Amoeba Sisters Lecture - Introduction to DNA and Heredity

Introduction

• Anecdote about the first teaching experience
• Story of acquiring a classroom pet, a Texas rat snake named Spike
• Aim to make the classroom exciting and relevant to biology concepts

Spike the Classroom Pet

• Spike's relevance to teaching biology
  • Predation: Spike's appetite for rats
  • Mitosis: Need for Spike to make more cells
• Student question about Spike’s parents
  • Leads into the topic of heredity

Heredity Basics

• Heredity: How traits are passed from parent to offspring
• Relevant resources: Playlist on heredity including reproduction, pedigrees, Punnett squares, Mendelian and non-Mendelian inheritance

Introduction to DNA, Chromosomes, Genes, and Traits

• Traits: Characteristics like body patterns and size, coded in DNA
• DNA existence: Found in nearly all body cells
• DNA inheritance from parents
• Environmental influence on traits (e.g., nourishment affecting size)
• DNA code uniqueness

DNA Structure and Function

• DNA: Deoxyribonucleic acid, a type of nucleic acid
• DNA composition: Made of nucleotides
  • Nucleotide components: Sugar (deoxyribose), phosphate, base
  • Four bases: Adenine (A), Thymine (T), Cytosine (C), Guanine (G)
  • Base pairing: A with T ("apples in the tree"), C with G ("car in the garage")
• DNA's double-helix structure
  • Two nucleotide strands paired by bases held together by hydrogen bonds

Genes and Proteins

• DNA segments form genes
  • Genes code for proteins which express traits
• Examples: Human eye color determined by multiple genes
  • Proteins' diverse roles: Transport, structure, enzymes, protection
• Gene expression: Not all genes make proteins, some are noncoding
• Gene regulation: Turning genes on or off
  • Video resource available on gene regulation

Chromosomes

• DNA organization into chromosomes
• Human chromosome count: 46 (23 from each parent)
  • Body cells: 46 chromosomes
  • Sperm and egg cells: 23 chromosomes each

Recap

• Chromosome structure: Contains genes, which consist of DNA, made up of nucleotides
• DNA base sequence: Critical for coding traits
• Understanding these foundations is necessary for studying heredity

Further Exploration

• Future questions: Dominant and recessive traits, alleles, Punnett squares
• Check out the heredity playlist for deeper understanding

Stay curious! - Amoeba Sisters