1. Unit 3 Lesson 1 What Are Cells?
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2. Vocabulary cell organism cell membrane nucleus inherited trait
Unit 3 Lesson 1 What Are Cells?
Vocabulary
cell
organism
cell membrane
nucleus
inherited trait
dominant trait
recessive trait
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3. Unit 3 Lesson 1 What Are Cells?
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4. Unit 3 Lesson 1 What Are Cells?
All Made of Cells
Cells are the basic units of structure and function in a living thing. The bodies of all living things are made up of cells, including nerve and skin cells.
Living things are also called organisms and can be made up of one cell or trillions of cells.
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5. Unit 3 Lesson 1 What Are Cells?
All Made of Cells
People did not know cells existed because cells were microscopic, or not visible without a microscope.
Robert Hooke was the first person to study cells using a microscope.
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6. All Made of Cells Scientists developed the cell theory that states:
Unit 3 Lesson 1 What Are Cells?
All Made of Cells
Scientists developed the cell theory that states:
All living things are made of cells.
All life processes take place in cells.
New cells come from existing cells.
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7. All Made of Cells Text book p. 104 Unit 3 Lesson 1 What Are Cells?
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8. All Made of Cells Exit Slip
Unit 3 Lesson 1 What Are Cells?
All Made of Cells Exit Slip
Brain check p.118
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9. All Made of Cells H.W Text book p.103 Unit 3 Lesson 1 What Are Cells?
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10. What Parts Do Cells Have?
Unit 3 Lesson 1 What Are Cells?
What Parts Do Cells Have?
Plants and animals are made of cells, but they need different cell parts to stay alive.
The nucleus
Makes more cells.
produces energy.
Takes in materials.
Gets rid of wastes.
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11. What Parts Do Cells Have?
Unit 3 Lesson 1 What Are Cells?
What Parts Do Cells Have?
Cell membranes control what enters and leaves the cell.
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12. What Parts Do Cells Have?
Unit 3 Lesson 1 What Are Cells?
What Parts Do Cells Have?
Mitochondria release energy that the cells use to do their jobs.
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13. What Parts Do Cells Have?
Unit 3 Lesson 1 What Are Cells?
What Parts Do Cells Have?
The jellylike cytoplasm gives the cell shape and holds the cell parts together.
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14. What Parts Do Cells Have?
Unit 3 Lesson 1 What Are Cells?
What Parts Do Cells Have?
The cell wall protects plant cells and helps the plant keep its shape.
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15. What Parts Do Cells Have?
Unit 3 Lesson 1 What Are Cells?
What Parts Do Cells Have?
The chloroplast uses the sun’s energy to make sugar to feed the plant.
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16. What Parts Do Cells Have?
Unit 3 Lesson 1 What Are Cells?
What Parts Do Cells Have?
The vacuole in a plant cell stores water, nutrients, and waste. In animal cells, the vacuole is much smaller.
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17. What Parts Do Cells Have? Exit Slip
Unit 3 Lesson 1 What Are Cells?
What Parts Do Cells Have? Exit Slip
Text book p.107
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18. What Parts Do Cells Have? H.W.
Unit 3 Lesson 1 What Are Cells?
What Parts Do Cells Have? H.W.
Brain check p.118
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19. What Parts Do Cells Have? H.W.
Unit 3 Lesson 1 What Are Cells?
What Parts Do Cells Have? H.W.
Brain check p.119
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20. Cells Divide and Multiply
Unit 3 Lesson 1 What Are Cells?
Cells Divide and Multiply
Cell division makes two cells from one.
Cells divide for two reasons:
to grow
As cell division occurs, the organism grows.
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21. Cells Divide and Multiply
Unit 3 Lesson 1 What Are Cells?
Cells Divide and Multiply
to reproduce.
When organisms reproduce, they make egg and sperm cells through cell division.
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22. Cells Divide and Multiply
Unit 3 Lesson 1 What Are Cells?
Cells Divide and Multiply
Chromosomes are structures in the cell’s nucleus made of DNA. DNA is made of sections called genes.
Genes control an organism’s characteristics.
An organism’s characteristics, such as height or eye color, come from the parent’s cells when they reproduce.
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23. Unit 3 Lesson 1 What Are Cells?
How Cells Divide
Mitosis is a six-step process that allows the organism to grow.
Each chromosome is copied.
Chromosome are joined.
Chromosomes line up in the middle.
Chromosomes separate and move to opposite ends of the cell.
A nuclear membrane is formed.
Finally, the cytoplasm divides
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24. Mitosis Animation

25. Unit 3 Lesson 1 What Are Cells?
How Cells Divide
Meiosis forms eggs and sperm, or sex cells, which have half as many chromosomes as body cells.
Egg and sperm cells join to form a new single cell during sexual reproduction.
The single cell divides by mitosis and grows into a new individual.
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26. How Cells Divide Text book p.111 Unit 3 Lesson 1 What Are Cells?
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27. How Cells Divide Exit Slip
Unit 3 Lesson 1 What Are Cells?
How Cells Divide Exit Slip
Brain check p.118
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28. How Cells Divide Exit Slip
Unit 3 Lesson 1 What Are Cells?
How Cells Divide Exit Slip
Brain check p.120
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29. How Cells Divide H.W. Brain check p.120
Unit 3 Lesson 1 What Are Cells?
How Cells Divide H.W.
Brain check p.120
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30. Where Do Traits Come From?
Unit 3 Lesson 1 What Are Cells?
Where Do Traits Come From?
Meiosis causes genetic differences since an organism receives only half of its genes from each parent.
This results in genetic differences between parents and offspring.
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31. Where Do Traits Come From?
Unit 3 Lesson 1 What Are Cells?
Where Do Traits Come From?
Inherited traits are characteristics passed from parents to their offspring.
Examples of these characteristics might include eye color, hair color, freckles, and face shape in humans, and fur color and texture in animals.
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32. Where Do Traits Come From?
Unit 3 Lesson 1 What Are Cells?
Where Do Traits Come From?
Text book p. 113
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33. Dominant and Recessive Traits
Unit 3 Lesson 1 What Are Cells?
Dominant and Recessive Traits
In the 1800s, Gregor Mendel observed height differences in pea plants.
Mendel investigated how the height trait was passed on from parent plants.
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34. Dominant and Recessive Traits
Unit 3 Lesson 1 What Are Cells?
Dominant and Recessive Traits
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35. Dominant and Recessive Traits
Unit 3 Lesson 1 What Are Cells?
Dominant and Recessive Traits
Mendel hypothesized that traits in organisms are controlled by a pair of factors and each parent passes on one factor.
In the pea plants, tallness was a strong, or dominant trait. Shortness was a weak, or recessive trait.
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36. Dominant and Recessive Traits
Unit 3 Lesson 1 What Are Cells?
Dominant and Recessive Traits
Text book p. 115
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37. Where Do Traits Come From? Exit Slip
Unit 3 Lesson 1 What Are Cells?
Where Do Traits Come From? Exit Slip
Brain check p. 119
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38. Unit 3 Lesson 1 What Are Cells?
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