Lecture Notes: Introduction to Genetics and DNA

Overview

• Presentation by Amoeba Sisters
• Focus on genetics, DNA, and heredity
• Use of classroom pet snake, Spike, to illustrate concepts

Classroom Experience

• First teaching experience over a decade ago
• Introduction of a classroom pet, Spike, a Texas rat snake
• Spike used as a tool to make biology concepts relevant

Student Inquiry and Heredity

• Student asked about Spike's parents and traits
• Lead into heredity unit and understanding of DNA
• Importance of knowing DNA, chromosomes, genes, and traits

Key Concepts in Genetics

Heredity

• How traits are passed from parent to offspring
• Includes reproduction, inheritance tracking, and genetic problem solving

DNA Basics

• DNA: Deoxyribonucleic acid
• Found in nearly all body cells
• Inherited from both parents
• Structure: double helix with sugar-phosphate backbone

Nucleotide Structure

• Building blocks of DNA
• Comprised of:
  • Sugar (deoxyribose)
  • Phosphate
  • Base (A, T, C, G)
• Base pairing:
  • Adenine (A) pairs with Thymine (T)
  • Cytosine (C) pairs with Guanine (G)

DNA and Traits

• DNA sequences code for traits
• Environment can affect trait expression
• DNA is more similar to parents than to other species

Genes and Proteins

• Portions of DNA make up genes
• Genes code for proteins
• Proteins play roles in:
  • Trait expression
  • Transport
  • Structure
  • Enzymatic functions
  • Bodily protection
• Some DNA is noncoding; gene regulation

Chromosomes

• DNA compacted into chromosomes
• Humans have 46 chromosomes
• Chromosomes inherited from parents (23 each)
• Sperm and egg cells contain 23 chromosomes each

Recap Summary

• Chromosomes consist of genes
• Genes made of DNA sequences
• Sequences of nucleotides determine trait coding
• Foundation for understanding heredity

Further Exploration

• Dominant and recessive traits
• Alleles and Punnett squares
• More resources in heredity playlist

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Note: Reminder from Amoeba Sisters to stay curious!