Question 1

What is the basic structure of DNA and how is it relevant to the IB DP Biology curriculum?

Accepted Answer

DNA, or deoxyribonucleic acid, is composed of two strands forming a double helix. Each strand consists of nucleotides, which include a phosphate group, a sugar molecule (deoxyribose), and a nitrogenous base (adenine, thymine, cytosine, or guanine). In the IB DP Biology curriculum, understanding DNA's structure is crucial as it underpins genetic information storage and transmission, which are foundational concepts in genetics and molecular biology.

Question 2

How do base pairing rules facilitate DNA replication?

Accepted Answer

Base pairing rules are essential for DNA replication, where adenine pairs with thymine and cytosine pairs with guanine. During replication, the DNA double helix unwinds, and each strand serves as a template for the formation of a new complementary strand. This ensures that the genetic information is accurately copied, a key concept in the IB DP Biology syllabus under the topic of nucleic acids.

Question 3

What enzymes are involved in DNA replication and what are their functions?

Accepted Answer

Several enzymes play critical roles in DNA replication. DNA helicase unwinds the double helix, DNA polymerase synthesizes the new DNA strands by adding nucleotides to the template strand, and DNA ligase joins Okazaki fragments on the lagging strand. Understanding these enzymes is vital for IB DP Biology students as it highlights the molecular mechanisms of genetic replication.

Question 4

Why is DNA replication considered semi-conservative?

Accepted Answer

DNA replication is termed semi-conservative because each new DNA molecule consists of one original strand and one newly synthesized strand. This method of replication ensures genetic continuity across generations. In the IB DP Biology curriculum, this concept is important for understanding how genetic information is preserved and passed on during cell division.

Question 5

How do errors in DNA replication affect genetic information?

Accepted Answer

Errors during DNA replication can lead to mutations, which may alter the genetic information. Some mutations can be harmful, leading to diseases, while others might be neutral or even beneficial. In the IB DP Biology course, students explore how these mutations contribute to genetic variation and evolution, emphasizing the importance of accurate DNA replication in maintaining genetic integrity.

DNA Structure and Replication

Short Notes - DNA Structure and Replication

Study Notes & Exam Tips

DNA Structure and Replication — frequently asked questions