Presentation on theme: "SPONGE 4 What is the difference between incomplete dominance and codominance? (7.2) Give an example of each."— Presentation transcript:
1 SPONGE 4What is the difference between incomplete dominance and codominance? (7.2)Give an example of each
2 In incomplete dominance, neither allele is completely dominant nor completely recessive. +=Codominant alleles will both be completely expressed.+=The flower will show both red and white
3 7.4 Human Genetics and Pedigrees Set up Cornell Notes on pg. 91Topic: 7.4 Human Genetics and PedigreesEssential Questions:Don’t forget to add it to your T.O.Contents!7.4 Human Genetics and Pedigrees2.1 Atoms, Ions, and Molecules
4 KEY CONCEPT A combination of methods is used to study human genetics.
5 Inheritance of many human traits is complex. The basic principles of genetics are the same in all sexually reproducing organisms.Inheritance of many human traits is complex.Single-gene traits are important in understanding human genetics.Ex: widow’s peakWidow’s peak
6 Females can carry sex-linked genetic disorders. Males (XY) express all of their sex linked genes.Expression of the disorder depends on which parent carries the allele and the sex of the child.XY
7 A pedigree is a chart for tracing genes in a family. Phenotypes are used to infer genotypesAutosomal genes show different patterns on a pedigree than sex-linked genes.Widow’s peakNo Widow’s peak
8 Boxes = malesCircles = femalesShaded = they show the traitWhite = does not show traitHalf shaded = carrier
9 How many females are in this family? How many carriers?How many children were in generation two?How many offspring in generation three are affected by the trait?Generation 1Generation 2Generation 3Generation 4
10 How many females are in this family? 11 How many carriers? 7 Sponge 6How many females are in this family? 11How many carriers? 7How many children were in generation two? 5How many offspring in generation three are affected by the trait? 2Generation 1Generation 2Generation 3Generation 4
11 If the phenotype is more common in males, the gene is likely sex-linked (meaning the trait is on the X chromosome). Ex: Color blindnessmalesfemales
12 Do his boys have Widow’s Peaks? Please draw a pedigree chart:Mary and Joe were married in 1912.Joe had a Widow’s Peak (Ww) which is dominant, while Mary did not have a Widow’s Peak (ww)They had two children: A son named Pete who had a Widow’s Peak and a girl named Isabel who did not have a Widow’s Peak.Pete married a woman who was homozygous for a Widow’s Peak (WW), but their daughter Isabel never married.Pete and his wife had three boys.Do his boys have Widow’s Peaks?