Table of contents

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1. Introduction to Genetics51m
2. Mendel's Laws of Inheritance3h 37m
3. Extensions to Mendelian Inheritance2h 41m
4. Genetic Mapping and Linkage2h 28m
5. Genetics of Bacteria and Viruses1h 21m
6. Chromosomal Variation1h 48m
7. DNA and Chromosome Structure56m
8. DNA Replication1h 10m
9. Mitosis and Meiosis1h 34m
10. Transcription1h 0m
11. Translation58m
12. Gene Regulation in Prokaryotes1h 19m
13. Gene Regulation in Eukaryotes44m
14. Genetic Control of Development44m
15. Genomes and Genomics1h 50m
16. Transposable Elements47m
17. Mutation, Repair, and Recombination1h 6m
18. Molecular Genetic Tools19m
- Genetic Cloning
  9m
- Methods for Analyzing DNA
  9m
19. Cancer Genetics29m
- Overview of Cancer
  21m
- Cancer Mutations
  7m
20. Quantitative Genetics1h 26m
21. Population Genetics50m
- Hardy Weinberg
  19m
- Allelic Frequency Changes
  31m
22. Evolutionary Genetics29m

7. DNA and Chromosome Structure

DNA Structure

Genetics

7. DNA and Chromosome Structure

DNA Structure

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Multiple Choice

Why is DNA commonly referred to as a double-helix model?

Because it consists of two antiparallel strands twisted around each other forming a helical structure

Because the nitrogenous bases are arranged in a linear sequence

Because its sugar-phosphate backbone forms a circular loop

Because it is made up of two identical single-stranded molecules

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Verified step by step guidance

Understand the structure of DNA: DNA is composed of two long strands made up of nucleotides, which include a sugar, a phosphate group, and a nitrogenous base.

Recognize that these two strands run in opposite directions, meaning they are antiparallel. One strand runs 5' to 3', and the other runs 3' to 5'.

Know that the strands twist around each other, forming a spiral shape. This twisting is what creates the helical structure.

The nitrogenous bases from each strand pair specifically (A with T, and G with C) and are located inside the helix, while the sugar-phosphate backbones form the outside.

Putting it all together, DNA is called a double helix because it consists of two antiparallel strands twisted around each other, forming a helical (spiral) structure.