BIOLOGY STUDY BOOK (2)
😇Chapter 6: Cells, Prokaryotes, Eukaryotes, and Cell Organelles
PART 1: WHAT IS A CELL?
Definition of a Cell
A cell is the smallest unit of life that can perform all necessary life processes.
Every living thing is made of cells.
This is one of the most important ideas in biology.
Cell Theory
The Cell Theory explains the basic ideas about cells.
It has three main statements:
1. All living things are made of one or more cells.
Examples:
A bacteria cell = one cell
A human body = trillions of cells
A tree = millions of cells
2. The cell is the basic unit of life.
Cells are the smallest structures that can:
Use energy
Maintain homeostasis
Reproduce
Respond to the environment
3. All cells come from pre-existing cells.
This means new cells are created from existing cells through cell division.
A cell does not appear from nothing.
PART 2: TWO MAIN TYPES OF CELLS
There are two major categories of cells:
Prokaryotic cells
Eukaryotic cells
The biggest difference:
Prokaryotes do NOT have a nucleus.
Eukaryotes DO have a nucleus.
PART 3: PROKARYOTIC CELLS
What Are Prokaryotes?
Prokaryotes are simple cells that do not contain a nucleus or membrane-bound organelles.
They are usually small and simple compared to eukaryotic cells.
Examples of Prokaryotes
The main examples are:
Bacteria
and
Archaea
Structure of Prokaryotes
Prokaryotes contain:
1. Cell Membrane
The cell membrane controls what enters and leaves the cell.
It protects the inside of the cell.
2. Cytoplasm
The cytoplasm is the jelly-like material inside the cell.
Many chemical reactions happen here.
3. Ribosomes
Ribosomes make proteins.
All cells have ribosomes.
4. DNA
Prokaryotes have DNA.
However, their DNA is not inside a nucleus.
Instead, it is located in an area called the:
Nucleoid Region
Important Prokaryote Facts
Prokaryotes:
Yes: Have DNA
Have ribosomes
Have a cell membrane
No:
Do not have a nucleus
Do not have membrane-bound organelles
PART 4: EUKARYOTIC CELLS
What Are Eukaryotes?
Eukaryotes are complex cells that contain a nucleus and membrane-bound organelles.
They are larger and more organized than prokaryotic cells.
Examples of Eukaryotes
Eukaryotic organisms include:
Humans
Animals
Plants
Fungi
Protists
Structure of Eukaryotic Cells
Eukaryotic cells contain:
Nucleus
Mitochondria
Endoplasmic reticulum
Golgi apparatus
Ribosomes
Cell membrane
Cytoplasm
Prokaryote vs Eukaryote Comparison
Memory Trick
Prokaryote
"Pro" = before
They are considered more ancient/simple.
No nucleus.
Eukaryote
"Eu" = true
"True nucleus"
They have a real nucleus.
PART 5: CELL ORGANELLES
What Are Organelles?
Organelles are specialized structures inside cells that perform specific jobs.
Think of organelles like organs in your body.
Your heart has a job.
Your lungs have a job.
Cell organelles also have jobs.
1. Nucleus
VERY IMPORTANT FOR YOUR TEST
What Is the Nucleus?
The nucleus is the control center of the cell.
It is surrounded by a membrane called the nuclear envelope.
Functions of the Nucleus
1. Stores DNA
The nucleus protects the cell's genetic information.
DNA contains instructions for making proteins.
2. Controls Cell Activities
The nucleus controls:
Growth
Metabolism
Protein production
Cell division
It sends instructions to the rest of the cell.
3. Controls Gene Expression
Gene expression means using DNA instructions to make proteins.
The nucleus controls which genes are used.
Nucleolus
Inside the nucleus is a smaller structure called the:
Nucleolus
The nucleolus makes:
Ribosomes
Remember:
Ribosomes = protein makers
Nucleus Memory Trick
Think:
Brain = control center of your body
Nucleus = control center of the cell
2. Ribosomes
Function:
Ribosomes make proteins.
Proteins are needed for:
Growth
Repair
Enzymes
Cell functions
Ribosomes can be found:
Floating in cytoplasm
Attached to rough ER
3. Endoplasmic Reticulum (ER)
The endoplasmic reticulum is a network of membranes inside the cell.
It helps make and transport molecules.
There are two types:
Rough ER
Smooth ER
PART 6: ROUGH ENDOPLASMIC RETICULUM
What Is Rough ER?
