HONORS DNA, mRNA, & Protein Synthesis Study Guide

Which statement best explains why DNA replication is considered "semi-conservative"?

• Only half of the original DNA is preserved

• Each new DNA molecule contains one original strand and one new strand

• The process conserves energy by reusing old strands

• The replication only occurs in half of the cell's DNA

A mutation occurs that changes the DNA sequence from ATGCTA to ATGTTA. What type of impact would this most likely have?

• No effect since both sequences code for the same amino acids

• A complete shutdown of protein synthesis

• It might change one amino acid in the protein sequence

• The DNA would be unable to replicate

What is the main functional difference between mRNA and tRNA?

• mRNA carries genetic information while tRNA transports amino acids

• mRNA stays in the nucleus while tRNA works in the cytoplasm

• mRNA is single-stranded while tRNA is double-stranded

• mRNA contains uracil while tRNA contains thymine

Why does DNA need a messenger (mRNA) to carry information to ribosomes?

• Because DNA is too fragile to move

• Because DNA is too large to exit the nuclear pores

• Because ribosomes can only read RNA

• Because DNA must stay protected in the nucleus

If a DNA strand reads TACGGA, what would be the complementary mRNA sequence?

• AUGCCU

• TACGGA

• ATGCCT

• UACGGA

Which analogy best describes the relationship between DNA and proteins?

• A cookbook and a meal

• A key and a lock

• A map and a destination

• A seed and a tree

What would happen if tRNA brought the wrong amino acids to the ribosome?

• The ribosome would reject the amino acid

• The process would stop immediately

• An incorrect protein would be made

• The mRNA would correct the mistake

How does the cell ensure DNA replication accuracy?

• By having multiple copies of DNA

• Through proofreading enzymes that check for errors

• By replicating DNA multiple times

• Through random chance

Which best explains why mutations can be beneficial?

• They always improve organism survival

• They provide genetic variety that might help adaptation

• They fix damaged DNA

• They make proteins work better

What role do the sugar and phosphate molecules play in DNA?

• They carry genetic information

• They form the backbone of the structure

• They join nucleotides together

• They determine which bases pair together