Question

9. What is an anticodon? Where are anticodons located?

10. What type of bond links amino acids together?

11. What is mRNA processing? What are the three steps?

12. What is a gene?

13. What is a point or substitution mutation?

14. What is a frameshift mutation? What are the two types?

15. Why do most mutations have no effect on the organism?

Answer 1

9. Anticodon is present in tRNA and is a sequence of 3 bases that is complementary to the codons present in mRNA.

Anticodons are located in the tRNA.

10. Peptide bond links amino acids together.

11. mRNA processing invoves modification of RNA primary transcripts, including splicing out of introns, joining together of exons and adding a cap and tail.

The 3 steps in mRNA processing are:

i. Capping (7 methylguanisine)
ii. Splicing (introns disintegrated, extrons joined)
iii. Polyadenylation (Poly A tail)

12.  Gene is a unit of heredity and represents a segment of DNA on a chromosome that codes for a specific trait.

13. A point mutation is a mutation that only affects a single nucleotide of nucleic acid.

Point mutations most commonly involving the exchange of one base for another is called substitution mutation.

14. Frameshift mutations are additions or deletions of a nucleotide that cause a shift in the grouping of codons.

There are two types of frame shift mutations: insertions and deletions.

15. Mutations may not have any noticeable effect on the organism because of the following conditions:

i. mutation occurs in a stretch of DNA with no function

ii. mutation occurs in a protein-coding region, but ends up not affecting the amino acid sequence of the protein (silent mutation)