The Process of DNA Replication and Its Importance in Cell Division

DNA replication is the process by which DNA makes an identical copy of itself, crucial for cell division. It occurs during the S phase of the cell cycle, ensuring daughter cells have identical DNA. The process begins with DNA helicase unwinding the double helix and breaking hydrogen bonds. Each strand serves as a template for new strands, with DNA polymerase adding nucleotides following base pair rules. The result is two identical DNA molecules, ready for mitosis.

Why is DNA replication necessary before a cell divides?

• To create more cells

• To destroy old DNA

• To ensure each daughter cell has identical DNA

• To change the genetic code

During which phase of the cell cycle does DNA replication occur?

• S phase

• G1 phase

• G2 phase

• M phase

What is the significance of the S phase in the cell cycle?

• It is when the cell divides

• It is when the cell grows

• It is when the cell rests

• It is when DNA is synthesized

What is the role of DNA helicase in DNA replication?

• It adds nucleotides to the DNA strand

• It breaks hydrogen bonds and unwinds the DNA

• It repairs DNA mutations

• It synthesizes RNA primers

What happens to the DNA molecule at the beginning of replication?

• It is translated

• It is unwound and separated

• It is transcribed

• It is condensed

What does DNA polymerase do during DNA replication?

• It unwinds the DNA double helix

• It removes RNA primers

• It adds free nucleotides to the template strands

• It breaks down nucleotides

Which base pairs with adenine in DNA?

• Uracil

• Cytosine

• Guanine

• Thymine

What ensures the accuracy of DNA replication?

• The base pair rule

• The speed of replication

• The presence of RNA

• The number of nucleotides

Which enzyme is responsible for adding nucleotides during DNA replication?

• Ligase

• DNA polymerase

• RNA polymerase

• DNA helicase

What is the result of DNA replication?

• Two different DNA molecules

• One new and one old DNA molecule

• A single RNA molecule

• Two identical DNA molecules