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3.4 Inheritance

IB Syllabus Statements

Understandings:

  • Mendel discovered the principles of inheritance with experiments in which large numbers of pea plants were crossed.

  • Gametes are haploid so contain only one allele of each gene.

  • The two alleles of each gene separate into different haploid daughter nuclei during meiosis.

  • Fusion of gametes results in diploid zygotes with two alleles of each gene that may be the same allele or different alleles.

  • Dominant alleles mask the effects of recessive alleles but co-dominant alleles have joint effects.

  • Many genetic diseases in humans are due to recessive alleles of autosomal genes, although some genetic diseases are due to dominant or co-dominant alleles.

  • Some genetic diseases are sex-linked. The pattern of inheritance is different with sex-linked genes due to their location on sex chromosomes.

  • Many genetic diseases have been identified in humans but most are very rare.

  • Radiation and mutagenic chemicals increase the mutation rate and can cause genetic diseases and cancer.

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Applications and skills:

  • Application: Inheritance of ABO blood groups.

  • Application: Red-green colour blindness and hemophilia as examples of sex- linked inheritance.

  • Application: Inheritance of cystic fibrosis and Huntington’s disease.

  • Application: Consequences of radiation after nuclear bombing of Hiroshima and accident at Chernobyl.

  • Skill: Construction of Punnett grids for predicting the outcomes of monohybrid genetic crosses.

  • Skill: Comparison of predicted and actual outcomes of genetic crosses using real data.

  • Skill: Analysis of pedigree charts to deduce the pattern of inheritance of genetic diseases.

Videos

Genetic Crosses Introduction

Genetic Crosses - The Test Cross

Genetic Crosses - Multiple Alleles, Blood Types

Causes of mutation

Chernobyl

Genetic Crosses - Simple Monohybrid Cross

Genetic Crosses - Sex Linkage

How to Solve Pedigree Diagram Questions

Hiroshima

Mendel the Man

Cystic Fibrosis and Huntington's Disease

Flashcards

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Test

We're Hexagon-na make connections!

Topic 3.4 Inheritance HookED SOLO Hexagons

Topic 3.4 Inheritance SSaQ (Syllabus Statement as Questions)

  • Comment on the purpose of making quantitative measurements with replicates in science. *NoS

  • How did Mendel discover the principles of inheritance? What scientific processes and practices did he use to increase the reliability of his data?

  • Gametes are haploid. Explain what this means in terms of alleles and genes.

  • During meiosis, explain what happens to the two alleles of each gene.

  • Use the following terms to explain the result of the fusion of two gametes: zygote, diploid, gene, allele, same, different

  • Outline the relationship between dominant and recessive alleles and co-dominant alleles.

  • Explain how genetic diseases can be caused by recessive alleles of autosomal genes.

  • Some genetic diseases are due to dominant or co-dominant alleles. Outline what this means.

  • Explain what sex-linked genetic diseases are, using an example.

  • Outline the pattern of inheritance with sex-linked genes, using an example.

  • Comment on range and frequency of genetic diseases in humans.

  • Outline the relationship between radiation, mutagenic chemicals, mutation rate, genetic diseases and cancer.

  • Outline the inheritance of ABO blood groups.

  • Outline red-green color blindness and hemophilia as examples of sex-linked inheritance.

  • Outline the inheritance of cystic fibrosis and Huntington’s disease.

  • Outline the consequences of radiation after the nuclear bombing or Hiroshima and the accident at Chernobyl.

  • Explain how to use Punnett grids for predicting the outcomes of monohybrid genetic crosses.

  • What is the purpose of using Punnett grids for studying inheritance? How would we use actual data in conjunction with Punnett grids?

  • Explain what a pedigree chart shows.

  • Outline some tips that you would use to deduce the inheritance type in a pedigree chart.

Quizlet yourself!

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