# Genetics and Heredity
Confidence: high
Last verified: 2026-05-22
Generation: ai_assisted


## TL;DR

Genetics studies heredity — how traits pass from parents to offspring. Mendel's laws (1866): segregation (alleles separate) and independent assortment. DNA structure (Watson/Crick, 1953). Human Genome Project (completed 2003) sequenced all ~3 billion base pairs. CRISPR-Cas9 (2012) enables precise gene editing.

## Core Explanation

Mendel: pea plant experiments → dominant/recessive traits. Gene: DNA segment coding for protein. Chromosome: organized DNA (humans: 23 pairs). Mutations: changes in DNA sequence — can be harmful (disease), neutral, or beneficial (evolution). CRISPR: bacterial immune system repurposed for gene editing — Cas9 protein cuts DNA at guide RNA target. Applications: treating genetic diseases, crop improvement. Ethical concerns: human germline editing.

## Further Reading

- [The Gene: An Intimate History (Siddhartha Mukherjee)](https://www.simonandschuster.com/books/The-Gene/Siddhartha-Mukherjee/9781476733524)