EmSAT EmSAT Biology 6 — Questions and Answers
Question 1: What is the process of transcription in molecular biology?
- DNA → DNA (DNA replication)
- DNA → RNA (making mRNA from DNA) (Correct answer)
- RNA → Protein (making protein from mRNA)
- Protein → DNA
Correct answer: DNA → RNA (making mRNA from DNA)
Transcription is the process of making a messenger RNA (mRNA) copy of a DNA gene. It occurs in the nucleus and is the first step in gene expression.
Question 2: What is translation in protein synthesis?
- DNA → RNA
- RNA → Protein (Correct answer)
- DNA → Protein directly
- Protein → Amino acids
Correct answer: RNA → Protein
Translation is the process by which ribosomes read the mRNA sequence and assemble amino acids into a protein, following the genetic code.
Question 3: What is a codon?
- A single DNA base
- A sequence of three bases on mRNA that codes for one amino acid (Correct answer)
- A type of mutation
- An entire gene
Correct answer: A sequence of three bases on mRNA that codes for one amino acid
A codon is a sequence of three nucleotide bases on mRNA that specifies a particular amino acid (or start/stop signal). There are 64 possible codons coding for 20 amino acids.
Question 4: What is the role of tRNA in protein synthesis?
- Carries the genetic code from nucleus to ribosome
- Brings the correct amino acid to the ribosome during translation (Correct answer)
- Unzips the DNA double helix
- Synthesizes new DNA strands
Correct answer: Brings the correct amino acid to the ribosome during translation
Transfer RNA (tRNA) carries specific amino acids to the ribosome during translation. Each tRNA has an anticodon that pairs with the corresponding mRNA codon, ensuring the correct amino acid is added.
Question 5: What is the central dogma of molecular biology?
- DNA → Protein → RNA
- RNA → DNA → Protein
- DNA → RNA → Protein (Correct answer)
- Protein → RNA → DNA
Correct answer: DNA → RNA → Protein
The central dogma describes the flow of genetic information: DNA is transcribed into RNA (transcription), which is then translated into protein (translation). Information flows DNA → RNA → Protein.
Question 6: What is epigenetics?
- Changes to the DNA sequence itself
- Changes in gene expression not involving DNA sequence changes (Correct answer)
- The study of genes in populations
- Mutation caused by radiation
Correct answer: Changes in gene expression not involving DNA sequence changes
Epigenetics refers to changes in gene expression that do not involve alterations to the DNA sequence itself. These changes (e.g., DNA methylation, histone modification) can be influenced by the environment and can be heritable.
EmSAT EmSAT Biology 6
What is the process of transcription in molecular biology?