BIO207H5 Chapter Notes -Metaphase, Mitosis, Chromatin

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emeralddog909

28 Apr 2012

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Organisms contain genetic material that governs an individual"s characteristics and that is transferred from parent to progeny. Deoxyribonucleic acid (dna) is the genetic material of all living organisms and some viruses. Ribonucleic acid (rna) is the genetic material only of certain viruses. In prokaryote and eukaryotes, the dna is always double-stranded, whereas in viruses the genetic material may be double-or single stranded dna or rna, depending on the virus. Dna and rna are macromolecules composed of smaller building blocks called nucleotides. Each nucleotide consists of a five-carbon sugar (deoxyribose in dna, ribose in rna) to which are attached a nitrogenous base and a phosphate group. In dna, the 4 possible bases are adenine, guanine, cytosine, and thymine; in rna, the four possible bases are adenine, guanine, cytosine, and uracil. According to watson and crick"s model, the dna molecule consists of two polynucleotide (polymers of nucleotides) chains joined by hydrogen bonds between pairs of bases: adenine (a) and thymine (t),

Related Questions

A virus contains 14% adenine, 36% cytosine, 35% guanine and 15%uracil. Is the genetic material in this virus double -stranded DNA,single -stranded DNA, double stranded RNA or single stranded RNA?Explain the reasoning that supports your answer.

erinskunk64

1. Unlike DNA, RNA contains

deoxyribose

a double strand

phosphates

uracil

Nucleic acid structure

2. In transcription, uracil will bond with:

thymine

cytosine

adenine

guanine

Transcription

3. The first team of scientist to document the structure of DNA was:

Franklin and Wilkins

Watson and Crick

Pauling and Chargoff

None of the above

DNA structure

4. Organelles that synthesize protein are:

lysosomes

ribosomes

endoplasmic reticulum

golgi bodies

5. Most of the time in a cell's life, it's DNA is in the form of:

Chromatin

Chromatids

Replicated chromosomes

Spindle fibers

6. Uracil is a nitrogen base that pairs with adenine. Using this information, one could conclude that uracil is a:

Purine

Pyrimidine

Neither a purine or pyrimidine

Not enough information

7. a nucleotide does not consist of a:

polymerase

5-carbon sugar

phosphate group

nitrogen base

8. The genetic code in DNA of an individual depends on the sequence (order) of:

nucleotides

purines only

phosphates

sugars

9. Before a cell divides, it must duplicate its DNA in a process known as:

translation

transformation

transcription

replication

10. The basic unit (building block) of a protein is a (an):

carbohydrate

amino acid

lipid

hydrogen bond

11. Unlike DNA, RNA contains:

deoxyribose

a double strand

phosphates

uracil

12. The structure of DNA was first documented in:

1945

1953

1956

1962

13. In DNA replication, the new molecules produced are:

of unequal length

both assembled in the same direction

built with purines as the backbone

assembled in opposite directions

DNA replication

14. The "backbone" of DNA is composed of:

ribose and phosphates

deoxyribose and phosphates

ribose and uracil

deoxyribose and thymine

DNA structure

15. RNA differs from DNA in which of the following ways?

RNA is single-stranded

RNA contains ribose

RNA does not contain thymine

All of the above

DNA structure

16. Which of the following is NOT required for the transcription process itself?

RNA polymerase

DNA

uracil-containing nucleotides

ribosomes

skyhamster121

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.