ATI TEAS Guide To Science | DNA, RNA & Genetics Question Review

When RNA transcribes a codon from DNA during transcription, thymine is replaced with uracil. Thymine is less prone to mutation, which makes it a good storage vehicle for DNA. Uracil is more flexible, which makes it more suited to its temporary role in RNA. The other three nitrogenous bases, adenine, guanine, and cytosine, are used in both DNA and RNA.

Understanding the role of DNA is important in answering questions about it. DNA stores the genetic information necessary to create living matter and beings. Choices B, C, and D are all created by DNA and RNA. DNA itself is composed of nucleotides.

Transfer RNA, called tRNA, is needed during translation. It recognizes the specific codon in mRNA needed to create a specific amino acid. There are 64 different possible codons and 20 amino acids, so only the appropriate tRNA will unlock the code and create proteins.

Proteins are the engines of cellular, and thus life, function. In the form of enzymes, they manage the cell’s metabolic processes. DNA and RNA, through transcription and translation, build the amino acids necessary to create proteins. Without proteins, the other aspects of living material–blood, neurons, and cell walls–would not exist.

There are only a certain number of possibilities of base pairs due to the unique nature of the hydrogen bonds that hold them together. Cytosine bonds with guanine using three hydrogen bonds. Adenine and thymine require only two hydrogen bonds, as do adenine and uracil in RNA.

Base pairs combine in only a few ways because of the unique nature of the hydrogen bonds that hold them together. Cytosine bonds with guanine using three hydrogen bonds. Adenine and thymine require only two hydrogen bonds as do adenine and uracil in RNA. These base pairs are typically written using their letter symbols, G-C and A-T.

Messenger RNA, called mRNA, is created during transcription. Its function is to carry the genetic code to the ribosomes for protein formation. It holds the genetic information in three base pair sequences, called codons.

Mitochondrial DNA is inherited only from the mother in almost all organism that reproduce through sexual reproduction. Sperm cells contain mitochondrial DNA, but the egg cell’s processes destroy it.