THanks, Mom and Dad

Lesson 6

Anchoring

Two parents are going to have a biological baby. They wanted to know if their child will be able to taste PTC (both parents can taste PTC), and if their child will have any height advantage (The mom is tall and the dad is short). They sent their DNA to be tested so they could see which genes they have.

They got back data about all 46 of their chromosomes.

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Here is the data for just one chromosome pair, which contains the PTC gene and one height gene:

Mom

Dad

Legend

PTC Gene

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PTC Taster

Non-Taster

Gene 1: STQTL17

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Taller

Shorter

Make a prediction: which genes do you think their child will get? Draw the genes you think their child might get.

Explain: how would they get those genes?

Mom

Dad

Legend

PTC Gene

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PTC Taster

Non-Taster

Gene 1: STQTL17

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Taller

Shorter

Uncover Ideas

• On a whiteboard, make a model of what you see happening. Label and explain what you see.
• Model at least 4 steps

• Next we will watch sea urchin reproductive cells combine.
• Add to your model to explain reproduction.

How many of your chromosomes come from each parent?

Complete the handout and we will go over it when we are done.

Let’s Pause and explore Genetic Inheritance/Meiosis

Let’s Practice

On a whiteboard, draw out the table. Determine the number of body cells or sex cell chromosome numbers. Remember, body cells = diploid (2n), sex cells = haploid (n)

Let’s Practice

On a whiteboard, ON HALF of it, draw out the table. Determine the number of body cells or sex cell chromosome numbers.

23

14

38

8

78

18

Keep going...

Now draw this table too. Complete the table using table 1.

Uncover Ideas (2)

Read the article “How do parents pass on their genes?

• What are some examples of traits that can be passed on?
• What are some examples of traits that can’t be passed on?
• Are reproductive cells (sperm and egg cells) always the same?

Share your ideas

• Why do parents only pass on some of their genes?
• With your partner identify similarities and differences you have with your parents. Be ready to share.

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Add these to your vocabulary sheet...

Zygote: A fertilized egg (diploid)

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Add these to your vocabulary sheet...

Recall: Alleles: Slightly different versions of the same gene.

• Ex: The genes for red hair and brown hair

Dominant: A trait that is present when 1 or more copies of the allele are present. (R)

Recessive: A trait that is present only if no copies of the dominant allele are present. (r)

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Genotype: The particular alleles (or genes) an individual carries.

• They (alleles) are inherited from your biological parents.
• Genes control your traits.
• Examples: TT, Aa, mm

Phenotype:An individual’s physical traits.

• What people can see when they look at you.
• Examples: Skin Color, Flower Height, Lizard Tail Length

Heterozygous: An individual with different alleles of a gene.

• Examples: Tt, Aa, Mm

Homozygous: An individual with identical alleles of a gene.

• Examples: TT, tt, AA, aa

• An allele is dominant if its effect masks the effect of a recessive allele paired with it.
• Capital letters (A) signify dominant alleles, lowercase letters (a) signify recessive alleles.

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• Other information...
• Homozygous Dominant = AA
• Homozygous Recessive = aa
• Heterozygous = Aa = always write the dominant allele first

Let’s Practice what we’ve learned

Observable Traits

• You will be completing the observable traits lab activity.
• Feel free to ask others to help you identify some of your traits.
• https://docs.google.com/presentation/d/1OTMIGyMv_mcCFvONGUpGu5cloHOXC7SWbyWBIujVjEo/edit?usp=sharing
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Connect Your Ideas

How did Joe get his Opsin gene?

Legend

Gene 1:

OPN1MW

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Colorblind

Typical Vision

Joe’s Dad

Joe’s Mom

What are the odds?

Check Your Progress

Let’s find out about breeding black labs!

There is a dog breeder that breeds black labs. Both the mother and father dogs have black fur. Usually the puppies are also black, but sometimes the breeder has a puppy with yellow fur. The first time it happened, she was very surprised!

Legend

Gene:

MCR1

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Yellow Color

Black color

Dad Dog

Mom Dog

Puppy

She was so surprised that she had their genes tested! Below are the results.

Legend

Gene:

MC1R

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Yellow Color

Black color

Dad Dog

Mom Dog

Puppy

Help the breeder understand what happened: How did the yellow puppy get his genes?

Now, complete “How did the puppy get his genes?”