DNA Replication and Transcription Review

Which explanation is TRUE regarding the structures of DNA and RNA, and how do they related to replication and the expression of a gene? (Check all that apply)

• Replication involves copying a whole molecule to produce a double-stranded molecule of DNA. RNA is single-stranded and is transcribed from a portion of one strand of DNA to produce a protein.

• Replication involves copying a whole molecule to produce a double-stranded molecule of RNA. DNA is single-stranded and is transcribed from a portion of one strand of RNA to produce a protein.

• Replication involves copying a whole molecule to produce a double-stranded molecule of RNA. DNA is single-stranded and is transcribed from a portion of one strand of RNA to produce a protein.

• Replication involves copying a whole molecule to produce a double-stranded molecule of DNA. RNA is single-stranded and is transcribed from a portion of one strand of DNA to produce a protein.

Tags

NGSS.HS-LS1-1

Why is DNA replication necessary?

• It is very small and very complicated.

• It is in everything that is important for all living things.

• It serves as the blueprint for the genetic make-up of all living things.

• It provides organisms with the energy they need.

The enzyme pictured above is necessary for the process of DNA replication. It breaks down the hydrogen bonds found between the nucleotides that hold the two DNA strands together. Identify the enzyme.

• Single-Strand Binding Protein

• Helicase

• Endonucleus

• DNA Polymerase

Click where the replication fork(s) would be found at.

Which arrow is pointing to the original DNA strand?

Which arrow(s) is pointing to the helicase?

Which gray box would be the other 5' end?

Only one strand of DNA is used as a template each time.

• replication

• transcription

Answer explanation

Correct. During transcription, only on strand of DNA contains the information in each gene. This strand serves as the template to produce RNA

Which arrow(s) is pointing to the lagging strand?

DNA is composed of two complementary strands. This is reflected in the fact that

• the number of cytosines (C) in one strand is always double the number of guanines (G) in the other strand.

• the number of guanines (G) in one strand is always equal to the number of adenine (A) in the other strand.

• the number of thymine (T) in one strand is always double the number of cytosines (C) in the other strand.

• the number of adenines (A) in one strand is always equal to the number of thymine (T) in the other strand.