Inheritance of Alleles

Inheritance of Alleles

​***Be sure to read each slide before moving on

Scores under 70 will require you to repeat the lesson​

By Christina Peralta

​Find the chromosomes you will model with

Subject | Subject

Some text here about the topic of discussion

Discuss with your partner, what do you think the two different colors represent?

For this activity-

maternal (mom) chromosomes will be white paternal (dad) chromosomes will be blue

Multiple Choice

What do you think the two different colors represent?

• The paper Mrs. Peralta had available

• A set of chromosomes from mom and a set from dad

• Chromosomes after replication

Key Vocabulary

Cells that have pairs of chromosomes (like the one you are using for this simulation) are called diploid (di=2). Chromosomes inherited by the parents are called homologous, because they contain the information for the same traits (homo- = same). The section on the DNA that codes for a specific trait is called a gene.

Subject | Subject

Some text here about the topic of discussion

Fill in the Blanks

How many genes are found on chromosome 3?

Fill in the Blanks

How many genes are on chromosome 12?

​Genes and Alleles

For each gene there may be different actual sequence of bases, these different sequences (versions of a gene) are called alleles. Capital and lowercase letters are used to represent different sequences (dominant versions and recessive versions).

Let’s pretend the chromosomes you have at your table are Fred's chromosomes.

​

Subject | Subject

Some text here about the topic of discussion

Fill in the Blanks

How many alleles are present for each gene? Use evidence from the chromosomes to suport your answer (but just put in a # for this quesiton)

Homologous Chromosomes

Homologous chromosomes are the same chromosome number. One comes from mom (maternal chromosome) and one comes from dad (paternal chromosome).

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Make homologous pairs of chromosome 3 and chromosome 12 at your desk.

Subject | Subject

Some text here about the topic of discussion

STOP!

Ask Mrs. Peralta to come and check your work

​- Mrs. Peralta

(Do you have a chromosome 3 paired in different colors and chromosome 12 paired in different colors?...then you are correct!) **just don't attach them like they are sister chromatids- they are not exact copies of each other.

Fill in the Blanks

On which chromosome can we find: “Gene F” (let’s pretend it codes for freckles)?

Type the chromosome number only

Fill in the Blanks

On which chromosome can we find: “Gene M” (let’s pretend it codes for Melanin/darker skin color)?

Fill in the Blanks

On which chromosome can we find: “Gene R” (let’s pretend it codes for rolling your tongue)?

Genotype: the allelic combination of an organism (ex: the letters for each gene in each chromosome in the cell).

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If every gene will always have 2 alleles (one that came from mom and one that came from dad), identify the genotype of the following genes: 

Subject | Subject

Some text here about the topic of discussion

Fill in the Blanks

What is the genotype for “Gene A” (let’s pretend it codes for A blood group)? Give the dominant letter first. Upper/lowercase matters!

Multiple Choice

This genotype is-

• homozygous dominant

• homozygous recessive

• heterozygous

Fill in the Blanks

What is the genotype for “Gene D” (let’s pretend it codes for dimples)?

Multiple Choice

This genotype is-

• Homozygous dominant

• Heterozygous

• Homozygous recessive

• Heterozygous dominant

Fill in the Blanks

What is the genotype for “Gene P” (let’s pretend it codes for PTC tasting)?

Multiple Choice

This genotype is-

• Homozygous recessive

• Heterozygous

• Homozygous dominant

At the end of meiosis, the total number of chromosomes will be reduced in half. While the parent cell will start with a set of chromosomes from each parent, the resulting gametes may have a mix of each parent’s chromosomes. The gametes may contain more chromosomes from mom than dad. This is why your siblings will never be exactly the same as you. 

Choose the following chromosomes: maternal chromosome #3, paternal chromosome #12. These are going to represent a possible set of chromosomes found in a gamete after meiosis.

Subject | Subject

Some text here about the topic of discussion

STOP!

Ask Mrs. Peralta to come and check your work

Multiple Choice

Could this gamete pass on 

a dominant allele for ‘A’ blood group?

• Yes

• No

• Possibly

Multiple Choice

Could this gamete pass on a dominant allele for Freckles?

• Yes

• No

• Possibly

Multiple Choice

Could this gamete pass on a recessive allele for Dimples?

• Yes

• No

• Possibly

Multiple Choice

Could this gamete pass on a recessive allele for Melanin?

• Yes

• No

• Possibly