Study Notes
DNA is a molecule that carries genetic information used in growth, development, functioning, and reproduction of all living organisms.
- DNA — a molecule that contains the genetic instructions for the development and function of living things. Example: DNA is structured as a double helix.
- Gene — a segment of DNA that contains coding for a protein or a function. Example: The gene for eye color determines the pigment in the iris.
- Chromosome — a long DNA molecule with part or all of the genetic material of an organism. Example: Humans have 23 pairs of chromosomes.
- Nucleotide — the basic building block of DNA, consisting of a sugar, a phosphate group, and a nitrogenous base. Example: Adenine is a type of nucleotide base in DNA.
Exam Tips
Key Definitions to Remember
- DNA: a molecule containing genetic instructions
- Gene: a segment of DNA coding for a protein
- Chromosome: a DNA molecule with genetic material
- Nucleotide: building block of DNA
Common Confusions
- Confusing genes with chromosomes
- Misunderstanding the structure of DNA as a single strand instead of a double helix
Typical Exam Questions
- What is the structure of DNA? DNA is structured as a double helix.
- How many chromosomes do humans have? Humans have 23 pairs of chromosomes.
- What is a gene? A gene is a segment of DNA that codes for a protein or function.
What Examiners Usually Test
- Understanding of DNA structure and function
- Ability to distinguish between genes, chromosomes, and nucleotides
- Knowledge of the role of DNA in heredity