Heredity

Overview

Foundations of classical and molecular genetics: inheritance patterns, probability, pedigrees, DNA → RNA → protein basics.

Core Topics

• Mendelian: mono/dihybrid, test crosses, law of segregation/independent assortment
• Extensions: incomplete dominance, codominance, epistasis, multiple alleles
• Sex-linked, mitochondrial, linkage and recombination basics
• Pedigrees: autosomal dominant/recessive, X-linked, matrilineal hints
• Molecular: DNA structure, replication overview, transcription/translation basics

Calculations

• Probability rules (sum/product), binomial where applicable
• Recombination frequency (intro level if included)

Strategy

• Build pattern recognition for pedigrees
• Use probability trees and Punnett shortcuts
• Keep a concise glossary and phenotype clues

Worked examples

1. Dihybrid cross (AaBb×AaBb), probability of A−bb: P(A−)=3/4, P(bb)=1/4 → combined 3/16
2. Pedigree: unaffected parents with affected son; no affected daughters across two generations → X-linked recessive likely; verify carriers
3. Conditional probability: given first child is affected, compute probability next is unaffected under autosomal recessive

Pitfalls

• Misclassifying X-linked vs autosomal
• Ignoring penetrance/expressivity notes
• Arithmetic errors in multi-locus problems

Study Roadmap

1. Master core patterns and exceptions
2. Timed pedigree sets and crosses
3. Incorporate molecular basics and vocabulary
4. Mixed problem sets under time

Pitfalls

• Misclassifying X-linked vs autosomal
• Ignoring penetrance/expressivity notes
• Arithmetic errors in multi-locus problems

References

• SciOly Wiki: https://scioly.org/wiki/index.php/Heredity
• OpenStax Biology