Question

  

Which of the following statements characterize a restriction enzyme?

	(a)	a nuclease
	(b)	it is a protein
	(c)	separates complement base pairs by "unzipping" the DNA helix
	(d)	identifies specific sequences of DNA
	(e)	adds nucleotides bases as complement pairs

Most restriction enzymes recognize a DNA sequences between

	(a)	2-4 base pairs
	(b)	1 -2 base pairs
	(c)	4-8 base pairs
	(d)	6-12 base pairs
	(e)	12-24 base pairs

Agarose is used in gel electrophoresis instead of polyacrylamide to separate smaller, positively charged DNA.

	(a)	True
	(b)	False

Which characteristic of eukaryotic mRNA allows for its separation from other nuclec acid molecules?

	(a)	5' end cap
	(b)	poly(A) tail
	(c)	5' UTR
	(d)	3' UTR
	(e)	specific nucleotide sequence in the coding region

A cDNA library is produced by copying mRNA which has been isolated from a eukaryotic cell. Why is mRNA used to create the cDNA instead of the eukaryote's DNA itself?

	(a)	cDNA will lack introns
	(b)	cDNA produced will be single stranded and therefore easier to copy
	(c)	cDNA will contain strong promoter and regulatory sequences
	(d)	cDNA contain dideoxy bases
	(e)	cDNA will lack exons

the process of transforming bacteria using a cDNA and then isolating the transformed cDNA. If the growing bacteria are meant for protein synthesis, what is essential?

	(a)	the plasmid contains a strong promoter
	(b)	the plasmid contains two origins of replication
	(c)	the plasmid is single stranded DNA
	(d)	the double stranded DNA and the plasmid are exposed to different restriction enzymes
	(e)	the competent cells are grown in the dark

If the nucleotide base pictured below were to be added to a growing DNA polynucleotide chain during the dideoxy method (Sanger Method), the polynucleotide chain would stop growing at this point.

	(a)	True
	(b)	False

The autoradiogram shown below represents the complement sequence of a cloned DNA fragment by dideoxy sequencing. The first five nucleotides present in the 3'-end of the fragment would be?

	(a)	T-T-C-G-A
	(b)	A-A-G-C-T
	(c)	A-G-A-T-T
	(d)	A-G-A-U-U
	(e)	C-C-C-C-T

Question 2: (1 point) The sequence of events presented in the image below, represents which biotechnological process? (a) cosmid synthesis (b) Sanger method (c) electroporation (d) PCR (e) dideoxy method

Answer 1

1) Which of the following statements characterize a restriction enzyme?

Ans: Nuclease

A restriction enzyme is a nuclease enzyme that cleaves DNA sequence at a random or specific recognition sites known as restriction sites.

2)Most restriction enzymes recognize a DNA sequence between?

Ans: C) 4-8  base pairs

restriction enzyme usually are palindromes of 4-, 6- or 8-base pairs.

3)  Agarose is used in gel electrophoresis instead of polyacrylamide to separate smaller, positively charged DNA.

Ans: True

4) Which characteristic of eukaryotic mRNA allows for its separation from other nucleic acid molecules?

Ans: poly(A) tail  

The poly-A tail is a long chain of adenine nucleotides that is added to a messenger RNA (mRNA) molecule during RNA processing to increase the stability of the molecule

5) A cDNA library is produced by copying mRNA which has been isolated from a eukaryotic cell. Why is mRNA used to create the cDNA instead of the eukaryote's DNA itself?

Ans:  cDNA will lack introns ( In eukaryotic cells the mature mRNA is spliced, hence the cDNA lack of introns and can be readily expressed in a bacterial cell.)

6) the process of transforming bacteria using a cDNA and then isolating the transformed cDNA. If the growing bacteria are meant for protein synthesis, what is essential?

Ans:  the plasmid contains a strong promoter