Transcript Human Inheritance - Gaiser Middle School

Human Inheritance
Gaiser Life Science
Know
Human Inheritance
What are some traits a child may
share with one or both parents?
Explain your answer.
Evidence
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.
Page 43
Clarifying ?s
Human Inheritance
Information
multiple
alleles
- a single gene that has more than two alleles or outcomes
single
gene
- a trait controlled by 2 alleles
How does
environment
affect genes?
1. diet – Lack of proteins, minerals, and vitamins can prevent a
person from growing to full height.
2. living conditions – Better housing reduces infections and
diseases.
How many
pairs?
Example: three blood types A, B, & O
Example: height at least 4 alleles
Example: widow’s peak, white forelock
23 pairs of chromosomes in each human body cell
Female sex chromosome pair = XX
Male sex chromosomes = XY
Page 44
Clarifying ?s
Human Inheritance
Information
sex-linked
genes
- genes on the X and Y chromosomes - pass from parent to child
Sex-linked
traits
- traits controlled by sex-linked genes
carrier
FYI
Example: color blindness, muscular dystrophy
- 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.
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.
Summary:
Page 45
Clarifying ?s
multiple
alleles
single
gene
How does
environment
affect genes?
How many
pairs?
Human Inheritance
Information
Example: three blood types A, B, & O
Example: height at least 4 alleles
Example: widow’s peak, white forelock
1. diet – Lack of proteins, minerals, and vitamins can prevent a
person from growing to full height.
2. living conditions – Better housing reduces infections and
diseases.
23 pairs of chromosomes in each human body cell
Female sex chromosome pair = XX
Male sex chromosomes = XY
Page 44
Clarifying ?s
Human Inheritance
Information
sex-linked
genes
- genes on the X and Y chromosomes - pass from parent to child
Sex-linked
traits
- traits controlled by sex-linked genes
carrier
FYI
Example: color blindness, muscular dystrophy
- 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.
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.
Summary:
Page 45
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.