Download Name: Period: Lesson 2: Nucleus Lesson 2: What Does the Nucleus

Name:____________________________________
Period: ____________________
Lesson 2: Nucleus
Lesson 2: What Does the Nucleus Do?
Directions:
1. Watch and listen to the introduction of this activity. Your teacher will play this for you.
2. Here are two models of what a nucleus does. You will use 3 pieces of evidence to determine
which model is better. Read each of the two models.
CONTROL CENTER MODEL
The nucleus is the control center of the cell. It is like a brain. It works like this:
The nucleus is a membrane with
strands of DNA inside. Each
strand of DNA is a sequence of
genes. A gene is a small bit of
DNA.

The DNA and its genes in
the nucleus give orders to
the other parts of the cell
and tell them what to do.

The other parts of
the cell follow the
orders.
INSTRUCTIONS MODEL
The nucleus gives instructions to make cell structures. It works like this:
The nucleus is a
membrane with
strands of DNA inside.
Each strand of DNA is a
sequence of genes. A
gene is a small bit of
DNA.

Each gene gives instructions to
the cell to make particular
chemical structures.
Different genes give instructions
to make different chemical
structures.

The chemical structures
do things in the cell.
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3. The next three pieces of evidence are presented on the computer. In groups, start reading
evidence #1. When finished, start reading Evidence #2, and then move on to Evidence #3.
Evidence #1
5. Read the Diabetes study in groups on the computer. Follow the directions you see on the
computer.
6. In groups, discuss this question and write your best answer: What do you conclude from the
results of this study?
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7. Individually, add evidence ratings and arrows for Evidence #1 on Page 3. Then in pairs, discuss
your ratings and arrows using the evidence and arrow stems.
Remember for evidence rating:
0 = Very bad
1 = Pretty bad
2 = Pretty good
3 = Excellent
Evidence #2
8. Read the Scientific American Blog in your groups on the computer. Follow the directions that
you see in the blog.
9. Individually, answer this question: How good or bad is Evidence #2? Write your reasons for
your answer.
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10. Individually, add evidence ratings and arrows for Evidence #2 on Page 3 below. Then in pairs,
discuss your ratings and arrows using the evidence and arrow stems.
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Evidence #3
11. Read the information from the website www.ineedhelp.com in your groups on the computer.
12. Individually, add evidence ratings and arrows for Evidence #3 on Page 3 below. Then in pairs
discuss your ratings and arrows using the evidence and arrow stems.
Arrows Diagram:
Evidence Goodness
Control Center Model
Instructions Model
#1. Diabetes. When there is a
mutation in the DRB gene,
patients cannot produce insulin.
#2. Glow in the dark cat
evidence. The gene for a glowing
protein was put
into cats and the
cats produced the
protein, so they
glowed.
#3. I NEED HELP. The nucleus is
like the brain of the cell.
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Remember when writing:
Evidence can contradict, support, strongly contradict, strongly support or have nothing to do
with a model
13. Individually, answer this question: How is Evidence #1 related to the Control Center model
(supports, contradicts, etc.)? Give reason for your answer.
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14. Individually, answer this question: How is Evidence #1 related to the Instructions model
(supports, contradicts, etc.)? Give reasons for your answer.
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Model Evaluation
15A. Discuss in your groups: Which model is better, based on the evidence so far. Give detailed
reasons for your ideas during your discussion (use model evaluation stems).
15B. Then answer the following questions.
Which evidence is the best evidence?
Which evidence supports or contradicts both models MOST STRONGLY?
Which evidence helps you the most to decide which model is better?
What is the best argument for the control center model?
What is the best argument for the instructions model?
What is the worst argument for either model?
What other evidence would you like to have?
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16. Individually, answer this question: What is the best model of the function of the nucleus?
Give 2 reasons and 2 explanations using details from the evidence of your reasons.
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The Function of the Nucleus
17. Individually, answer these questions:
a. What is the function of the nucleus?
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b. What would happen if you took the nucleus of a mouse egg and put it in a chicken egg?
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