Exam 14: Dna: the Genetic Material

Who provided X-ray diffraction photographs of purified DNA fibers that suggested a helical structure with a consistent diameter of about 2 nm and a complete helical turn every 3.4 nm?

The chemical bond connecting one nucleotide with the next along one strand of a DNA molecule is called a

In 1952, Hershey and Chase confirmed Avery's (1944) conclusion that

Endonucleases and exonucleases are enzymes that can remove nucleotides from a polynucleotide chain.An endonuclease removes nucleotides _______ while an exonuclease removes nucleotides _____________.

If a short sequence of DNA is 5' AATTGCCGT 3', its complement is

Information obtained by Franklin from X-ray crystallography on DNA suggested that it is shaped like a

Who demonstrated that phage genetic material is DNA and not protein?

The method of DNA replication, where each original strand is used as a template to build a new strand, is called the

As the two strands of DNA are unraveled, which enzyme relieves the strain on the two strands?

You decide to repeat the Meselson-Stahl experiment, except this time you plan to grow the cells on light ¹⁴N medium for many generations and then transfer them to heavy ¹⁵N medium and allow them to grow for 2 additional generations (2 rounds of DNA replication).If the semiconservative model of DNA replication is correct, what is the expected distribution of DNA in the density gradient after two rounds of replication?

I think the proactive stance is a better attitude to promote than after-the-fact worrying! When planning a long week of sunbathing on the beach, What type of DNA damage should sunbathers be aware of before hitting the beach?

If 14% of the nucleotides from a DNA molecule contain the base T, what percent will contain the base G?

Watson and Crick developed a model of DNA in which the two strands twist into the shape of a ________________.

Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder.Patients with XP exhibit a cellular hypersensitivity to ultraviolet (UV) radiation, a high incidence of skin cancer and premature aging.Based on these clinical characteristics, what is the most likely cause for this disease?

If we think of the DNA double helix as a twisted ladder, what makes up the rungs or steps of the ladder?

In DNA, a purine must always pair with a pyrimidine and vice versa in order to ensure that

___ is the genetic material for all cellular organisms and some viruses.

In Griffith's experiments,

You are asked to give a classroom demonstration of DNA supercoiling.To do so, you take two different colored pieces of rubber tubing, twist them very tightly and excessively around each other and join the ends of the tubing appropriately.Next, you relieve the supercoiling by breaking one strand and unwinding it.In this demonstration, the breaking and unwinding to relieve the supercoiling simulates the action of