Web Class on DNA, Genome, and Inheritance

Introduction

• Today's class covers DNA, the genome, and inheritance.
• Participants from various locations.

Objectives

• Describe DNA structure as a polymer.
• Define the genome.
• Discuss the importance of understanding the human genome.
• Explain the role of alleles, genotypes, phenotypes, and inheritance of characteristics.

Background of Instructor

• Philippa, lead GCSE Biology teacher with a BSc in Animal Science and PGCE in Biology and Games.
• Over 25 years of teaching experience.

Key Topics

DNA and Its Structure

• DNA is a polymer known as deoxyribonucleic acid (DNA).
• Double helix structure discovered by Watson and Crick.
• Made up of nucleotides: deoxyribose sugar, phosphate, and nitrogenous bases (adenine, thymine, cytosine, guanine).
• One gene codes for one protein.

Chromosomes and Genes

• Humans have 46 chromosomes.
• Chromosomes consist of DNA, which is organized into genes.

Human Genome Project

• The human genome is the entire genetic material of an organism.
• Benefits include:
  • Identifying genetic disorders
  • Personalized medicines
  • Tracing human evolutionary history and migration patterns
  • Genetic counseling

Genetic Inheritance

• Genetic material inherited from parents (50/50 split).
• Gametes: sperm and egg cells with 23 chromosomes each.
• Terms:
  • Haploid: half the normal number of chromosomes (gametes)
  • Diploid: full set of chromosomes (body cells)

Alleles

• Different forms of a gene.
• Examples: eye color, hair color.
• Dominant alleles are expressed if present; recessive alleles require two copies to be expressed.
• Genotype vs. Phenotype
  • Genotype: genetic makeup
  • Phenotype: observable characteristics

Genotype Examples

• Homozygous dominant (BB)
• Homozygous recessive (bb)
• Heterozygous (Bb)

Exam Questions

• Identify genotype and phenotype from genetic scenarios.
• Explain concepts like alleles and recessive traits.

Final Thoughts

• Understanding DNA and the genome is crucial for advancements in medical science and understanding human biology.
• Encouragement to review materials as necessary.