BIOL 1201 Chapter : DNA

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azuremammoth471

15 Mar 2019

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Document Summary

10 yrs ago the first person sequenced all of the nucleotides within his genome. Helped discover mutations, looked at sequence of nucleotides: nucleotide structure: 3 parts. Phosphate group- will eventually interact with carbon on pentose sugar to connect. Nitrogenous base (1 of 4)- depending on which base is found here, you will get a, g, t: the 4 nucleotides. G- guanine: structure of nucleotide strand. 5 prime to 3 prime- numbering of carbons within the structure- how dna is read. Directionality is important- dna is read by enzymes in one specific direction. When going from single stranded to double stranded dna, must read in opposite direction: base pairing in dna. Double stranded pairing (ds dna) stronger bond) Chargaff"s rule: a pairs with t (2 hydrogen bonds); g pairs with c (3 hydrogen bonds- Hydrogen bonding between nucleotides- weak electrostatic bonds: watson-crick model of dna. Complementary base pairs hold the two together.

Related Questions

QUESTION 1. Compared to eukaryotic genomes, only prokaryotic genomes:

A. contain DNA organized by histones.

B. contain usually one, circular chromosome.

C. contain plasmid DNA.

D. have chromosomes contained in a nucleus.

QUESTION 2. Azathioprine is a drug that may be prescribed to transplant recipients to reduce the chance of tissue rejection reactions. In its active state, it acts as a purine analogue, inhibiting DNA biosynthesis. This means that 6-mercaptopurine will be inserted in place of a purine containing nucleotides during DNA replication. Given this drug's mode of action, you would expect it to be incorporated into DNA in place of:

A. nucleotides containing guanine or cytosine.

B. nucleotides containing adenine or thymine.

C nucleotides containing adenine or guanine.

D. nucleotides containing guanine nucleotide or uracil.

QUESTION 3. RNA is distinguished from DNA because only RNA:

A. typically exists as a single-stranded molecule.

B. has a 3' to 5' directionality.

C. is composed of nucleotides that contain the sugar deoxyribose.

D. is composed of nucleotides that contain the nitrogen bases T, C, G, and A.

QUESTION 4. How are RNA nucleotides different from DNA nucleotides? To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.

A. RNA nucleotides do not contain thymine.

B. RNA nucleotides use the sugar ribose, while DNA nucleotides do not.

C. RNA nucleotides lack phosphate.

D. RNA nucleotides incorporate pyrimidine nitrogen bases, while DNA nucleotides only incorporate purine nitrogen bases.

The term replication refers to DNA's abilityto

a. attack bacteriaphages

b. make copies of itself

c. respond to X-ray photography

d. twist into a helix

Meselson and Stahl performed thedensity-gradient centrifugation of DNA in a solution of calciumchloride.

a. True

b. False