Exploring DNA and Genetic Concepts

What is the primary enzyme responsible for adding nucleotides during DNA replication?

• RNA polymerase

• DNA polymerase

• Helicase

• Ligase

Answer explanation

The primary enzyme responsible for adding nucleotides during DNA replication is DNA polymerase. It synthesizes new DNA strands by adding complementary nucleotides to the growing chain, ensuring accurate replication.

Which type of RNA carries the genetic information from DNA to the ribosome for protein synthesis?

• rRNA

• tRNA

• mRNA

• snRNA

Answer explanation

mRNA, or messenger RNA, carries the genetic information from DNA to the ribosome, where proteins are synthesized. It serves as a template for translating the genetic code into amino acids, making it essential for protein production.

Identify the mutation type: A single nucleotide change that results in a different amino acid.

• Frameshift mutation

• Substitution mutation

• Chromosomal mutation

• Silent mutation

Answer explanation

A substitution mutation involves a single nucleotide change that can lead to a different amino acid in the protein sequence. This contrasts with frameshift mutations, which alter the reading frame, and silent mutations, which do not change the amino acid.

Tags

NGSS.HS-LS3-2

What is the purpose of gel electrophoresis in DNA analysis?

• To amplify DNA sequences

• To separate DNA fragments by size

• To sequence DNA

• To mutate DNA

Answer explanation

The purpose of gel electrophoresis in DNA analysis is to separate DNA fragments by size. This technique allows researchers to visualize and analyze different lengths of DNA, which is crucial for various applications in genetics.

Which of the following is a key step in the PCR technique?

• Denaturation

• Transcription

• Translation

• Replication

Answer explanation

Denaturation is a key step in PCR where the double-stranded DNA is heated to separate it into two single strands, allowing primers to bind and initiate replication. This step is crucial for the amplification process.

Explain how a frameshift mutation can affect protein synthesis.

• It changes one amino acid in the protein.

• It causes a shift in the reading frame, potentially altering the entire protein sequence.

• It duplicates a segment of the chromosome.

• It has no effect on the protein.

Answer explanation

A frameshift mutation alters the reading frame of the genetic code, which can change every amino acid downstream of the mutation, potentially resulting in a completely different and nonfunctional protein.

Tags

NGSS.HS-LS3-2

Describe the role of tRNA in protein synthesis.

• It carries amino acids to the ribosome.

• It forms the ribosome structure.

• It transcribes DNA into RNA.

• It modifies mRNA after transcription.

Answer explanation

tRNA plays a crucial role in protein synthesis by carrying amino acids to the ribosome, where they are assembled into proteins according to the sequence specified by mRNA.

How does gel electrophoresis help in DNA fingerprinting?

• By amplifying specific DNA regions

• By comparing the band patterns of DNA fragments

• By sequencing the entire genome

• By editing specific genes

Answer explanation

Gel electrophoresis separates DNA fragments based on size, creating distinct band patterns. By comparing these patterns, scientists can identify genetic similarities and differences, which is essential for DNA fingerprinting.

Discuss the strategic importance of using PCR in genetic research.

• It allows for the rapid amplification of specific DNA sequences, facilitating detailed genetic analysis.

• It is used to directly sequence DNA.

• It is primarily used for protein synthesis.

• It is used to mutate genes.

Answer explanation

The correct choice highlights PCR's strategic importance in genetic research by enabling rapid amplification of specific DNA sequences, which is crucial for detailed genetic analysis.

Evaluate the potential benefits and risks of genetically modified food.

• Benefits include increased yield and pest resistance; risks include potential environmental impact and allergenicity.

• Benefits include faster growth; risks include no known risks.

• Benefits include better taste; risks include higher costs.

• Benefits include reduced pesticide use; risks include no risks.

Answer explanation

The correct choice highlights key benefits of genetically modified food, such as increased yield and pest resistance, while also addressing significant risks like potential environmental impact and allergenicity.

Tags

NGSS.HS-ETS1-3

NGSS.HS-LS2-6