Multiple choice questions

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January 23, 2009

Multiple choice questions
(numbers in brackets indicate the number of correct answers)
Nucleic acids were first isolated in the
17th century 
18th century 
19th century 
20th century 
(1)
The following are not components of DNA
Pyridines

Purines

Sulfates

Phosphate

Deoxyribose

(2)
The DNA double helix is stabilized by
Ionic bonds

Covalent bonds

Hydrogen bonds

Hydrophobic interactions

(2)
The secondary structure of proteins is stabilized by
Hydrophobic interactions

Ionic bonds

Hydrogen bonds

Disulfide bonds

(1)
DNA is synthesized in
5’->3’ direction

3’->5’ direction

in both directions

(1)
The major form of DNA in cells is
A-DNA

B-DNA

C-DNA

Z-DNA

(1)
Z-DNA




Winds to the left
Has a wider diameter than A and B-DNA
Does not naturally occur in cells
Has been studied extensively by Watson and Crick
(1)
The genetic code
Is a “degenerate” code
Consists of 60 codons
Has three initiation codons
Specifies the 20 standard amino acids
Has four termination codons





(2)
The human nuclear genome
Is about 2 billion bp in size
Is split into 24 chromosomes
Contains about 50,000 genes
Is the largest genome known to date




(1)
RNA molecules
Contain ribose instead of deoxyribose
Are less abundant than DNA in cells
Can be processed in different ways
Are usually more than 3000 nucleotides long
Are more stable than DNA molecules
Transcriptomes
Consist of RNA
Consist of proteins
Are translated into proteins
Do not change in their composition
Differ in different cell types
Restriction endonucleases
Are located in the nucleus
Degrade DNA completely into nucleotides
Bind to DNA
Occur only in bacteria
Are proteins
Were discovered in the 1980s
DNA ligases










(2)
(3)






(3)
Catalyze the formation of ß-glycosidic bonds
Catalyze the formation of phosphodiester bonds
Play a role in the process of transcription in cells
Play a role in the process of translation in cells
Require energy to function
Are found in all living cells
Reverse transcriptases
Are DNA polymerases
Are RNA polymerases
Use DNA as template
Use RNA as template
Are viral enzymes
Are essential enzymes in all eukaryotic cells






(3)






Ribosomal RNAs
Make up ≈ 20% of all RNA in a cell
Are involved in synthesis of proteins
Are molecules that normally are not processed
Bind ribosomal proteins
(3)




Mitochondrial genomes
Are much smaller than nuclear genomes
Are not found in all cells of a multicellular organism
Are always circular
Have a very high copy number compared to nuclear genomes
(2)




(2)
Bacteriophages
Are viruses
Can infect bacteria and eukaryotic cells
Have been used by Oswald Avery to show that DNA contains genes
Have an average size of around 1 µm
Consist of proteins and nucleic acid





Agarose
Is isolated from algae
Is primarily used to separate proteins
Is normally used at concentrations around 1%
Forms pores of 10 - 30 nm in diameter in gels
(2)




(2)
Total number of correct answers: 34
If time allows, please try also to answer the “Multiple choice” and “Short answer
questions” at the end of chapters 1 and 2 of the GENOMES textbook.
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