Rough ER is called "rough" because it has:
Ribosomes attached to its surface.
The ribosomes make it look bumpy.
Function of Rough ER
The main job of rough ER is:
Making and transporting proteins
Proteins made by rough ER can be:
Sent outside the cell
Inserted into cell membranes
Used inside the cell
Example:
A cell that produces lots of proteins will have lots of rough ER.
Example:
Cells that make digestive enzymes.
Rough ER Memory Trick:
ROUGH = RIBOSOMES
Both start with R.
Rough ER → Ribosomes → Proteins
PART 7: SMOOTH ENDOPLASMIC RETICULUM
What Is Smooth ER?
Smooth ER does NOT have ribosomes attached.
That is why it looks smooth.
Functions of Smooth ER
1. Makes Lipids
Smooth ER produces fats and other lipids.
2. Detoxification
Smooth ER helps break down harmful substances.
Especially in liver cells.
3. Stores Calcium
Calcium is important for:
Muscle movement
Cell signaling
Smooth ER Memory Trick:
Smooth = no bumps
No ribosomes
Makes lipids
Rough ER vs Smooth ER
TEST CONNECTIONS
Question:
What is the biggest difference between prokaryotes and eukaryotes?
Answer:
Prokaryotes lack a nucleus; eukaryotes have a nucleus.
Question:
What is the function of the nucleus?
Answer:
Stores DNA and controls cell activities.
Question:
Which organelle makes proteins?
Answer:
Ribosomes
Question:
Which ER makes proteins?
Answer:
Rough ER
Question:
Which ER makes lipids?
Answer:
Smooth ER
Question:
Why is rough ER called rough?
Answer:
It has ribosomes attached to it.
FLASHCARDS
Q: What is a cell?
A: The smallest unit of life capable of carrying out life processes.
Q: What are the three parts of cell theory?
A: All living things are made of cells, cells are the basic unit of life, and all cells come from existing cells.
Q: What is the main difference between prokaryotes and eukaryotes?
A: Prokaryotes lack a nucleus, while eukaryotes have a nucleus.
Q: Give examples of prokaryotes.
A: Bacteria and archaea.
Q: Give examples of eukaryotes.
A: Animals, plants, fungi, and protists.
Q: Do prokaryotes have DNA?
A: Yes, but it is not stored inside a nucleus.
Q: What is the nucleoid region?
A: The area where prokaryotic DNA is located.
Q: What is the function of the nucleus?
A: It stores DNA and controls cell activities.
Q: What does the nucleolus make?
A: Ribosomes.
Q: What do ribosomes make?
A: Proteins.
Q: Why is rough ER rough?
A: Because ribosomes are attached to it.
Q: What does rough ER make?
A: Proteins.
Q: What does smooth ER make?
A: Lipids.
Q: What are three functions of smooth ER?
A: Making lipids, detoxifying chemicals, and storing calcium.
CHAPTER 6 SUMMARY
Remember:
Cells are the basic unit of life.
Prokaryotes = no nucleus.
Eukaryotes = nucleus.
Nucleus = stores DNA + controls cell.
Nucleolus = makes ribosomes.
Ribosomes = make proteins.
Rough ER = ribosomes + proteins.
Smooth ER = lipids + detox + calcium.
Chapter 7: Microscopes, Magnification, Resolution, and Viewing Cells
This chapter is shorter than the others, but your teacher specifically listed:
Pros/Cons of Light Microscopes
So this is a high chance test topic. Let's make sure you can answer any version of the question.
PART 1: WHY DO WE NEED MICROSCOPES?
What Is a Microscope?
A microscope is a scientific instrument used to view objects that are too small to see with the naked eye.
The human eye can only see objects above a certain size.
Cells are usually too small to see without help.
Microscopes allow scientists to study:
Cells
Bacteria
Organelles
Tissues
Tiny structures
The History of Microscopes
Before microscopes were invented, scientists could not see cells.
In the 1600s, scientists began using early microscopes.
A scientist named:
Robert Hooke
observed slices of cork and saw tiny compartments.
He called them:
"Cells"
because they looked like small rooms.
Another scientist:
Antonie van Leeuwenhoek
used microscopes to observe living organisms, including bacteria.
He is often called the:
"Father of Microbiology"
PART 2: IMPORTANT MICROSCOPY TERMS
Magnification
Magnification is how much larger an object appears compared to its actual size.
Basically:
"How zoomed in are we?"
