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Understanding Genetics and Inheritance Patterns

May 25, 2025

SBI3U - Biology: The Unity and Diversity of Living Things

Unit 1: Understanding Inheritance Patterns

Key Concepts

  • DNA as Universal Code: DNA is essential for transmitting hereditary information and influences an organism's characteristics with environmental factors.
  • Meiosis and Inheritance: Understanding how meiosis explains inheritance patterns and why certain patterns appear.

Overall Expectations

  • Develop scientific investigation skills, including planning, recording, and communication.
  • Evaluate recent genetic research contributions and understand social/ethical implications.
  • Investigate genetic processes, especially meiosis, and solve genetic problems.
  • Understand hereditary transmission processes and technologies.

Long-term Goals

  • Ability to efficiently use energy and resources is a major selection pressure on life.

Essential Questions

  1. How does meiosis explain inheritance patterns?
  2. Why do we see the patterns that we see?

Chapter 13 - Meiosis

  • Comparison: Sexual vs. Asexual reproduction.
  • Purpose: Importance of meiosis for genetic diversity.
  • Stages: Key events in interphase, prophase I, metaphase I, anaphase I, and II.
  • Chromosomes: Homologous vs. non-homologous pairs; significance of crossing over.
  • Variation and Inheritance: Contribution of meiosis.

Chapter 14 - Mendel and the Gene Idea

  • Vocabulary: Genes vs. Traits, dominant vs. recessive, homozygous vs. heterozygous, genotype vs. phenotype.
  • Laws: Mendel's laws of segregation and independent assortment explained through meiosis.

Chapter 15 - Chromosomal Basis of Inheritance

  • Karyotyping: Its usefulness in genetics.
  • Pedigree: Usage in genetic studies.
  • Genetic Abnormalities: Nondisjunction effects, chromosome structure changes like inversions and deletions, and terms like trisomy, monosomy, polyploidy.

Skills Development

  • Develop investigation skills: planning, recording, analyzing, interpreting, communicating.
  • Solve genetic problems using Punnett squares and probability.

Assessments

  • Genetics mini-tests on Meiosis, DNA, and Inheritance Patterns.
  • Presentations on genetic disorders focusing on inheritance, symptoms, treatment, and ethical issues.

Genetic Disorder Presentation Guidelines

  • Research and present on a genetic disorder from a provided list.
  • Focus on inheritance characteristics, symptoms, prognosis, and ethical issues.
  • Demonstrate clear communication skills using tools like cue cards and visual aids.

Key Terms

  • Genetics: Study of heredity.
  • Chromosome: DNA-containing structure in cells' nuclei.
  • Genome: Total genetic content.
  • Gene: DNA segment coding for traits.

Meiosis vs. Mitosis

  • Meiosis involves two divisions, crossing over, and results in four genetically diverse haploid cells.
  • Mitosis involves one division and results in two identical diploid cells.

Practice and Problem Sets

  • Engage with questions on inheritance patterns, single vs. multiple trait crosses, and the application of Mendel's laws to understand genetic inheritance.
  • Exercises include Punnett squares, dihybrid crosses, and chi-squared analysis for genetic hypotheses.

Variations to Dominance

  • Explore incomplete dominance, codominance, and multiple alleles through examples like blood types and genetic disorders.

Chi-Squared Analysis

  • Utilize chi-squared tests to assess hypotheses on genetic inheritance patterns and variability in observed vs. expected results.