KEY
Name ____________________________________________________________ Hour ____
Cells: The Basic Units of Life
Reading Guide
Directions: Read pages 61-75 in the green Life Science textbook and answer the questions as you go.
The Discovery of Cells
1. How were cells discovered by accident?
Robert Hooke built a crude microscope. He was trying to show something interesting to other scientists at
a meeting. When he viewed a slice of cork, he discovered cells.
2. What did Robert Hooke see when he looked at a thin slice of cork with his microscope?
What looked like hundreds of little boxes.
3. Cell means ______little rooms___________ in Latin.
4. Did Hooke think that cells were found in all organisms? Explain.
No. He only looked at plants and fungus so he thought that cells only happened in those organisms.
5. What did Anton van Leeuwenhoek do?
He looked at pond scum and discovered creatures called “animacules”. He noticed the difference in blood
cells between fish, birds, frogs and humans. He was the first to see bacteria.
6. When did scientists realize that all organisms contain cells?
1838-1839
7. List the three parts of the cell theory:
1. All organisms are made of one or more cells.
2. The cell is the basic unit of life in all organisms.
3. Cells come from existing cells.
Choose the cell feature in Column B that best matches the phrase in Column A, and write the letter in the
space.
Column A
Column B
8. __B__ barrier between the inside of a cell
a. cytoplasm
and its environment.
b. cell membrane
9. __D__ structures that a cell uses to live,
c. DNA
grow, and reproduce
d. organelles
10. __A__ the fluid in a cell and almost
everything in the fluid.
11. __C__ controls all activities of a cell and
contains the information needed for a cell to
make new cells.
12. Could an amoeba become large enough to eat New York City? Why or why not?
No. The larger the cell gets, the more food it needs and the more wast e it produces.
13. In addition to being able to grow larger, what is another benefit of being multicellular?
It allows specialization for specific jobs, which then allows for more functions than unicellular organisms.
14. Name two differences between prokaryotic and eukaryotic cells.
Prokaryotic – Circular DNA, No nucleus, No membrane covered organelles. (Bacteria)
Eukaryotic – Linear DNA, Have a nucleus, Have membrane covered organelles. (Protists, Fungi, Plants,
Animals)
Eukaryotic Cells: The Inside Story
15. What two things helped scientists see more details in cells?
Improved magnification and improved staining.
16. What is the function of the cell membrane?
Keep the cytoplasm in allow nutrients in and waste out.
17. In a eukaryotic cell, the largest organelle is the __________Nucleus_______________________.
18. The _____Nucleolus_______________________ is the dark spot inside the nucleus that stores
materials used to make ribosomes.
19. Would cells die if they didn’t have ribosomes? Explain.
All cells need protein to live and ribosomes create protein from amino acids.
20. What does the endoplasmic reticulum (ER) do?
It makes lipids for use inside and outside the cell, breaks down drugs and other substances and provides
transport for materials through the cell.
21. ________Ribosomes_________________ cause the surface of some ER to look rough.
22. What do mitochondria do?
They create energy in the form of ATP for the cell. They are the cell’s powerhouse.
23. What do chloroplasts do?
Turn sunlight into energy for plants.
24. According to one theory, mitochondria and chloroplasts originated s bacteria. True or False?
25. The Golgi complex processes, packages, and transports materials sent to it from the
__Endoplasmic Reticulum__________.
26. What do lysosomes do?
Destroy worn out or damaged organelles and get rid of waste materials to protect the cell.
27. Why don’t humans have webbed fingers?
Because lysosomes destroy the damaged cells.
28. If you look at a cell through a microscope, how can you tell whether it is a plant or animal cell?
Yes. Plant cells have a cell wall, chloroplasts and large vacuoles. Animal cells don’t.