11.17_6thSci_TR 3.1

TR 3.1 - "Why Are Identical Twins so Rare"

Objective:  KWBAT obtain and evaluate information about inheritance in humans and what can cause offspring to have different gene combinations even though they have the same parents.

Part 1: Do Now

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The picture above shows three brothers. They share the same genes but they have different traits.

Predict: how is it possible that they have different traits even if they have the same parents?

Part 2: Introducing the Chapter 3 Question
Welcome back!  As a reminder, we are trying to help Bay Medical Company determine how to breed spiders that will produce offspring with the trait for medium silk flexibility to use for medical purposes. We need to determine why Darwin’s bark spiders’ offspring have different traits for silk flexibility.
Here is the updated model that you worked on in the last lesson; as you can see, we now know the correct gene versions for each of the offspring:

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Predict:
Why do the Darwin’s bark spider offspring have different gene combinations even though they have the same parents?

Claim 1: The offspring have mutations that affect their traits.

Claim 2: The offsprings' traits depend on which parent the offspring received more copies of genes from.

Claim 3: The offspring received different combinations of gene versions from their parents.

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Explain your answer choice for question #2.

Sentence Starter:
I think claim _ answers the Chapter 3 question because...

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Review: A spider was found to have the F1F2 gene version. Based on what you know about gene versions and their numbers answer the following question:

Which of the following is true about the F1 and F2 gene versions?

They each cause the silk flexibility to increase

One is found in males, the other in females

They cannot be found in the same spider

They have instructions for different proteins

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Review: From the image above, which of the following gene versions are homozygous?

Offspring A: F1 & F1

Offspring B: F1 & F2

Offspring C: F1 & F1

Offspring D: F2 & F3

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Review: From the image above, which of the following gene versions are heterozygous?

Offspring A: F1 & F1

Offspring B: F1 & F2

Offspring C: F1 & F1

Offspring D: F2 & F3

Part 3: Reading "Why are Identical Twins so Rare?"

To help us understand why offspring from the same parents can have different genes, let’s look at the opposite situation: what about offspring that do have identical genes?

https://ereader.learning.amplify.com/#/reader/e92eaf9a-b240-4030-82c6-408ff4d2287d

Link to article on Amplify.

1

Find a quote that answers this question:

Why do people have different traits?

1

We inherit our genes from our biological parents through the process of __________

1

Draggable item		Corresponding Item

1

Find a quote that answers this question:

What is fertilization?

1

How many times does fertilization happen in fraternal twins?

1 time

3 times

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1

How many times does fertilization happen in identical twins?

1 time

3 times

2 times

Part 4: Exit Ticket

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Most cells have copies of each gene, but reproductive cells like sperm or eggs have .

1, 2

2, 1

2, 2

10, 5

1

Reflect:

Angel looks very similar to his other 2 siblings. They all have the same parents.

Why do they look similar, but not identical?

Identical means EXACTLY the same.

MS-LS3-2

Try these:
Dragon Genetics game - https://geniventure.concord.org/#/home
READ
Prodigy

Draggable item		Corresponding Item
From mother		sperm cells
From father		egg cells

11.17_6thSci_TR 3.1

Part 1: Do Now

The picture above shows three brothers. They share the same genes but they have different traits.Predict: how is it possible that they have different traits even if they have the same parents?

Part 2: Introducing the Chapter 3 Question

Predict: Why do the Darwin’s bark spider offspring have different gene combinations even though they have the same parents?

Explain your answer choice for question #2.Sentence Starter:I think claim _ answers the Chapter 3 question because...

Review: A spider was found to have the F1F2 gene version. Based on what you know about gene versions and their numbers answer the following question:Which of the following is true about the F1 and F2 gene versions?

Review: From the image above, which of the following gene versions are homozygous?

Review: From the image above, which of the following gene versions are heterozygous?

Part 3: Reading "Why are Identical Twins so Rare?"

Find a quote that answers this question:Why do people have different traits?

Find a quote that answers this question:What is fertilization?

How many times does fertilization happen in fraternal twins?

How many times does fertilization happen in identical twins?

