DNA Sequencing

What are the four chemical bases (letters) that make up the DNA alphabet, and how do they pair together?

A (Adenine) pairs with T (Thymine), and C (Cytosine) pairs with G (Guanine).

What is DNA Replication, and when does a cell need to do it?

It is the process where DNA makes an exact copy of itself (DNA →DNA). It happens when a cell needs to divide to create a brand-new cell for growth or repair (like making new skin or hair cells).

What happens during Transcription, and what specific molecule is made?

The cell unzips a specific gene in the master DNA manual and copies it into a temporary mRNA molecule (\text{DNA} \rightarrow \text{mRNA}). This happens inside the nucleus.

What letter is found in RNA (mRNA/tRNA) but is completely missing from DNA? What letter does it replace?

U (Uracil). It replaces T (Thymine).

What happens during Translation, and what is the role of tRNA?

The ribosome reads the mRNA recipe to build a protein (mRNA → Protein). tRNA acts as the delivery truck, matching its anticodon to the mRNA codon to drop off the correct amino acids. This happens at the ribosome.

If a DNA strand reads T A C, what will the transcribed mRNA strand read, and what will the matching tRNA anticodon read?

mRNA: A U G (The inverse, swapping T for U)

​tRNA: U A C (The inverse of mRNA, flipping it back to look like the original DNA but with a U)