Human Inheritance Gaiser Life Science

Know Evidence Page 43 Human Inheritance What are some traits a child may share with one or both parents? Explain your answer. After listening to the PowerPoint lecture, come back here and list evidence to explain why your answer to the above question is or is not a good answer. You may also use other outside sources to help you respond.

Clarifying ?s Information Page 44 multiple alleles - a single gene that has more than two alleles or outcomes - a single gene that has more than two alleles or outcomes - a trait controlled by 2 alleles - a trait controlled by 2 allelessingle gene How does environment affect genes? Human Inheritance 1. diet – Lack of proteins, minerals, and vitamins can prevent a person from growing to full height. 1. diet – Lack of proteins, minerals, and vitamins can prevent a person from growing to full height. Example: three blood types A, B, & O Example: height at least 4 alleles Example: widow’s peak, white forelock 2. living conditions – Better housing reduces infections and diseases. 2. living conditions – Better housing reduces infections and diseases. How many pairs? 23 pairs of chromosomes in each human body cell Female sex chromosome pair = XX Female sex chromosome pair = XX Male sex chromosomes = XY Male sex chromosomes = XY

Clarifying ?s Information Page 45 Summary: - genes on the X and Y chromosomes - pass from parent to child - traits controlled by sex-linked genes sex-linked genes Sex-linked traits FYI Human Inheritance Only females are sex-linked trait carriers. Males will display the physical trait if they receive it from their mother because the correct matching information for that trait does not occur on the reduced Y chromosome they received from their father. On the other hand, females who receive the sex-linked trait from their mother are more likely to have the correct matching information on the X chromosome they received from their father. This is why color blindness occurs in approximately 8% of males and only about 0.4% of females. Example: color blindness, muscular dystrophy carrier - a person who has one recessive and one dominant allele for a trait They don’t have the physical trait, but they can pass the trait to their offspring. A carrier can carry a regular trait OR a sex-linked trait.

Page 44 Clarifying ?s Information Human Inheritance multiple alleles single gene How does environment affect genes? 1. diet – Lack of proteins, minerals, and vitamins can prevent a person from growing to full height. 1. diet – Lack of proteins, minerals, and vitamins can prevent a person from growing to full height. Example: three blood types A, B, & O Example: height at least 4 alleles Example: widow’s peak, white forelock 2. living conditions – Better housing reduces infections and diseases. 2. living conditions – Better housing reduces infections and diseases. How many pairs? 23 pairs of chromosomes in each human body cell Female sex chromosome pair = XX Female sex chromosome pair = XX Male sex chromosomes = XY Male sex chromosomes = XY

Page 45 Clarifying ?s Information Summary: Human Inheritance - genes on the X and Y chromosomes - pass from parent to child - traits controlled by sex-linked genes sex-linked genes Sex-linked traits FYI Only females are sex-linked trait carriers. Males will display the physical trait if they receive it from their mother because the correct matching information for that trait does not occur on the reduced Y chromosome they received from their father. On the other hand, females who receive the sex-linked trait from their mother are more likely to have the correct matching information on the X chromosome they received from their father. This is why color blindness occurs in approximately 8% of males and only about 0.4% of females. Example: color blindness, muscular dystrophy carrier - a person who has one recessive and one dominant allele for a trait They don’t have the physical trait, but they can pass the trait to their offspring. A carrier can carry a regular trait OR a sex-linked trait.

This PowerPoint was created from Charlene Shea’s lecture notes by Tim Paterek. It is copyrighted and may not be reproduced outside the Vancouver School District. All pictures came from Google Image Search. To fall within the Fair Use Guidelines, this PowerPoint must be used within the confines of the classroom and may not be published back onto the Internet unless the pictures are removed.