Example:
If a microscope magnifies something 400x:
The image appears 400 times larger than the real object.
Resolution
Resolution is the ability to see details clearly.
It describes how well a microscope can distinguish two objects that are close together.
Think:
Magnification = Bigger
Resolution = Clearer
Example:
A blurry picture can be enlarged, but making it bigger does not automatically make it clearer.
That is the difference between magnification and resolution.
Teacher Tip
A common test question:
"What is the difference between magnification and resolution?"
Answer:
Magnification increases the apparent size of an object, while resolution increases the ability to see details clearly.
PART 3: LIGHT MICROSCOPES
What Is a Light Microscope?
A light microscope uses visible light and glass lenses to magnify objects.
It is also called a:
Compound Light Microscope
because it uses multiple lenses.
How Does a Light Microscope Work?
Light passes through the sample.
Lenses bend the light.
The image becomes enlarged.
Your eye sees the magnified image.
What Can Light Microscopes See?
Light microscopes can view:
Cells
Tissues
Some bacteria
Living organisms
Examples:
Plant cells
Animal cells
Bacteria
Maximum Magnification
Most classroom light microscopes can magnify around:
1000x
Some can reach around:
2000x
PART 4: ADVANTAGES OF LIGHT MICROSCOPES
Advantage 1: Can View Living Cells
This is one of the biggest advantages.
Because light microscopes do not require extreme conditions, scientists can observe living organisms.
Examples:
Cells moving
Cell division
Organisms swimming
Advantage 2: Shows Color
Light microscopes can show natural colors or colors from stains.
This helps scientists identify structures.
Advantage 3: Less Expensive
Compared to electron microscopes, light microscopes are cheaper and easier to use.
Many schools use them.
Advantage 4: Easy to Prepare Samples
Samples usually do not require complicated preparation.
PART 5: DISADVANTAGES OF LIGHT MICROSCOPES
Disadvantage 1: Lower Magnification
Light microscopes cannot magnify as much as electron microscopes.
They cannot see extremely tiny structures clearly.
Disadvantage 2: Lower Resolution
Light microscopes have lower resolution.
This means tiny details may appear blurry.
Disadvantage 3: Cannot See Very Small Structures
They cannot clearly see:
Viruses
Many small organelles
Individual molecules
PART 6: ELECTRON MICROSCOPES
What Is an Electron Microscope?
An electron microscope uses beams of electrons instead of light to create images.
Electrons have much shorter wavelengths than visible light, allowing scientists to see much smaller details.
Types of Electron Microscopes
There are two main types:
1. Transmission Electron Microscope (TEM)
A TEM sends electrons through a thin sample.
It shows:
Internal structures
Very detailed images
2. Scanning Electron Microscope (SEM)
An SEM scans the surface of an object.
It shows:
Surface details
3D-like images
Advantages of Electron Microscopes
Much higher magnification
Much higher resolution
Can see very tiny structures
Disadvantages of Electron Microscopes
Cannot view living organisms
More expensive
Require special preparation
Images are usually black and white
Light Microscope vs Electron Microscope
PART 7: WHY CAN'T ELECTRON MICROSCOPES VIEW LIVING CELLS?
Electron microscopes require:
A vacuum environment
Special preparation
Samples that are usually preserved/dead
Living cells cannot survive these conditions.
PART 8: HOW MICROSCOPES RELATE TO CELL THEORY
Microscopes helped scientists discover cells.
Without microscopes, scientists would not know:
Cells exist
Organisms are made of cells
Cells have structures inside them
Microscopes provided evidence for the Cell Theory.
TEST QUESTIONS
Question:
What does magnification mean?
Answer:
How much larger an object appears compared to its actual size.
Question:
What does resolution mean?
Answer:
The ability to see details clearly.
Question:
Which microscope can view living cells?
Answer:
Light microscope.
Question:
Which microscope has higher magnification?
Answer:
Electron microscope.
Question:
Why can't electron microscopes view living cells?
Answer:
They require conditions that living cells cannot survive.
Question:
What is one disadvantage of a light microscope?
Answer:
It has lower magnification and resolution compared to electron microscopes.
Question:
What is one advantage of a light microscope?
Answer:
It can observe living cells.
FLASHCARDS
Q: What is a microscope?
A: A tool used to view objects too small to see with the naked eye.
Q: Why are microscopes important in biology?
A: They allow scientists to observe cells and structures that cannot be seen without magnification.
Q: What is magnification?
A: The process of making an object appear larger.
