AP Biology
Heredity and Evolution Unit Topic 1
Heredity and Evolution
Heredity
Topical Understanding:
Reproduction occurs both asexually and sexually. Meiosis results in the production of haploid gametes
for sexual reproduction and allows for the transfer of genetic information.
Genetic information is organized into chromosomes which contributes to both the continuity and
variability of genetic information. Patterns of inheritance can be predicted using Punnett squares and
probability. The location of alleles on eukaryotic chromosomes can be determined and mapped using the
frequency of crossing over.
Changes in the structure of chromosomes as well as the inheritance of specific alleles can result in
genetic disorders, some of which can be tested for at different stages of development.
Essential/Probing Questions:
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What features of meiosis are important in sexual reproduction?
Why is meiosis important in heredity?
How is meiosis related to gametogenesis?
What are the similarities and differences between gametogenesis in animals and gametogenesis in plants?
How is genetic information organized in the eukaryotic chromosome?
How does this organization contribute to both continuity and variability in the genetic information?
How did Mendel’s work lay the foundation of modern genetics?
What are the principle patterns of inheritance?
Areas of Focus:
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Meiosis and Gametogenesis
Eukaryotic Chromosomes
Inheritance Patterns
Knowledge:
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Meiosis
o Somatic cells vs. gametes
o Homologous chromosomes: autosomes vs. sex chromosomes
o Haploid cells vs. diploid cells
o Stages of Meiosis
o Comparisons of mitosis and meiosis
o Sources of genetic variability: crossing over (chiasma, genetic recombination), independent
orientation of chromosomes, random fertilization
Alterations of chromosome number and structure
o Karyotype
o Nondisjunction: trisomy and monosomy
o Deletion, duplication, inversion, translocation
Mendel’s Principles
o Self-fertilization, cross fertilization, hybrids, P generation, F1 and F2 generation, alleles, dominant,
recessive, homozygous, heterozygous
o Punnett Squares
o Principle of Segregation
o Principle if Independent Assortment
o Test cross
o Rules of Probability: rule of multiplication, rule of addition
o Pedigree analysis and single gene autosomal disorders
C. Gay Revised 6/19/07
Steamboat Springs High School
AP Biology
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Heredity and Evolution Unit Topic 1
o Fetal analysis, amniocentesis, chorionic villus sampling, ultrasound imaging
Variations on Mendel’s Principles
o Incomplete dominance
o Multiple alleles: codominance (ABO blood groups)
o Pleiotropy
o Genetic Testing
o Epistasis
o Polygenic inheritance
Chromosomal Basis of Inheritance
o Chromosomal theory of inheritance
o Linked genes
o Recombination frequency and gene mapping
Sex Chromosomes and Sex-linked Genes
o Sex determination mechanisms in organisms (X-Y, X-O, Z-W, chromosome number, monoecious,
dioecious, hermaphroditic)
o Sex-linked inheritance and disorders
Skills:
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Calculations of genotypic and phenotypic frequencies using Punnett Squares and rules of probability
Chi-Square analysis
Gene mapping using frequencies of crossing over
C. Gay Revised 6/19/07
Steamboat Springs High School