From DNA sequence to inheritance
This lab integrates molecular genetics and classical inheritance: DNA organization, gene expression, meiosis, Mendelian prediction, mutation, and allele frequencies.
- Explain genes, alleles, loci, chromosomes, and genomes.
- Trace DNA → RNA → protein.
- Predict monohybrid inheritance with a Punnett square.
- Explain how meiosis and recombination generate variation.
- Explore how mutations can alter coding sequences.
- Use Hardy–Weinberg relationships as a population-genetics model.
Vocabulary bridge
| Term | Meaning |
|---|---|
| Gene | A functional DNA sequence that contributes to an RNA or protein product. |
| Allele | An alternative sequence form at a genetic locus. |
| Genotype | The allele combination carried by an individual at one or more loci. |
| Phenotype | Observable or measurable traits arising from genotype, environment, and their interaction. |
DNA base-pair explorer
Complementarity: A pairs with T, and C pairs with G in DNA.
Chromosome → gene → sequence
Genome: the total genetic material.
Chromosome: a long DNA molecule packaged with proteins.
Gene: a functional DNA segment whose product may be an RNA or protein.
Regulatory sequence: DNA that helps control when, where, and how strongly a gene is expressed.
Central dogma stepper
Current step
Important nuance
“DNA → RNA → protein” is a useful framework, but biology includes non-coding RNAs, RNA processing, reverse transcription in some systems, and many layers of regulation before and after transcription and translation.
Monohybrid Punnett-square lab
Predicted outcomes
Meiosis sequence
Why meiosis matters
Sources of variation
- Independent assortment of homologous chromosome pairs.
- Crossing over between homologous chromatids.
- Random combination of gametes at fertilization.
- New mutations over evolutionary time.
Coding-sequence mutation lab
Use the example DNA coding strand below. Change one base and compare translation.
Mutation types
| Type | Potential coding effect |
|---|---|
| Silent / synonymous | Codon changes but amino acid remains the same. |
| Missense | One amino acid changes. |
| Nonsense | A codon becomes a stop codon. |
| Frameshift | Insertion/deletion not in multiples of three shifts the reading frame. |
Hardy–Weinberg simulator
Expected genotype frequencies
For two alleles A and a, if p + q = 1, Hardy–Weinberg equilibrium predicts:
The model assumes a large randomly mating population with no selection, mutation, migration, or genetic drift affecting the locus.