Questions

1. Examine the two double-stranded DNA molecules. Are they identical or different in any way? The two double-stranded DNA molecules produced by replication are identical. This is because both strands are used as template strands and the bases are complementary paired, which results in two identical double-strands of DNA molecules.

 

2. If you were asked to replicate each of the two DNA molecules on your table to create four identical DNA molecules, how would you go about doing this? To replicate the two DNA molecules I would first separate the two strands creating a replication fork, which is done by the enzyme helicase. I would then start elongating the leading strand by adding complementary bases in the 5’ to 3’ direction, this is enabled by DNA polymerase which reads the bases. When replicating the lagging strand there will be Okazaki Fragments because DNA polymerase cannot read it continuously, so there will be gaps which will be sealed by the enzyme DNA ligase. With the completion of this process there will four identical DNA molecules.

 

3. You now have two copies of a segment of the hGH gene on your table. During periods of growth and cell division, the chromosomes, which are made up of genes, must divide. What features about DNA replication causes each new DNA molecules to be exactly like the original? The feature of DNA replication that causes each DNA molecule to be exactly like the original is complementary base pairing. Due to complementary base pairing Adenine only associates with Thymine and Guanine only associates with Cytosine, therefore, the sequence of base pairs are identical in the 5’ to 3’ direction.

 

4. When this mutated DNA molecule replicates, will the resulting new DNA be similar or different from the hGH gene? Explain. When the mutated DNA molecule replicates the resulting DNA will be different from the hGH gene because it has been modified by the mutation and the mutation is located on the strand being replicated.

 

5. Draw structures of the new double-stranded mutated gene you created by using the letters A, T, C, and G in a manner similar to that shown earlier.

 

 

 

 

 

 

 

 

 

 

 

 

 

6. In your own words, explain how mutations can occur in cells and how this might affect the new organism with the mutation. Mutations can occur due to several reasons, one way is environmental factors, such as UV radiation from the sun or mistakes made during cell division. Mutations can also be obtained when there is a mutation in the genetic information contributed from the sperm or egg. Most mutations occur in regions of the cells that are non-coding, in that case that mutation will not affect the organism. If the mistake is in the coding region, protein synthesis could be altered, which can affect many processes if certain proteins aren’t being produced.