7 2 Complex Patterns of Inheritance The student

7. 2 Complex Patterns of Inheritance Phenotype is affected by many different factors. TEKS

7. 2 Complex Patterns of Inheritance TEKS 6 F Phenotype can depend on interactions

7. 2 Complex Patterns of Inheritance One example of incomplete dominance is the four-o’clock

7. 2 Complex Patterns of Inheritance TEKS 6 F • Codominant alleles will both

7. 2 Complex Patterns of Inheritance TEKS 6 F Many genes may interact to

7. 2 Complex Patterns of Inheritance • An epistatic gene can interfere with other

7. 2 Complex Patterns of Inheritance The environment interacts with genotype. • Phenotype is

7. 2 Complex Patterns of Inheritance TEKS 6 F

Slides: 10

Download presentation

7. 2 Complex Patterns of Inheritance The student is expected to: 6 F predict possible outcomes of various genetic combinations such as monohybrid crosses, dihybrid crosses and non-Mendelian inheritance TEKS 6 F

7. 2 Complex Patterns of Inheritance Phenotype is affected by many different factors. TEKS 6 F

7. 2 Complex Patterns of Inheritance TEKS 6 F Phenotype can depend on interactions of alleles. • In incomplete dominance, neither allele is completely dominant nor completely recessive. – Heterozygous phenotype is intermediate between the two homozygous phenotypes – Homozygous parental phenotypes not seen in F 1 offspring

7. 2 Complex Patterns of Inheritance One example of incomplete dominance is the four-o’clock plant. • When plants that are homozygous for red flowers are crossed with plants that are homozygous for white flowers, the offspring have pink flowers. • The pink color is a third, distinct phenotype. • Neither of the original phenotypes of the plants in the parent’s generation can be seen separately in the F 1 generation offspring. TEKS 6 F

7. 2 Complex Patterns of Inheritance TEKS 6 F • Codominant alleles will both be completely expressed. – Codominant alleles are neither dominant nor recessive. – The ABO blood types result from codominant alleles. • Many genes have more than two alleles.

7. 2 Complex Patterns of Inheritance TEKS 6 F Many genes may interact to produce one trait. • Polygenic traits are produced by two or more genes. Order of dominance: brown > green > blue.

7. 2 Complex Patterns of Inheritance • An epistatic gene can interfere with other genes. TEKS 6 F

7. 2 Complex Patterns of Inheritance The environment interacts with genotype. • Phenotype is a combination of genotype and environment. • The sex of sea turtles depends on both genes and the environment • Height is an example of a phenotype strongly affected by the environment. TEKS 6 F

7. 2 Complex Patterns of Inheritance TEKS 6 F