Bio 156 Exam 4 chapter 25

Which factors or combinations of factors in Griffith's experiments proved lethal to mice?

heat killed S strain bacteria and live R strain bacteria S strain bacteria

The enzyme that unwinds the DNA double helix so that replication can occur is called DNA .

helicase

The chemical bond indicated by the red arrow in this figure is called a(n) bond.

hydrogen

The two strands of a DNA double helix are held together by

hydrogen bonds.

The enzyme that incorporates Okazaki fragments into the lagging DNA nucleotide strand during DNA replication is called DNA .

ligase

DNA is composed of units called , each of which contains a phosphate group, a 5-carbon sugar, and one of 4 nitrogen-containing bases.

nucleotides

The DNA component indicated by the arrow is a . Listen to the complete question

phosphate

The enzyme that assists with complementary base pairing and adding new nucleotides to the growing strand during DNA replication is DNA .

polymerase

Hershey and Chase used radioactive sulfur in order to label during the experiments that demonstrated that DNA was the genetic material.

protein

By using various enzymes to degrade candidates for the genetic material, Avery etal. were able to eliminate and as potential candidates.

protein, RNA

Erwin Chargaff determined that the number of like guanine and adenine always equal the number of like cytosine and thymine.

purines pyrimidines

The DNA bases cytosine and thymine are smaller, single-ringed bases called .

pyrimidines

Select the findings of Erwin Chargaff regarding DNA composition.

pyrimidines = purines G=C A = T

Select the result of the Hershey and Chase experiment that demonstrated DNA to be the genetic material.

radioactive DNA is taken up by bacteria

During what cellular process do Okazaki fragments form?

replication

The production of two DNA copies from a single original DNA molecule is called DNA .

replication

DNA replication can be described as , because the resulting daughter DNA contains one parent strand and one daughter strand.

semiconservative

Which two nucleotide components bind together when DNA forms a strand?

sugar phosphate

The sides of the ladder model of DNA are - backbones.

sugar-phosphate

The DNA base indicated by the circle is (Spell out the entire name; abbreviation won't do here.)

thymine

Which of the following are components of a nucleotide?

5-carbon sugar Nitrogen-containing base Phosphate

The enzyme responsible for unwinding and unzipping the DNA strands during DNA replication is

DNA helicase.

The enzyme responsible for connecting Okazaki fragments and sealing breaks in the sugar-phosphate backbone during DNA replication is

DNA ligase.

The enzyme responsible for maintaining the complimentary natures of the DNA strands during DNA replication is

DNA polymerase.

In the 1940s, scientists had concluded that the genetic material was most likely either or .

DNA, protein

Select the enzyme(s) used by Avery et al. that prevented the transformation of R strain bacteria into virulent bacteria.

DNase

Which of the following were direct contributions of the work of James Watson and Francis Crick?

Determined that sugars and phosphates formed backbones in the DNA Discovered the double helix shape of deoxyribonucleic acid Determined that nucleotides were paired inside the double helix

Which of the following contain proper complementary DNA base pairs?

G - C A - T

The short segments of DNA that are formed on the lagging strand during replication are called fragments.

Okazaki

In Griffith's experiment, which bacterial strain underwent transformation into a lethal form by obtaining genetic material from the other?

R strain

Which scientist's X-ray diffraction data helped to demonstrate the double helix structure of DNA?

Rosalind Franklin

Why did early molecular geneticists know that the genetic material needed to be a stable molecule?

So it could be replicated accurately. So it could be passed from one generation to the next.

True or false: The DNA double helix involves two strands of nucleotides running in opposite directions.

True

Which of the following are the two new nucleotides that have been created by the company Synthorx?

XY

What structure is formed when two molecular strands wind around each other in a double spiral?

a double helix

James Watson and Francis Crick contributed greatly to our knowledge of the structure of the molecule known as .

DNA

During the 1940s, scientists considered which two molecules most likely to be genetic material?

DNA protein

Select the characteristics that researchers suspected the genetic material would have prior to the discovery that the genetic material was DNA.

accurate replication passes from one generation to the next ability to store information

Which of the following DNA bases are purines?

adenine guanine

The new synthetic nucleotides have been inserted into the E.coli bacteria to increase the number of they can produce.

amino acid

The term refers to the fact that the nucleotide strands in DNA are oriented in opposite directions.

antiparallel

The synthesis of new DNA double helix molecules from a pre-existing parent molecule is called _______.

dna replication

The two nucleotide strands in DNA wind around each other forming a shape called a(n) .

double helix

DNA replication is called semiconservative because

each new DNA is one-half formed from the original molecule.

True or false: A purine base normally pairs with a pyrimidine base.

true

Rosalind Franklin's X-ray diffraction photograph demonstrated that DNA

was a double helix.