DNA

Why do cells needed both tRNA and mRNA?

• Only tRNA bends into a shape that an carry specific amino acids

• Only mRNA can be used to repair mistakes in the DNA sequence

• The tRNA in used on the ribosomes and the mRNA is used in the nucleus

• The mRNA brings information to the nucleus for the tRNA to use

ATCAGTGAT

A codon is a sequence of three nucleotide that code for an amino acid. If the DNA sequence shown here goes through transcription and translation, how many amino acids will result from the sequence

• 5

• 4

• 2

• 3

A cell is replicating its DNA. Part of the DNA strand reads A-C-c-G-T-A-C. The new strand built off this section reads -G-G-A-A-T-G. What effect might this have when the DNA replicates in the future?

• Cells having the new DNA version will look or operate differently from cells with the original DNA.

• Only the sections of DNA without mistakes will be used in the future so the DNA strand will shorten.

• The DNA will be exactly like the original since only the original strand of DNA is used as a template

• When the new strand is used as a template the strand built from it will differ from the original DNA.