Genetics
Unit 3
Heredity (16 Days)
Enduring Understanding: Mutations within the genetic code are one way genetic variation within members of a species can occur. Differences in how reproduction occurs between prokaryotic and eukaryotic organisms can also result in genetic variation. Mendelian genetics provides the basis for understanding the inheritance of traits. Inheritance patterns among living organisms are often more complex than simple Mendelian genetics.Essential Questions
What are different ways in which changes can occur in the genetic code? (2 days)
What are several processes in which prokaryotic cells can increase genetic variation? (1 day)
What are several processes in which eukaryotic organisms can increase genetic variation? (2 days) / SC.912.L.15.15: Describe how mutation and genetic recombination increase genetic variation
· Students will describe what a mutation is in terms of a change to the genetic code.
· Students will explain the effects of different types of point mutations (base-pair substitution, base-pair insertion, base-pair deletion) on the genetic code.
· Students will explain the effects of a missense and a nonsense mutation.
· Students will describe the roles of transformation, transduction and conjugation in creating genetic variation in bacteria.
· Students will demonstrate how the process of crossing-over during prophase I of meiosis increases genetic variation.
· Students will demonstrate how independent assortment of chromosomes during meiosis I increases genetic variation.
· Students will describe how the process of sexual reproduction increases genetic variation within a species.
Essential Questions
How did Mendel carry out his plant breeding experiments? (1 day)
What are the uses of a Punnett square? (2 days)
What are Mendel’s three Laws (Principles) of Genetics? (3 days) / SC.912.L.16.1: Use Mendel's laws of segregation and independent assortment to analyze patterns of inheritance.
· Students will describe Mendel’s plant breeding experiments.
· Also address SC.912.N.1.2: Describe and explain what constitutes science and its methods.
· Students will describe the following terms: genotype, phenotype, dominant, recessive.
· Students will explain the functions of a Punnett square.
· Students will explain how laws of probability can be used to predict the results of genetic crosses.
· Students will explain Mendel’s Law of Dominance.
· Students will explain Mendel’s Law of Segregation through a monohybrid cross.
· Students will explain the function of a test cross.
· Students will explain Mendel’s Law of Independent Assortment through a dihybrid cross.
· Also address SC.912.N.3.5: Describe the function of models in science, and identify the wide range of models used in science.
Essential Questions
Do the allele frequencies of certain dominant and recessive traits influence how they are inherited? (1 day)
How are codominance and incomplete dominance different from simple Mendelian inheritance? (1 day)
What are sex-linked traits? (1 day)
What is the difference between inheritance involving multiple alleles and polygenic inheritance? (1 day)
What is the difference between pleiotropy and epistasis? (1 day)
What are the functions of a pedigree chart? (1 day) / SC.912.L.16.2: Discuss observed inheritance patterns caused by various modes of inheritance, including dominant, recessive, codominant, sex-linked, polygenic, and multiple alleles.
· Students will describe how dominant alleles may not be the most common in a population (polydactylism).
· Students will explain how some disorders may be due to dominant alleles and how they are inherited.
· Students will describe the role of carriers in the production of recessive disorders.
· Students will explain codominance (AB blood type, roan cattle).
· Students will explain incomplete dominance (snapdragons).
· Students will explain the inheritance of sex-linked traits (hemophilia, color-blindness)
· Students will explain how multiple alleles affect inheritance (ABO blood type).
· Students will describe how polygenic inheritance can result in a continuum of phenotypes (skin color, height).
· Students will explain how a gene may have multiple phenotypic effects (pleiotropy).
· Students will explain how one gene may affect the expression of another (epistasis).
· Students will be able to identify inheritance patterns through the use of a pedigree chart.