Unit 3 Lesson 1 What Are Cells? - · PDF fileUnit 3 Lesson 1 What Are Cells? The cell theory:...

Unit 3 Lesson 1 What Are Cells?

Copyright © Houghton Mifflin Harcourt Publishing Company


Let’s think!!!


Let’s watch thevideo


Classwork 1:Question 1:


N.B: an amoeba is a very small living organism that is alittle bit bigger than bacteria.


What builds up our bodies?• Cells are the basic units of structure and function

in a living thing. ( Organism)


• Cells are the basic units of structure and functionin a living thing. ( Organism)



Nerve cells – skin cells - blood cells

Copyright © Houghton Mifflin Harcourt Publishing CompanyText book p. 104


Robert Hooke



The cell theory:Scientists developed the cell theory that states:

• 1- All living things are made of cells.

• 2- All life processes take place in cells.

• 3- New cells come from existing cells.


Scientists developed the cell theory that states:

• 1- All living things are made of cells.

• 2- All life processes take place in cells.

• 3- New cells come from existing cells.


Think of it…

• What are the differences betweenanimal and plant cells?

*Observe the plant and the animalcells to spot out what’s common andwhat’s different.


• What are the differences betweenanimal and plant cells?

*Observe the plant and the animalcells to spot out what’s common andwhat’s different.


Think of it…


• 1-Nucleus:

It controls all the cellactivities like:

- Making new cells

- Energy production

- Getting rid of wastes


What Parts Do Cells Have?(Animal and Plant cells)

• 1-Nucleus:

It controls all the cellactivities like:

- Making new cells

- Energy production

- Getting rid of wastes


• 2- Cell membranes:

-It controls what enters andleaves the cell.


• 2- Cell membranes:

-It controls what enters andleaves the cell.


• 3- Mitochondria:

- Releases energy that the cells use to do their jobs.


• 3- Mitochondria:

- Releases energy that the cells use to do their jobs.


• 4-Cytoplasm:

- The jellylike cytoplasm gives the cell shape and holdsthe cell parts together.



• 1- The cell wall:

- Protects plant cells and helps the plant keep itsshape.


What Other Parts Do plant Cells Have?


• 1- The cell wall:

- Protects plant cells and helps the plant keep itsshape.

• The chloroplast uses the sun’s energy to makesugar to feed the plant.

• It gives the plant it’s green color.


• 2- The Chloroplast:


• The vacuole in a plant cell stores water, nutrients,and waste.

• In animal cells, the vacuole is much smaller.


3- The vacuole:




-Uses sunlight to make food.- controls what enters or leaves cell- controls all cell activity



-Try to act the function of each cellpart without talking in 10 seconds.

-If you know the cell part try to stickit on the board on the animal andplant cell diagram.


-Try to act the function of each cellpart without talking in 10 seconds.

-If you know the cell part try to stickit on the board on the animal andplant cell diagram.


Activity time:



Fun time :

Let’s listen to the song


Fun time :

Let’s listen to the song


Can cells divide?

Cell division makes two cells from one.

Why?Copyright © Houghton Mifflin Harcourt Publishing Company

Can cells divide?

Cell division makes two cells from one.

Why?


Why do cells divide?Cells divide for two reasons:

1- To grow.

2-To reproduce.


Why do cells divide?Cells divide for two reasons:

1- To grow.

2-To reproduce.


What is inside the Nucleus? :• Chromosomes are structuresin the cell’s nucleusmade of DNA.

• DNA is made ofsections called genes.

• Genes control an organism’s characteristicssuch as:

(Height , eye color, skin color, ability to rollyour tongue)


• Chromosomes are structuresin the cell’s nucleusmade of DNA.

• DNA is made ofsections called genes.

• Genes control an organism’s characteristicssuch as:

(Height , eye color, skin color, ability to rollyour tongue)


Classwork 2:Question 2:Complete using words from the box:

Gene – DNA –chromosome - nucleus



Where Do Traits Come From?• Inherited traits are characteristics passed

from parents to their offspring.

• Examples of these characteristics might includeeye color, hair color, freckles, and face shape inhumans, and fur color and texture in animals.


• Inherited traits are characteristics passedfrom parents to their offspring.

• Examples of these characteristics might includeeye color, hair color, freckles, and face shape inhumans, and fur color and texture in animals.


Why are there genetic differences• Genetic differences are because an organism

receives only half of its genes from eachparent.

• This results in genetic differences betweenparents and offspring.


• Genetic differences are because an organismreceives only half of its genes from eachparent.

• This results in genetic differences betweenparents and offspring.


Dominant and Recessive Traits :

• Mendel hypothesized that traits in organismsare controlled by a pair of factors and eachparent passes on one factor.


• Mendel hypothesized that traits in organismsare controlled by a pair of factors and eachparent passes on one factor.


• Strong traits that will appear are called :Dominant traits. (eg. Tallness)

• Weak traits that will not appear are called :recessive traits. (eg. Shortness)

• A recessive trait appears only if the 2 factorsare recessive.

• What happens if a child is having a tallnessfactor (dominant) and a shortness factor

( recessive)?• What happens if a child is having 2 shortness

factors (recessive)?


• Strong traits that will appear are called :Dominant traits. (eg. Tallness)

• Weak traits that will not appear are called :recessive traits. (eg. Shortness)

• A recessive trait appears only if the 2 factorsare recessive.

• What happens if a child is having a tallnessfactor (dominant) and a shortness factor

( recessive)?• What happens if a child is having 2 shortness

factors (recessive)?

Unit 3 Lesson 1 What Are Cells? - · PDF fileUnit 3 Lesson 1 What Are Cells? The cell theory:...

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