AP Biology · Unit 5: Heredity
5.3 Mendelian Genetics
In short
You must understand how Mendel's laws of segregation and independent assortment apply to genes on different chromosomes. You need to know that fertilization restores the diploid number and increases genetic variation by creating new allele combinations. The topic requires you to apply the rules of probability to single-gene traits and use monohybrid, dihybrid, and test crosses to determine if alleles are dominant or recessive.
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What else do you need to know about Mendelian Genetics?
You must distinguish between an organism's genotype (homozygous or heterozygous) and its phenotype. You are expected to predict patterns of inheritance (autosomal, genetically linked, sex-linked) and allele dominance from data, including pedigrees, and use Punnett squares to predict genotypes and phenotypes of parents and offspring.
Can you do these?
- I can use rules of probability, Punnett squares, and pedigrees to analyze single-gene traits, determine allele dominance, and predict genotypes and phenotypes.
How is Mendelian Genetics tested on the exam?
You are expected to calculate genotypic and phenotypic ratios, and must be careful not to confuse the two, which is a common you error on the exam. You will also need to perform chi-square hypothesis testing (Skill 5.C) and predict the causes or effects of changes in biological systems (Skill 6.E). A frequent pitfall on the exam is failing to correctly identify the null hypothesis (often confusing it with an alternate hypothesis) or struggling with when to reject or fail to reject the null hypothesis. You should be prepared to calculate a chi-square value and explain its meaning in the context of a genetics scenario, such as a dihybrid cross.
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Mendelian Genetics: common questions
What do you need to know about Mendelian Genetics for AP Biology?
You must understand how Mendel's laws of segregation and independent assortment apply to genes on different chromosomes. You need to know that fertilization restores the diploid number and increases genetic variation by creating new allele combinations. The topic requires you to apply the rules of probability to single-gene traits and use monohybrid, dihybrid, and test crosses to determine if alleles are dominant or recessive.
How is Mendelian Genetics tested on the AP Biology exam?
You are expected to calculate genotypic and phenotypic ratios, and must be careful not to confuse the two, which is a common you error on the exam. You will also need to perform chi-square hypothesis testing (Skill 5.C) and predict the causes or effects of changes in biological systems (Skill 6.E).
How do I know I have mastered Mendelian Genetics?
Check you can do each of these: use rules of probability, Punnett squares, and pedigrees to analyze single-gene traits, determine allele dominance, and predict genotypes and phenotypes.
Where does Mendelian Genetics fit in AP Biology?
Mendelian Genetics is topic 5.3 in Unit 5: Heredity of AP Biology.
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