Q: What is resolution?
A: The ability to distinguish details clearly.
Q: What does a light microscope use?
A: Visible light and glass lenses.
Q: What can light microscopes observe?
A: Cells, tissues, and some living organisms.
Q: What is the biggest advantage of light microscopes?
A: They can view living cells.
Q: What is the biggest disadvantage of light microscopes?
A: They have lower magnification and resolution.
Q: What does an electron microscope use?
A: Beams of electrons.
Q: Which microscope has better resolution?
A: Electron microscope.
Q: Can electron microscopes view living cells?
A: No.
Q: Why are electron microscope images usually black and white?
A: They use electrons instead of visible light.
Q: What is the difference between magnification and resolution?
A: Magnification makes objects larger, while resolution makes details clearer.
PRACTICE QUESTIONS
Explain why microscopes are important for biology.
Compare light microscopes and electron microscopes.
Why is resolution important?
A scientist wants to observe a living cell moving. Which microscope should they use and why?
A scientist wants to see a virus. Which microscope should they use and why?
Explain two advantages and two disadvantages of light microscopes.
Explain the difference between magnification and resolution.
CHAPTER 7 SUMMARY
Remember:
Microscope = tool to see tiny objects
Magnification = makes bigger
Resolution = makes clearer
Light microscope:
Uses light
Can see living cells
Cheaper
Lower resolution
Electron microscope:
Uses electrons
Higher detail
Cannot see living cells
More expensive
Chapter 8: Cell Organelles, Cell Functions, and How Cells Work Together
PART 1: CELL ORGANIZATION
A cell is not just a random blob.
Cells are organized into different structures called:
Organelles
What Are Organelles?
Organelles are specialized structures inside cells that perform specific functions.
Each organelle has a specific job.
Think of a cell like a city:
Buildings = Organelles
Workers = Proteins
Power plants = Mitochondria
Shipping center = Golgi apparatus
Government = Nucleus
Every part works together.
PART 2: CELL MEMBRANE
What Is the Cell Membrane?
The cell membrane is the thin layer surrounding the cell.
It separates the inside of the cell from the outside environment.
Function of the Cell Membrane
The main function is:
Controlling what enters and leaves the cell
The cell membrane is selectively permeable.
What Does Selectively Permeable Mean?
It means:
The membrane allows some substances to pass through but blocks others.
Examples:
Oxygen can enter.
Waste products can leave.
Some large molecules cannot pass.
Cell Membrane Structure
The cell membrane is made mostly of:
Phospholipids
Phospholipids have:
A hydrophilic head
Hydrophobic tails
Remember:
Hydrophilic = likes water
Hydrophobic = avoids water
Because of this structure, the membrane forms a barrier around the cell.
PART 3: CYTOPLASM
What Is Cytoplasm?
The cytoplasm is the jelly-like material inside the cell.
It fills the space between organelles.
Functions of Cytoplasm:
1. Holds Organelles
Organelles float inside the cytoplasm.
2. Location of Chemical Reactions
Many cell processes happen in the cytoplasm.
Example:
Some steps of cellular respiration happen here.
PART 4: MITOCHONDRIA
What Are Mitochondria?
Mitochondria are organelles responsible for making energy.
They are often called:
"The powerhouse of the cell"
Function:
Mitochondria produce:
ATP
ATP is the main energy molecule used by cells.
How Do Mitochondria Make Energy?
They break down molecules like glucose using:
Cellular respiration
Glucose + Oxygen → ATP + Carbon dioxide + Water
Cells With Many Mitochondria
Cells that need lots of energy have many mitochondria.
Examples:
Muscle cells
Heart cells
Memory Trick:
Mitochondria = "Mighty energy makers"
PART 5: GOLGI APPARATUS
What Is the Golgi Apparatus?
The Golgi apparatus is the cell's:
Packaging and shipping center
Function:
The Golgi:
Modifies proteins and lipids
Packages them into vesicles
Sends them to where they need to go
Think:
Rough ER makes proteins → Golgi packages them → Cell uses or sends them
Memory Trick:
Golgi = "Gift wrapping and delivery"
PART 6: VACUOLES
What Are Vacuoles?
Vacuoles are storage organelles.
They store:
Water
Nutrients
Waste
Plant Cells
Plant cells have a:
Large central vacuole
Function:
Stores water and helps maintain cell shape.
Animal Cells
Animal cells may have smaller vacuoles.
PART 7: CHLOROPLASTS
What Are Chloroplasts?
