ED Compendium for web

How do living things pass traits to their offspring?

Learning Targets

Learning Experiences

Learning Targets

Learning Experiences

101 I can distinguish modes of inheritance by comparing parental and offspring traits and ratios. (11, 11c) 102 I can apply concepts of inheritance to explain patterns seen in pedigrees, offspring ratios, and trait prevalence in a population. (11, 11c)

103 I can analyze data to find inheritance patterns and explain those patterns in terms of incomplete dominance, co-dominance, multi-allelic, and polygenic traits. (11, 11b)

When shown offspring ratios from a cross, students assess the likely parental genotypes and support their claim using evidence from a Punnett square. After reviewing resources that describe pedigree nomenclature and symbols, students analyze case studies to construct multi-generation pedigrees that visually represent the segregation of specific traits or disorders. The pedigrees are analyzed to identify the patterns of inheritance for these traits/disorders (autosomal dominant and recessive as well as sex-linked and mitochondrial patterns). Students use a provided or constructed pedigree to calculate the likelihood a specific member of the pedigree will inherit a given trait/disease. Students test this claim using lab-based or simulated technologies to analyze the individual’s genetic sequence at the gene of interest. Students compare and contrast pedigrees of affected individuals who have dominant disorders caused by inherited mutations versus a de novo mutation in the germline of a parent.

Students examine genetic crosses that do not fit traditional Mendelian inheritance patterns: • A snapdragon plant with red flowers is crossed to a snapdragon with white flowers. The resulting offspring all have pink flowers. (incomplete dominance) • An individual with Type A blood has a child with an individual who has Type B blood. The child has Type AB blood. (codominance) • A rabbit with the chinchilla fur pattern is mated to a rabbit with the Himalayan fur pattern. 50% of the offspring are chinchilla, 25% are Himalayan, and 25% are albino. (multiple alleles) • A Caucasian man marries a Jamaican woman and they have five children with hair and skin tones that range from red hair and fair skin to black hair and caramel skin. (polygenic alleles) Students must use these results to develop additional models that explain how the allele combinations interact to produce the observed phenotypes. Where possible, Punnett squares should be used to help predict offspring outcomes.

Teacher Resources

Teacher Tip The ASIM blood typing lab illustrates blood compatibility, but does

Blood Typing — Alabama Science in Motion I8aBlood Students will apply their knowledge of codominance and incomplete dominance inheritance patterns by using a simulated blood typing kit. Students will determine the blood types of four samples then answer questions related to the genetics of blood types based on the results obtained during the activity. bit.ly/AMSTI-ASIM WebLab — Education Development Center Online interactive lab that explains and gives examples of incomplete and codominance with built in questions/answers. bit.ly/web-lab-directory

Alkaptonuria Alabama Science in Motion P2Alkap Students will analyze and interpret data from pedigrees of a genetic disorder to explain patterns of inheritance based on genetic factors. bit.ly/AMSTI-ASIM

not bring the genetic components in focus. Without additional effort to bring the genetic component of blood types to the forefront, this lab will not meet the learning target. Students use Punnett examples to explain blood type inheritance patterns.

HNPCC HudsonAlpha Institute for Biotechnology

HNPCC allows students to analyze and interpret data from a hereditary colon cancer scenario. Students develop a pedigree of a given family to determine the probability of expressed traits. Available from Alabama Science in Motion D8Cancer.

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A Field Guide to the Alabama Standards

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