•there are approximately 3,000,000,000 base pairs in the mammalian genome (genes constitute only a small portion of this total)
• there are approximately 10,000 genes in the mammalian genome
• a single gene averages about 10,000 base pairs in size

questions
1. based on the assumptions above, in the mammalian genome, how many total base pairs are in all the mammalian genes?

2. what percentage (%) of the total genome does this represent?

3. what is the chance (%) that a random mutation will occur in any given gene?

4. only 1 out of 3 mutations that occur in a gene result in a change to the protein structure. what is the probability that a random mutation will change the structure of a protein?

3,000,000,000 base pairs

10,000 genes

10,000 base pairs per gene

1) number of base pairs are in all the mammalian =

= number base pares in each gene*number of genes

=10,000 *10,000=1,000,000,000

2) 1,000,000,000 is 1/3 of 3,000,000,000

because 1,000,000,000/3,000,000,000 = 1/3

which is about 0.33

which is the same as 33/100

which means it is 33%

3) A random mutation has 33% probability to occur in a gene (the same as the proportion bp gene/bp genome as asked in 2))

4) You have to multiply both probabilities: 1/3*1/3=1/9 = 0.11 = 11/100 = 11%

Base pairs are the fundamental units, which are found in the double stranded DNA. Approximately mammalian genomes have 3,000,000,000 base pairs, out of which only few percent of the genes are present.

Now, the base pairs are the nitrogenous bases, that forms hydrogen bonds to provide double-helical structure. According to the information given:

Based on the data:

1. Number of basepairs (bp) in all the mammalian = number of bp in each gene x number of genes = 10,000 x 10,000 = 1,000,000,000

2. 1,000,000,000 is of 3,000,000,000, which will be equivalent to =  33%

3. Similarly, a random mutation has 33% of chance to occur in the genetic sequence. The proportion will be 33 %.

4. The probability of random mutation =   x 0.11 or 11%.

To know more about basepairs, refer to the following link:

link

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.