Lab 3: Isolation of genomic DNA from onion cells estimation of DNA
21. The basic structure of a nucleotide includes
a. amino acids
b. tryptophan and leucine
c. base, sugar, and phosphate
d. mRNA, rRNA, and tRNA
22. In an analysis of the nucleotide composition of double-stranded DNA to see which bases are equivalent in concentration, which of the following would be true?
a. A = C
b. A = G and C = T
c. A + C = G + T
d. A + T = G + C
23. What is the purpose of sample homogenization during DNA extraction?
a. To precipitate DNA
b. To release the DNA
c. To denature proteins
d. To break cell wall and ensure homogeneity and an equal representation particles in the test samples
24. During DNA extraction from cell, which of the following is used for precipitating DNA?
a. SDS
b. Na-Citrate
c. Chloroform
d. Ethyl alcohol
25. What is the purpose of SDS during DNA extraction?
a. Denatures histone proteins
b. Denatures protein structure and disrupts the membranes
c. Separates DNA from histones
d. Separates DNA from lipid bilayer
26. Which of the following prevent damage to cell by help their maintain pH and osmolality during DNA extraction.
a. Chloroform
b. Phosphate buffer saline
c. Ethanol
d. EDTA
27. Na-citrate addition during DNA extraction helps in
a. deproteinization
b. membrane emulsification
c. cell wall disintegration
d. neutralizing the charge on the phosphate backbone of the DNA
28. What is the correct order of steps for DNA extraction from a cell?
a. Homogenization, Deproteinization, Precipitation
b. Deproteinization, Homogenization, Precipitation
c. Precipitation, Homogenization, Deproteinization
d. Precipitation, Deproteinization, Homogenization
29. DNA have an absorption maximum at what UV wavelength?
a. 220 nm
b. 280 nm
c. 300 nm
d. 260nm
30. Deproteinization involves
a. Alcohol
b. Na Citrate
c. Chloroform
d. EDTA