Chapter 12 Biology

What did Avery conclude caused transformation?

DNA was the transforming factor.

Which scientist made x-ray diffraction photos of DNA?

Franklin

Which of the following best describes Rosalind Franklin's contribution to our understanding of the structure of DNA?

She purified large amounts of DNA, stretched the fibers so the strands were parallel, and used an X-ray beam to produce an image of the molecule.

Rosalind Franklin contributed to the understanding of DNA by

producing images of DNA molecules using X-rays.

Watson and Crick discovered the two strands in DNA

run in opposite directions.

In which cells is the accurate transmission of information most important?

sex cells

Griffith called the process he observed transformation because

the harmless bacteria had been transformed

Griffith's experiments advanced the study of genetics by proving that

there is a chemical that contains genetic information that can be passed from one organism to another.

Because of base pairing in DNA, the percentage of

thymine molecules in DNA is about equal to the percentage of adenine molecules

In both prokaryotes and eukaryotes, how many copies of the chromosome are left after replication?

2

What property of DNA does bacterial transformation illustrate?

Bacterial DNA can move into another bacteria and function.

Which of the following statements correctly describes Chargaff's contribution to the study of DNA?

Chargaff showed that adenine and thymine were found in equal percentages in DNA, but he did not know this was because of base-pairing.

What stores information in a cell?

DNA

Why did Hershey and Chase label the viral DNA with radioactive phosphorous and not radioactive sulfur?

DNA contains phosphorus and no sulfur.

In what way is DNA like a book?

DNA has stored information, that can be copied and passed on.

What happens when a piece of DNA is missing?

Genetic information is lost.

What structural problem prevents adenine from pairing with guanine?

The bases are both long.

What would have happened if Avery had added an enzyme that digested all the nucleic acids to the mixture of heat-killed bacteria, added the mixture to harmless bacteria, and injected the mixture into mice?

The harmless bacteria would not have been transformed, and the mice would have lived.

What happened when Griffith injected mice with the harmless, R-strain bacteria

The mouse lived.

Which scientist(s) figured out that the shape of a DNA molecule is a double helix?

Watson and Crick

Which of the following forms a base pair with thymine?

adenine

What do bacteriophages infect?

bacteria.

In both prokaryotes and eukaryotes, DNA replication happens

before cell division.

Which of the following is a nucleotide found in DNA?

deoxyribose + phosphate group + cytosine

In eukaryotes, DNA

is located in the nucleus.

Which bacteria killed the mice in Griffith's transformation experiment?

live, harmless bacteria and heat-killed, harmful bacteria

What is inside a bacteriophage?

nucleic acid