In a strand of DNA, if it contains 20% of Thymine, then how much Guanine would be
present?

Explanation:

Number of Adenine = Number of Thymine

Number of Guanine = Number of Cytosine

Total number of Adenine and Thymine nucleotides = 40%

Therefore number of Guanine = 60% / 2 = 30%.

All the thymine binds with adenine, therefore there is the same number of nucleotides that contain thymine as there are of adenine

If we have 20% thymine bases there will certainly be 20% adenine

we are left with 60% that are guanine and cytosine, we know that all cytosine binds with guanine, therefore there is the same number of cytosine and guanine bases. 2G=60 G=60/2=30% guanine bases

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.