Question

6. If tall and chubby is dominant over short and thin, a person who is heterozygous for tall and chubby have children with someone who is heterozygous for tall and homozygous for thin, what percentage of children will be short and chubby? 7. what is the function of PCR? If the DNA is copied for 24 cycles, how many copies of DNA will be produced? (please use a calculator) 8. how does gel electrophoresis determine the size of the DNA? Will a bigger piece of DNA travel faster or slower on the gel? (we didn't spend a lot of time talking about gel electrophoresis, but you may google it and read a little about it, it will help for next week) 9. If a DNA looks like AAGGCCTTAAGGTCT, how will the opposite strand look like? 10. what is the function of DNA polymerase?

Answer 1

6. Given tall (T) and chubby (C) is dominant over short (t) and thin (c).

Parent 1 is heterozygous for both tall and chubby I.e., with genotype TtCc.

Parent 2 is heterozygous for tall and homozygous for thin I.e., with genotype Ttcc.

So percentage of children with short and chubby I.e., with genotype ttCc is

Parents: TtCc X Ttcc

Gametes: TC Tc tC tc Tc tc

So % of ttCc is 1/8.

7. PCR (Ploymerase Chain Reaction) is a technique to produce multiple copies of a DNA segment in a precise manner. The copies of DNA produced are used for several other purposes like sequencing, gel electrophoresis, cloning into a suitable vector.

The number or copies of DNA produced after 24 cycles of PCR is 2²⁴= 16777216.

8. Gel electrophoresis is a technique used to separate DNA fragments (or other macromolecules, such as RNA and proteins) on the basis of their size and charge. Through electrophoresis, we can visualize DNA fragments of different sizes those are present in a sample and how large they are relative to one another. We can also identify the absolute size of a DNA fragment by comraing to a standard ladder made up of DNA fragments of known sizes.

A bigger piece DNA will travel slower in a gel due to their large size in comparison to the smaller piece of DNA.

9. Given one strand of DNA is AAGGCCTTAAGGTCT. So it's complementary strand is TTCCGGAATTCCAGA.

10. DNA polymerase is the enzyme used to replicate the DNA strands by utilizing deoxyribonucleotides during the process of DNA replication.