Answer: Option B.
Explanation:
The first experiment of the passage shows that treatment with TGFBR1 and TGFBR2 antagonists led to lower levels of epithelial cell production. For this conclusion to be strongly valid, we want to show a positive correlation between TGFBR activity and epithelial proliferation.
Options for the question are not given. They are as follows:
a. arg or lys
b. ala
c. thr
d. leu or ser
e. Only termination codons
Answer:
d. leu or ser
Explanation:
Four codons code for proline amino acid. These are CCT, CCC, CCA, and CCG. Hydroxylamine causes C to change into T or G to change into A.
If first position is changed in each codon:
CCT = TCT (UCU)
CCC = TCC (UCC)
CCA = TCA (UCA)
CCG = TCG (UCG)
These codons produce Serine amino acid.
If second position is changed in each codon:
CCT = CTT (CUU)
CCC = CTC (CUC)
CCA = CTA (CUA)
CCG = CTG (CUG)
These codons produce Leucine amino acid.
Hence, out of the given options, option d. leu or ser is correct.
