Question

How could you tell whether a given sequence was DNA or mRNA?

Was it easier to decode messages written in DNA or in mRNA sequences?
Which cellular enzymes or machines are you imitating when you "transcribe" DNA into mRNA?
Which cellular enzymes or machines are you imitating when you "translate" mRNA into a chain of amino acids?
What else needs to happen in a eukaryotic cell between the processes of transcription and translation?
In step 5, how did different mutations affect the amino acid sequence that was encoded?
Explain why some single nucleotide mutations affect an amino acid sequence and some single nucleotide mutations do not.
Explain why nucleotide insertions and deletions affect the amino acid sequence so profoundly.
Why could your secret message include only 20 of the 26 letters of the alphabet?
Did you find that it was difficult to work with only these letters?

Answer 1

1. You could tell whether a given sequence was DNA or mRNA because of Uracil and Thymine base differences in both

2. Answers may vary up to you, but messages are easier to decode written in DNA

3. You are imitating RNA polymerases.

4. You are imitating RNA polymerase once again

5. The RNA strand is delivered to start the process of translation; RNA>>Protien

6. Different mutations affect different amino acid sequences because they alter the code which makes it un-easy to decode the sequence

7. Some single nucleotide mutations affect an amino acid sequence depending on what mutation it is causing. Some single nucleotide mutations do not do this because they aren't as severe and they don't cause codons to mix up.

Answer 2

1

ADNA sequences use the nucleotides A, T, G, and C, while mRNA sequences use the nucleotides A, U, G, and C.

B It was easier to decode the messages written in mRNA sequences because these sequences could be translated directly into the amino acid sequence.

2

A The cellular enzyme that carries out transcription is RNA polymerase.

B The cellular machine that carries out translation is the ribosome, which is composed of both rRNA and ribosomal proteins.

C In a eukaryotic cell, an mRNA transcript often has additional untranslated regions and a poly-A tail. A eukaryotic mRNA transcript would need to be transported from the nucleus to the cytoplasm before it could be translated.

3

A Some amino acids are encoded by several codons. If a single nucleotide mutation still encodes for the same amino acid, the resulting amino acid sequence would not be affected. This happens most often with nucleotides in the third position of a codon.

B If a single nucleotide mutation changes the amino acid encoded, the resulting amino acid sequence would be affected. This happens most often with nucleotides in the first and second positions of a codon.

C Nucleotide insertions and deletions cause frameshift mutations, which change the reading frame of translation and will encode completely different amino acids from that point forward.

4

A There are only 20 canonical amino acids, so the letters B, J, O, U, X, and Z are not used as one-letter codes.

B It was a little difficult to not use the letters B, J, O, U, X, and Z at first, but there are messages to write without these six letters.

Step-by-step explanation: