***Must Show All Work*** Next, using the following data and refer to the precedi

Question

***Must Show All Work***

Next, using the following data and refer to the preceding logic and information to calculate the total length of the human cell genome (chromosomes lined-up end-to-end as if a single molecule) then calculate the ratio of total chromosome relative to the diameter of the nucleus Given: . · · Avogadro's number-6.02 x 1025 molecules/mol 650 Daltons(g/mol or grams/mole) per average DNA base pair (bp) 34 per base pair rise per base in B-DNA) Assumptions: * Somatic cells with a diploid genome · Although 46 chromosomes exist, assume it is a single but very long chromosome molecule (that is, assume all 46 chromosomes are joined end-to-end into a single, linear chromosome) Cells lack plasmid or other extrachromosomal DNA » Experimental results: . · · cell density 7.2 X 10° cells/ml [DNAJ 4.9 X 10- g DNA per ml Measured diameter of average human cell nucleus- 1.7 m

Explanation / Answer

Given

Avogadro’s number = 6.022×1023 molecules/mole= 6.022×1023 bp/mole (here bp is molecule)

Question 3.

Mass of the Human genome

Given cell density= 7.2 106 cells/ml

i.e. 1ml=7.2 106 cells

and

[DNA]= 4.9 10-5 gDNA/ml

i.e. 1ml=4.9 10-5 gDNA

Now,

1ml=7.2 106 cells

1 cell=(1/7.2 106) ml

And 1ml weighs 4.9 10-5 gDNA

So, (1/7.2 106) ml weighs

=4.9 10-5 gDNA * (1/7.2 106)ml/cells

=6.80 10-12 gDNA/cell

[DNA] per cell (g/cell) is 6.80 10-12

It is assumed that cell is diploid and it contain 46 chromosome

So, mass of DNA is 6.80 10-12 g/cell

DNA is in chromosome and cell has 46 chromosomes

So, mass of DNA/chromosome

46 chromosome/cell=6.80 10-12 gDNA/cell

1 chromosome = 6.80 10-12 gDNA/46

                        = 1.48 10-13 g/chromosome

Avogadro’s number = 6.022×1023 molecules/mole= 6.022×1023 bp/mole (here bp is molecule)

Mass of chromosome is 1.48 10-13 g/chromosome

1g= 6.022×1023 bp

So, no. of bp in one chromosome is

=1.48 10-13 g/chromosome * 6.022×1023 bp

=8.91 1010 bp

So, 1 chromsome or DNA contains 8.91 1010 bp

Now, the average weight of a single DNA base pair (bp) is 650 daltons

So, weight of 8.91 1010 bp in Daltons

=650*8.91 1010

Question. 4 Total Length of Human genome

Total length of genome is

= 8.91 1010* 3.4 X 10-10 m

=30. 3 m= 30296.85 mm

Ratio of human genome length/diameter of nucleus

Human genome length (calculated above)=30.29 m

Ratio= 30.29/1.7 X 10-6 = 1.78. X 107

Question 5

Distance between two base pairs is 3.4 Å =(3.4 X 10-10 m)

Chromosome 1 has 2.8 X 108 bp

Length in µm =2.8 X 108 bp* 3.4 X 10-10 * 10-6 = 9.52 X 104 µm

b. Chromosome length is 10 µm

Compactness =orignallenght/measured length

=9.52 X 104 µm/10 µm

=9.52 X 103 folds or 9520 folds

Question 5

Human chromosome 22 has 48 X 106 bp (1Mbp =1 X 106)

One gene has average of 5.4 exons of 266 bp

Now, exons are present in mRNA, considering one gene give one mRNA

Total no. bp in exons =5.4*266 = 1436.4 bp

%gene present in RNA =1436.4/19000*100

                                    =7.56%

B. Total genes 700 and average length of gene is 19,000 bp =

Total bp in 700 genes =700*19000=1.33 X 107

%gene present in chromsosome=1.33 X 106/48 X 106 * 100

                                                            = 27.71%

Question 7.

Technique of isolating small pieces because smaller fragments of DNA are much easy to handle. Sequencing would be much easy if DNA is in small pieces. Also calculating total bps in genome will become easy if DNA size is smaller and also mass of fragments are easy to measure than measuring whole DNA molecule.

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