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Unit 2: Study Guide - Cells
Name:____________KEY__________________
Answer the following questions. Unit 2 vocabulary will also be checked on Test Day!
1. The discovery of the cell was possible due to the invention of the ____Microscope______________________.
2. List the 3 parts of the cell theory.
a. All organisms are composed of one or more cells.
b. The cell is the basic unit of structure and functions of organisms.
c. All cells come from preexisting cells
3. How do you find the total magnification of a microscope?
Eyepiece x objective = total magnification
4. Describe the function of the following microscope parts…
a. Eyepiece- the piece you look through
b. Objective- the structures used to magnify the image. They come in 4x, 10x, and 40x power/sizes.
c. Stage- The area where you place the slide
d. Course adjustment- The larger knob that you use to focus the image at the lowest power (4x).
e. Fine adjustment- The smaller knob used to focus the image at the higher powers (10x and 40x).
f. Diaphragm- The structure that controls the amount of light hitting the slide.
5. Distinguish between prokaryotes and eukaryotes. Give an example of each.
Prokaryotes: are simple, old (in terms of evolution), do not have a nucleus but do have DNA in their cytoplasm.
The only types of prokaryotic cells are bacteria.
Eukaryotes: are very complex, recent (in terms of evolution), have a nucleus and many organelles. All the types
of plant and animal cells are eukaryotes.
6. Fill in the following chart!
Organelle
Function
Found in (prok,
plant, or animal)?
Plasma
Membrane
Ribosomes
Controls what enters and leaves the cell
Both/ all cells!
Make proteins
Both/all cells
Cytoplasm
The fluid in the cell that surrounds the organelles.
Both/ all cells
DNA
Deoxyribonucleic acid. The genetic material in the cell the code
for proteins and traits. Also controls all cell processes.
Both/ all cells
Nucleus
Controls all cell functions because it contains the cells DNA.
“command center”
Both plant and animal
Cell Wall
Provides structure, support , and protection. Located around the
plasma membrane
Plant cell only
Plasmid
Do not need to know for this unit, but this is what we call the DNA
found in prokaryotes. We will learn this in a later unit
Prokaryotes only
Mitochondrion
Provides energy for the cell in the form of ATP. The “powerhouse”
aka mighty mitochondria!
Both plant and animal
Chloroplast
Converts solar energy to sugar. Makes food for the plant. It’s the
site of photosynthesis
Plant only
Golgi Body
(apparatus)
Packages proteins. “Cell UPS”
Both plant and animal
Vacuole
Stores water and waste
Plant cell only
Endoplasmic
Reticulum
Transports proteins to other parts in the cell
Plant and animal
Lysosomes
Break apart and digest proteins that will be reused or removed
from the cell
Animal only
Nucleolus
The small region (circle) inside the nucleus where all the DNA is
found. Do not need to know how to label this.
Animal and plant
Centrioles
Organelles that help the cell divide to make more cells.
Animal cell only
7. Distinguish between plant and animal cells. Draw and label one of each
Plant cells have a chloroplast, vacuole,and cell wall, but do not have centrioles and lysosomes. They are always drawn
square shape
Animal Cells have centrioles and lysosomes, but do not have chloroplast, cell wall, or vacuole. They are always circle
shaped. We learned about many types of animal cells such as sperm, red blood cell, egg cell, skin,etc. These are all
types of animal cells that look a specific way to fit their function.
See the pictures we labeled in class. These are the most similar to the pictures on test. Can also find many examples on
google image.
8.
Describe the function of the plasma membrane. Label the following diagram with: phospholipid, polar head,
nonpolar tail, transport protein. The plasma membrane controls what enters and leaves the cell. The structure
of the plasma membrane plays a critical role in its ability to do this. The membrane is made up of a phospholipid
bilayer. The chemical properties of a phospholipid allow the membrane to be semi-permeable, allowing some
molecules to pass through while blocking others, and the membrane also has protein channels to let bigger
molecules inside or outside the cell
Phospholipid head
Phospholipid tails
Protein channel
9. The cell membrane is said to be selectively permeable. What does this mean? The membrane is selective about
what can enter the cell. The chemical properties of the cell membrane determine this selection. Because gas
molecules are so small, they can easily pass in and out of the cell. Other molecules can get in and out via protein
channels, while some will never be able to enter and/or leave the cell.
10. Define cell differentiation. Why is it important for cells to specialize? Explain how cells differentiate.
Cell differentiation is the process in which a cell (usually a stem cell) is able to develop into any type of specialized cell.
Cells need to specialize in order to perform certain functions. The instructions in DNA tell a stem cell which cell to
differentiate in to.
11. Identify the following cells…
Red blood cell
muscle cells
neuron
sperm cell
12. How are stem cells different from other cells? Distinguish between embryonic stem cells and adult stem cells.
Stem cells have the ability to differentiate into a specialized cell because they are undifferentiated cells. Embryonic stem
cells are the most powerful because they are found in early developing embryos and have the ability to differentiate into
any type of cell. Adult stem cells are more rare in the body. They are mostly only found in the bone marrow, and these
can only become red and white blood cells. However, scientists are finding adult stem cells in other tissues such as
muscle and skin. The adult stem cell can only differentiate into a certain type of cell, based on where it is found in the
body.
13. List the levels of organization in a multicellular organism.
Organic compounds  organelles  cells  tissue  organ  organ system organism
14. Describe 2 of the ways that cells communicate.
Cells can communicate by sending molecules (chemicals) directly through the cell membrane. Cells can also send
electrical impulses to communicate. Cells that are far away from each other can communicate via hormones binding to
receptors on the cell membrane.
15. List and describe the three types of passive transport.
Osmosis: water moving across the membrane from areas of high concentration to low concentration.
Diffusion: molecules moving across the membrane from areas of high concentration to low concentration.
Facilitated diffusion: molecules moving across the cell membrane through a protein channel from areas of high
concentration to low concentration. All of these types of transport do not require energy!!
16. Show the direction of water movement in each of the following systems. Tell whether the solution is
hypertonic, isotonic, or hypotonic.
1st beaker: Isotonic solution. Water is not moving across the membrane. Even amount on both sides of cell.
2nd beaker: Hypotonic solution. Water will rush into the cell, because there is more water in solution than in the cell. Cell
swells.
3rd beaker: Hypertonic solution. Water rushes out of the cell, because there is more water in the cell than in the solution.
Cell shrinks.
17. What is required for active transport to occur? Distinguish between endocytosis and exocytosis.
ATP (energy) is required ! endocytosis is cell eating or engulfing their food. Exocytosis is cells ejecting or “pooping” their
food. Both processes require energy and are types of active transport.
18. What is homeostasis? Give 2 examples of homeostasis.
The ability for an organism to maintain a stable, internal environment. Examples include sweating, shivering,
use of pH buffers, and hormones.
Information from Unit 1 on the Organic Compounds will also be on this Unit 2 test