Question

To learn a bit more about the outcome of mutation, leave the “More about DNA and Genes” section and check out one of the examples in “More about Mutation” and then “The Outcome of Mutation” Pick one of the examples and explain to me what happened

Now watch a video about making and using RNA under “More about Proteins” and “Transcribe and Translate a Gene”.

This process relies on DNA and three types of RNA, under “More about RNA” and then “RNA’s role in the Central Dogma” give me a description of the following

DNA

mRNA

tRNA

rRNA

Finally, put it all together. Explore “How a firefly’s tail makes light” under “More about Proteins” and tell me, starting at the gene and ending at the chemical reaction, how does a firefly make light?

Answer 1

When a gene is damaged or changed in such a way that it alters the genetic message carried by that gene, then this is called mutation. If mutation alters a protein that plays an important role in the body, then it will disrupt normal development or can cause a medical condition. This is called genetic disorder. Example: Shar Pei dogs. This dog has a protein HAS2 (hyaluronan synthase 2), where mutation takes place. It is an enzyme that makes large molecule of hyaluronan (HA), and it is found in skin cellss. The function of HA is to make skin cells to divide, and positioned moving cells to their proper place during development and wound healing process. It also gives structural support to the skin cells by surrounding them. The HAS2 enzyme produce too much of hyaluronan (HA), consequently causing thickened skin and making cells to divide more.The extra skin form folds or wrinkles in Shar Pei dogs. So, the ultimate source of genetic variation is mutation. Mutation is considered as the first step of evolution because it creates a new DNA sequence for a particular gene, creating a new allele.

The Central Dogma explains how DNA plays an important role in genetic expression. So, DNA maintains the information to encode proteins. Replication, Transcription, and Translation are the three main processes required for all cells to maintain their genetic information and to convert the genetic information encoded in DNA into gene products. These products may be RNAs or proteins. The primary role of RNA is to convert the information stored in DNA into proteins. There are three types of RNA--mRNA, tRNA and rRNA. The genetic material (DNA) is transcribed into mRNA (RNA) which is than translated into proteins. The messnger RNA (mRNA) carries the protein blueprint to its ribosomes, where protein synthesis occured. Then, the transfer RNA (tRNA) carries the appropriate amino acids into the ribosomes which will be included in the new protein. The ribosomes themselves has large quantity of ribosomal RNA (rRNA) molecules. RNAs have the ability to act as an enzyme and such RNAs are called ribozymes. Ribozymes have roles in replication, mRNA processing, and splicing.

Fireflies are beetles which have soft body and they are so called due to their conspicuous use of bioluminescence to attract mates or prey. They have different variations in their general appearance like differences in color, shape, size, and antennae. Females of some species are similar in appearance to males and larviform females are found in many firefly species. The adults bear compound eyes and are nocturnal, but some numerous species are diurnal. This chemically produced light may be yellow light. Fireflies can emit light due to a type of chemical reaction called bioluminescence. This process occurs in lower abdomen, which is a specialized light-emitting organs. With the help of enzyme luciferase, which acted on luciferin in the presence of magnesium ions, ATP and oxygen producing light. Firefly luciferase can be used in forensics, and the enzyme has medical role particularly for detecting the presence of ATP or magnesium. All fireflies can glow as larvae.