Question

name: jonathan ramirez 12/2/2025 ckhs biology (sb1b, sb2, & sb5) unit 2 standards review 1. use the following dna sequence to make a protein. label which step is transcription and which step is translation, and complete both of those processes. you will need to use the codon chart from your teacher for translation. dna: aat ggg ata aaa gtt atg cat cga mrna: amino acids: 2. fill in the blanks on the following diagram. this process is called: this process is called: dna mrna protein 2 copies of dna this process makes a copy of dna (before the cell divides through mitosis or meiosis). it is called: trait 3. background reading: mutations are any change in dna. changing the dna could change the chain of amino acids that is the protein. mutations are not always bad. some mutations have no effect. some mutations are good and increase diversity. mutations are passed down through children through gametes. i. what is a mutation? ii. are mutations always bad? iii. how are mutations passed down to children (through what type of cell)? 4. what has happened in each of the following diagrams? hint: think about the different types of mutations (substitution, insertion, deletion). atgcatcga → atgccatcga this is an example of ____ atgcatcga → atgcatga this is an example of __ atgcatcga → atgcct cga this is an example of ____

Explanation:

Question 1

Step 1: Transcription (DNA to mRNA)

In transcription, DNA is used as a template to make mRNA. The base - pairing rule for DNA to mRNA is: A (DNA) pairs with U (mRNA), T (DNA) pairs with A (mRNA), G (DNA) pairs with C (mRNA), and C (DNA) pairs with G (mRNA).
Given the DNA sequence: AAT GGG ATA AAA GTT ATG CAT CGA

• For AAT: A→U, A→U, T→A → UUA
• For GGG: G→C, G→C, G→C → CCC
• For ATA: A→U, T→A, A→U → UAU
• For AAA: A→U, A→U, A→U → UUU
• For GTT: G→C, T→A, T→A → CAA
• For ATG: A→U, T→A, G→C → UAC
• For CAT: C→G, A→U, T→A → GUA
• For CGA: C→G, G→C, A→U → GCU

So the mRNA sequence is: UUA CCC UAU UUU CAA UAC GUA GCU

Step 2: Translation (mRNA to Amino Acids)

To translate mRNA to amino acids, we use the codon chart. Each set of three nucleotides (a codon) codes for an amino acid.

• UUA: Leucine (Leu)
• CCC: Proline (Pro)
• UAU: Tyrosine (Tyr)
• UUU: Phenylalanine (Phe)
• CAA: Glutamine (Gln)
• UAC: Tyrosine (Tyr)
• GUA: Valine (Val)
• GCU: Alanine (Ala)

The step of making mRNA from DNA is transcription, and the step of making amino acids from mRNA is translation.

• The process of DNA to mRNA is called transcription. This is because in transcription, the genetic information in DNA is transcribed (copied) into mRNA.
• The process of mRNA to protein is called translation. During translation, the information in the mRNA is used to synthesize a protein.
• The process of making 2 copies of DNA (before cell division) is called DNA replication. DNA replication is the process by which a cell makes an identical copy of its DNA.

I. A mutation is any change in the DNA sequence. This can include changes in the order of nucleotides (A, T, G, C) in the DNA molecule.
II. Mutations are not always bad. Some mutations have no effect on the organism (silent mutations), some mutations can be beneficial and increase genetic diversity, and only some mutations are harmful.
III. Mutations are passed down to children through gametes (sperm cells in males and egg cells in females). Gametes are the reproductive cells, and when fertilization occurs, the genetic material (including any mutations) in the gametes is passed on to the offspring.

Answer:

• Transcription step: mRNA sequence is UUA CCC UAU UUU CAA UAC GUA GCU (obtained from DNA sequence via transcription)
• Translation step: Amino acids are Leu, Pro, Tyr, Phe, Gln, Tyr, Val, Ala (obtained from mRNA sequence via translation)

Question 2