Part 4: Exit Ticket

Most cells have ____ copies of each gene, but reproductive cells like sperm or eggs have ____.

Reflect:Angel looks very similar to his other 2 siblings. They all have the same parents.Why do they look similar, but not identical?Identical means EXACTLY the same.

Part 1: Do Now

The picture above shows three brothers. They share the same genes but they have different traits.Predict: how is it possible that they have different traits even if they have the same parents?

Part 2: Introducing the Chapter 3 Question

Predict: Why do the Darwin’s bark spider offspring have different gene combinations even though they have the same parents?

Explain your answer choice for question #2.Sentence Starter:I think claim _ answers the Chapter 3 question because...

Review: A spider was found to have the F1F2 gene version. Based on what you know about gene versions and their numbers answer the following question:Which of the following is true about the F1 and F2 gene versions?

Review: From the image above, which of the following gene versions are homozygous?

Review: From the image above, which of the following gene versions are heterozygous?

Part 3: Reading "Why are Identical Twins so Rare?"

Find a quote that answers this question:Why do people have different traits?

Why do identical twins look alike?

Match the type of reproductive cells that are from the mother and from the father.

True or False:While most cells have two copies of every gene, sperm cells and egg cells only have one copy of each gene.

Find a quote that answers this question:What is fertilization?

True or false:Fertilization happens when sperm and egg cells come together.

How does genetic variation happen?

How many times does fertilization happen in fraternal twins?

Identify:What is the difference between fraternal twins and identical twins?

How many times does fertilization happen in identical twins?

Part 4: Exit Ticket

Most cells have ____ copies of each gene, but reproductive cells like sperm or eggs have ____.

Reflect:Angel looks very similar to his other 2 siblings. They all have the same parents.Why do they look similar, but not identical?Identical means EXACTLY the same.

Why do identical twins look alike?

True or False:While most cells have two copies of every gene, sperm cells and egg cells only have one copy of each gene.

True or false:Fertilization happens when sperm and egg cells come together.

How does genetic variation happen?

Identify:What is the difference between fraternal twins and identical twins?

The picture above shows three brothers. They share the same genes but they have different traits.

Predict: how is it possible that they have different traits even if they have the same parents?

Predict:
Why do the Darwin’s bark spider offspring have different gene combinations even though they have the same parents?

Explain your answer choice for question #2.

Sentence Starter:
I think claim _ answers the Chapter 3 question because...

Review: A spider was found to have the F1F2 gene version. Based on what you know about gene versions and their numbers answer the following question:

Which of the following is true about the F1 and F2 gene versions?

Find a quote that answers this question:

Why do people have different traits?

Find a quote that answers this question:

What is fertilization?

Most cells have copies of each gene, but reproductive cells like sperm or eggs have .

Reflect:

Angel looks very similar to his other 2 siblings. They all have the same parents.

Why do they look similar, but not identical?

Identical means EXACTLY the same.

The picture above shows three brothers. They share the same genes but they have different traits.

Predict: how is it possible that they have different traits even if they have the same parents?

Predict:
Why do the Darwin’s bark spider offspring have different gene combinations even though they have the same parents?

Explain your answer choice for question #2.

Sentence Starter:
I think claim _ answers the Chapter 3 question because...

Review: A spider was found to have the F1F2 gene version. Based on what you know about gene versions and their numbers answer the following question:

Which of the following is true about the F1 and F2 gene versions?

Find a quote that answers this question:

Why do people have different traits?

True or False:

While most cells have two copies of every gene, sperm cells and egg cells only have one copy of each gene.

Find a quote that answers this question:

What is fertilization?

True or false:

Fertilization happens when sperm and egg cells come together.

Identify:

What is the difference between fraternal twins and identical twins?

Most cells have copies of each gene, but reproductive cells like sperm or eggs have .

Reflect:

Angel looks very similar to his other 2 siblings. They all have the same parents.

Why do they look similar, but not identical?

Identical means EXACTLY the same.

True or False:

While most cells have two copies of every gene, sperm cells and egg cells only have one copy of each gene.

True or false:

Fertilization happens when sperm and egg cells come together.

Identify:

What is the difference between fraternal twins and identical twins?