Amoeba Sisters - Introduction to Heredity and DNA

Introduction

• The lecture began with a personal anecdote about the lecturer's first year of teaching and the introduction of a classroom pet snake, Spike.
• The snake was used to make biology concepts relatable and relevant to students.

Heredity

• Heredity is the process of passing traits from parent to offspring.
• Traits such as patterns, size, etc., are coded in DNA.
• Environmental factors can influence traits (e.g., nutrition affecting size).
• DNA is inherited from both parents and found in nearly all body cells.
• Some species can reproduce asexually, inheriting DNA from one parent.

DNA Basics

• DNA (Deoxyribonucleic Acid) is a type of nucleic acid, part of biomolecules.
• Composed of nucleotides, each having a sugar (deoxyribose), a phosphate, and a base.
• Four bases in DNA: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G).
• Base pairing rules: A pairs with T ("apples in the tree"), and C pairs with G ("car in the garage").

DNA Structure

• DNA has a double-helix shape with nucleotides forming two strands.
• Bases pair in the middle of the strands and are held together by hydrogen bonds.
• Portions of DNA form genes which can code for proteins.

Proteins and Traits

• Proteins, coded by genes, express traits and perform multiple functions:
  • Eye color, transport, structure, enzymes, protection.
• Not all genes code for proteins; some DNA is noncoding.
• Gene regulation involves turning genes on or off.

Chromosomes

• DNA is compacted into chromosomes for cell division.
• Human cells have 46 chromosomes; sperm and egg cells have 23 each.
• Chromosomes are inherited from both parents, contributing to the genetic code.

Summary

• Chromosome → Genes → DNA → Nucleotides → Bases (code traits)
• Understanding DNA is key to understanding heredity.
• Further exploration includes dominant/recessive traits, alleles, and Punnett squares.

Conclusion

• Encouragement to explore more topics through their heredity playlist.
• Final reminder to "stay curious."