Question

1) Why does your body need to produce haploid cells?

2) Why is it important for an organism that DNA undergoes semi-conservative replication?

3) Why is gene therapy more likely to help a condition like sickle cell anemia?

4) How are ecoli bacteria used to produce insulin?

Answer 1

1. The haploid cells are produced by the process of meiosis. They have chromosome number reduced to half as compared to the parent cell as we know that humans are diploid and they reproduce sexually and if two diploid parent having diploid gamets are fused together then it will generate abnormalities in the chromosome number as the chromosome number will be doubled as compared to the parent cell. Therefore it is the prime need to reduce the chromosome number to half so as to form the diploid organism again.

2. The DNA replicate semi-conservatively that is the resulting a daughter strand which has one parental strand. As DNA is the double helical structure when it replicates then the double strand of DNA become unwound leading to formation of single strand DNA in which both the strand of DNA act as template and synthesis the complementary strands to each other. Therefore the DNA having one parental strand and one daughter strand will have more variations. This is why the DNA replicate semi-conservatively.

3. Sickle cell anemia is caused by the substitution of amino acids glutamine which is coded by the codon GAG is substituted by the amino acids valine (coded by GUG). This is the example of frame shift mutation because the reading frame of the gene is altered leading to the formation of a different protein. This could be treated by gene therapy by correcting the faulty gene which changes the protein and We can restore the amino acid sequence to it's normal State.