Warm- UpIf the pedigree shows the disorder hemophilia caused by a recessive allele (h)…

1.What is the genotype of person 1?

2.What is the genotype of person 2?

3.What is the phenotype of person 4?

Agenda• Objectives: SWBAT: Identify the

probability of a genetic disease occurring in offspring.

• Review Genetics

• Quizzes and Grades

• Group Work

• Brain Pop Video

• Exit Ticket

Brain Pop Video

• http://www.brainpop.com/health/geneticsgrowthanddevelopment/heredity/preview.weml

Review• A couple wants to know how likely

their children will inherit a form of deafness, which is caused by a recessive gene. The mother has no family history of deafness, but the father is heterozygous for the deafness. Use the letter “D” to complete the Punnett Square

People in a town of Alaska have seen some wolves with black coats and blue eyes recently. They want to know how likely it is for a wolf to have both traits. Normal coat color (N) is dominant to black (n) and brown eyes (B) are dominant to blue (b). The alpha male is black with blue eyes and the alpha female is heterozygous for normal colored coat and for brown eyes.

What are their genotypes?

a. How many of the offspring out of 16 living in the pack will have a normal coat and brown eyes?

b. How many of the offspring out of 16 living in the pack will have a black coat and blue eyes?

Sex-linked trait

A boy, whose parents and grandparents had normal vision, is color-blind. What genotype must his mother have in order for him to have color-blindness? Use XB for the dominant normal condition and Xb for the recessive, color-blind phenotype.

Quiz Results and Make-ups

Group ReadingsIn your groups, answer the following questions in your

notebook:

1. What disorder are you reading about?

2. How can a person inherit the disorder? (Is it sex-linked, autosomal, recessive, dominant?)

3. What are some of the symptoms?

4. How prevalent (common) is it?

5. What is the prognosis for a person with the disorder?

6. What is something else we should know about the disorder?

Share Information

Exit TicketA woman is concerned that her children may inherit cystic fibrosis, which runs in her family. She does not have the disorder herself, but she may be a carrier.

1.What would her genotype look like if she is a carrier? (use the letter F)

2.What is the probability that she would have a child with cystic fibrosis?

Warm Up1. Name two diseases that are sex-linked (found on the X-

chromosome)

2. Name two diseases that are autosomal.

3. In the pedigree below, is the trait autosomal or sex-linked?

What are some ways we inherit traits?

Group Readings and Posters• Directions:

– You will be put into small groups– Each group will receive a different reading that everyone

must complete– Once finished, you must answer the questions from your

reading by creating a poster– Make sure to include diagrams and make the poster

colorful– Everyone must participate in making the poster

Exit Ticket

1. Which type of inheritance involves multiple genes?

2. Which type of inheritance leads to a blend of two traits?

Warm Up1.

2. When two traits are equally expressed in an organism, the mode of inheritance is ___________________

Agenda• Objectives: SWBAT: Analyze modes of

inheritance including codominance, incomplete dominance, and multiple alleles, using pedigrees or Punnett squares

• Note taking• Practice Problems• Exit Ticket

How do we inherit traits?

a) The different ways that people inherit traits are called “modes of inheritance”.

b) There are 4 modes of inheritance that you will need to know:

– Complete Dominance– Incomplete Dominance– Codominance– Polygenic Traits

Complete Dominance

• This is when one trait overpowers another.

• The dominant trait is the one that will suppress other traits. (BB or Bb)

• The recessive trait is hidden unless there are two copies of the allele present in the gene. (bb)

What is Incomplete Dominance?

a) Incomplete dominance is when the offspring have a blend of their parents’ traits.

b) Example: If red snapdragons (RR) are crossed with white snapdragons (rr), you get PINK snapdragons (Rr)!

c) The genotypes would be Rr but the flowers will be pink because both traits blended to form a new phenotype.

Example of Incomplete Dominance

Example in Humans

What is Co-dominance?a) Co-dominance is when the two different

alleles are equally expressed in a heterozygous offspring.

b) Both alleles makeup the phenotype without blending together.

c) Example: Not all things in the world are just black or brown! Lots of things are spotted or made of multiple colors due to co-dominant traits.

Co-dominance

What are Polygenic traits?a) Polygenic traits are traits controlled by

two or more genes- “Poly” means many or multiple

b) Polygenic traits often show a wide variety of phenotypes.

c) This type of inheritance is responsible for the wide range of different skin colors in humans. There are more than 4 different genes that determine this trait.

Polygenetic traits

Examples in Humans

• Eye color

• Height

• Weight

• Skin Color

• Blood Type

Multiple Alleles

a) When there are more than two possible alleles for a trait, it’s called multiple allele inheritance

b) In a population, there are multiple alleles that can make up a trait

c) Example: Blood Type - People can have the blood types A, B,

AB or O

Blood Types

Blood Type Practice

Example problem

Andalusian chickens can come in different colors. When a black chicken is crossed with white chicken, they produce a “blue” chicken. The blue Andalusian chicken is called blue because it has both black and white feathers. What type of inheritance is this?

Practice Problems

Exit Ticket1. A cat is spotted. It has white fur and orange

spots. What mode of inheritance is it expressing?

2. A red rose and a yellow rose are crossed and they produce orange offspring. What mode of inheritance is this?

3. Blood types are an example of what mode of inheritance?

Agenda

• Objectives: SWBAT Describe how traits are inherited given scenarios and/or parents’ genetic information AND Define and distinguish between codominance, incomplete dominance, and polygenic traits

• Group Activity• Notes• Practice• Exit Ticket

Mode of Inheritance

Suppose you have two rose plants, both with pink flowers. You cross the two plants and are surprised to find that, while most of the offspring are pink, some are red and some are white. What type of inheritance is this? (incomplete, co-dominance, multiple alleles, polygenic, sex-linked)?