May 21, 2013
Please temme the answers of these Gate questions
Match the following:
a- cell line 1- can grow in suspension culture
b- Hela cells 2- undergoes senescence and death
c- CHO cells 3- can grow indefinitely in culture
d- Primary cells 4- Needs solid surface for growth
a-1, b-3, c-4, d-2
But both Hela cells and cell line(depends on which cell line)can grow indefinitely in a culture.
iam not very sure about the answer i have given.
Q-cDNA made from the mRNA of an organism was used to make a cDNA libraryin a vector that allows the expression as a fusion with a reporter tag. What percentage of the cDNA clones is likely to give rise to correct gene products??
a- 10%
b-30%
c-50%
d-100%
Q- The double stranded DNA molecule of a virus was found by electron microscopy to have a length of 34micrometer.
a-How many nucleotide pairs are there in one molecule?
How many complete turns of the two polynucleoyide chains are present in such a double helix?
Ans. 1- 100000 molecules
Ans. 2- 5000 turns
Can u please temme how u got these answers??
10 nucleotide pairs ----> 34 angstrom -----> 1 turn (relation 1) Imp relation ***
rise per residue = 3.4 angstrom
length = rise per residue X no. of residues
34 X 10^ -6 = 3.4 X 10^-10 X no of residues
no. of residues = 10^5 nucleotide pairs
b> Using relation 1
1 turn -----> 10 nucleotide pairs
x turns -----> 10^5 nucleotide pairs
Therefore no. of turns is 10^4
Also note that 1 nucleotide pair has a MW of 618.
Q-The dissolved oxygen concentration measured by DO2 probe in a sodium sulfite solution will be??
a- 0
b- low
c- high
d- variable