelevant to migration studies.

• DNA helps trace lineage and ancestral origins.

• DNA can predict future migration trends.

• DNA determines the success of migration.

How has DNA evidence impacted the field of criminal justice?

• DNA evidence is not admissible in court.

• DNA evidence has no impact on criminal justice.

• DNA evidence is used to exonerate or convict individuals.

• DNA evidence is only used in civil cases.

In what way does DNA contribute to our understanding of historical populations?

• DNA provides no information about historical populations.

• DNA helps reconstruct family trees and genetic diversity.

• DNA can rewrite historical events.

• DNA is used to date archaeological sites.

How is DNA used in the field of genealogy?

• DNA is not used in genealogy.

• DNA helps establish family connections and ancestry.

• DNA can predict future family events.

• DNA determines family wealth.

What is the significance of DNA in the study of human evolution?

• DNA has no significance in human evolution studies.

• DNA provides evidence of common ancestry and evolutionary changes.

• DNA can predict future evolutionary trends.

• DNA determines the speed of evolution.