The intron
No explanation needed just the letter of correct answer
2. DNA in cells is damaged:
a) Millions of times a day.
b) By collisions with other molecules or by chemical accidents and radiation.
c) Not very often¸ and by radiation only.
d) a and b
3. For genes that code for proteins, which molecule conveys the information from the gene to the ribosome?
a) DNA
b) mRNA
c) tRNA
d) rRNA
4. Which of the molecules below is produced during replication?
a) mRNA
b) rRNA
c) tRNA
d) DNA
5. Why is there a difference between the synthesis of a lead strand and that of a discontinuous strand in DNA molecules?
a) The origins of replication are found only at end 5' of the molecule.
b) Helicase and protein factors act at the extremity of 5'.
c) DNA polymerases can only add new nucleotides at the extremity 3' a strand in the process of synthesis.
d) DNA ligase only works in the 3' ; direction towards 5'.
6. Which of the following statements does not apply to a codon?
a) It is made up of three nucleotides.
b) It can code for the same amino acid as another codon.
c) It only codes for a single amino acid.
d) It is found attached to the end of an ANRt molecule.
7. Which of the sequences below is an unused RNA sequence?
a) The
b) The intron
c) The exon
d) The gene
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