If any of you guys would be able to do any of these questions or answer them would be super great!
(For the multiple choice, can you please explain why each option is wrong like in a sentence or something?)
CHAPTER 11/12: (EXAM: 2)
MULTIPLE CHOICE:
Q30 (2013)
Q23 (2015)
(I KNOW HOW TO DO IT, JUST WANT TO KNOW IF THE SEQUENCE OF AMINO ACIDS TABLE REPRESENT MRNA CODONS OR TRNA ANTI-CODONS? BECAUSE THE AMINO ACID ‘ASN’ CODES FOR “AAC” (CODON), SO WHEN YOU CONVERT IT TO DNA IT BECOMES ‘TTG’ SO IF THE TABLE REPRESENTS MRNA CODONS, ALL WE DO IS SWITCH IT BACK TO DNA, BUT HOW ABOUT IF THE TABLE REPRESENTS TRNA ANTI-CODONS?? OR IS THIS NOT POSSIBLE? IS THE TABLE OF AMINO ACIDS IS ALWAYS REPRESENTED AS MRNA CODONS??
Q11 (2011)
SHORT–ANSWER:
Q5 d (ii) (2011)
Q4 (a) (2012) (CAN YOU PLEASE DRAW THIS FOR ME)
Q6 (c) (2015) (HOW IS THAT ANSWER POSSIBLE?)
Q8 a (i) (Which of the STOP or START codons do we include when counting? Because I know that we just have to count the exons in bold?)
Q8 (iii) (2015) (Does this mean "TAC" is not to be included when counting amino acid sequence as "AAT" is the 5th CODON instead of "AAA"?)
THANKS SOOO MUCH!! and super sorry if i'm bothering you
Sure, do my best - although it may better for your learning next time to walk through your reasoning thus far
2013, MC, Q30Okay, so this is about restriction enzymes. Restriction enzymes cut at specific sequences. You'll have to look at the options given above Q29. You can see how they cut at this
image. Note how the red represents AluI and the blue represents HindIII.
2015, MC, Q23Yeah, this is a pretty confusing layout. This table refers to the RNA sequence of the
complementary strand. You'll see that we need Asn-Gly-Pro-Arg-Ser, so let's go through this systematically
Asn → AAU, AAC → TTA, TTG. This eliminates D.
Gly → GGU, GGC, GGA, GGG → CCA, CCG, CCT, CCC. This eliminates B.
The next two for A and B are identical, so let's skip to the last one, which is different.
Ser → UCU, UCA, UCC, UCG, AGU, AGC → AGT, AGT, AGG, AGC, TCA, TCG. This eliminates C.
Following this, A is the answer,
2015, SA, 6cI'm afraid I can't help here, I lost this mark, and was planning on asking this myself, haha.
2015, SA, 8aiThe answer to your question is in the stem of the question (don't worry, I have a habit of missing things too). It says "
the DNA triplet TAC indicates START and codes for the amino acid methionine that remains in the polypeptide.". It does not say that the STOP triplet stays in the polypeptide, so count the START codon and the remaining, non-STOP exons.
2015, SA, 8iiFrom what I understand, you count everything up to the mutation. Remember that STOP codons aren't included in the polypeptide, and that the possible STOP codons are - from the stem-, ATC, ATT, and ACT. By looking at the sixth triplet, AAT, you can see that a substitution mutation could occur to change it to the triplet ATT.
For the questions from 2011 and 2012, you'll have to indicate which exam it is from, as there are two exams for that year,