Chloroplasts are organelles found in plant cells.
They contain:
Chlorophyll
Function:
Chloroplasts perform:
Photosynthesis
Photosynthesis converts:
Light energy
into
Chemical energy (glucose)
Equation:
Carbon dioxide + Water + Light → Glucose + Oxygen
Why Are Chloroplasts Important?
They allow plants to make their own food.
PART 8: CELL WALL
What Is the Cell Wall?
The cell wall is a rigid layer outside the cell membrane.
Found in:
Plants
Fungi
Bacteria
Animals do NOT have cell walls.
Function:
Provides support
Protects the cell
Helps maintain shape
Plant Cell vs Animal Cell
PART 9: HOW ORGANELLES WORK TOGETHER
Cells work like a system.
Example:
Making a Protein
Step 1:
DNA in nucleus contains instructions.
↓
Step 2:
Ribosomes read instructions and build proteins.
↓
Step 3:
Rough ER helps process and transport proteins.
↓
Step 4:
Golgi apparatus modifies and packages proteins.
↓
Step 5:
Protein is delivered where needed.
PART 10: ENDOMEMBRANE SYSTEM
The endomembrane system is a group of organelles that work together.
Includes:
Nuclear envelope
Endoplasmic reticulum
Golgi apparatus
Vesicles
Cell membrane
Their job:
Make, modify, and transport proteins and lipids.
PART 11: ORGANELLE MASTER TABLE
TEST QUESTIONS
Question:
What organelle is called the powerhouse of the cell?
Answer:
Mitochondria
Question:
What organelle packages proteins?
Answer:
Golgi apparatus
Question:
Where is DNA stored in eukaryotic cells?
Answer:
Nucleus
Question:
What organelle makes proteins?
Answer:
Ribosomes
Question:
What organelle makes ATP?
Answer:
Mitochondria
Question:
What organelle performs photosynthesis?
Answer:
Chloroplasts
Question:
What controls what enters and leaves the cell?
Answer:
Cell membrane
Question:
What is the function of vacuoles?
Answer:
Storage
FLASHCARDS
Q: What are organelles?
A: Specialized structures inside cells that perform specific jobs.
Q: What is the function of the cell membrane?
A: Controls what enters and leaves the cell.
Q: What does selectively permeable mean?
A: Allows some substances to pass while blocking others.
Q: What is cytoplasm?
A: Jelly-like material that holds organelles and is the site of many reactions.
Q: What do mitochondria do?
A: Produce ATP energy through cellular respiration.
Q: Why are mitochondria called the powerhouse of the cell?
A: Because they produce usable energy for the cell.
Q: What does the Golgi apparatus do?
A: Modifies, packages, and ships proteins and lipids.
Q: What do vacuoles store?
A: Water, nutrients, and waste.
Q: What do chloroplasts do?
A: Perform photosynthesis.
Q: What pigment is found in chloroplasts?
A: Chlorophyll.
Q: What is the function of a cell wall?
A: Provides support and protection.
Q: What is the difference between plant and animal cells?
A: Plant cells have cell walls, chloroplasts, and large vacuoles; animal cells do not.
PRACTICE QUESTIONS
Explain how the nucleus, ribosomes, rough ER, and Golgi work together.
Why do muscle cells contain many mitochondria?
Explain the difference between the cell wall and cell membrane.
Compare plant and animal cells.
What would happen if a cell could not produce ATP?
Explain why chloroplasts are important for plants.
Describe the job of each:
Nucleus
Ribosomes
Rough ER
Smooth ER
Golgi
CHAPTER 8 SUMMARY
Remember:
Nucleus = DNA + control center
Ribosomes = proteins
Rough ER = proteins
Smooth ER = lipids + detox
Golgi = package + ship
Mitochondria = ATP energy
Chloroplast = photosynthesis
Vacuole = storage
Cell membrane = controls movement
Cell wall = support
Chapter 9: Properties of Life + What Makes Something Alive?
This is your first test topic:
"Properties of Life and how to define Life with Biology terminology"
Let's master it
PART 1: WHAT IS LIFE?
Scientists do not define life by saying:
"Something that moves is alive."
Because:
Cars move
Rivers move
Clouds move
But they are not alive.
Instead, scientists identify living things by looking for specific characteristics.
These are called:
Characteristics of Life
or
Properties of Life
The 8 Characteristics of Life
Most biology classes teach that living things have these properties:
Made of cells
Reproduce
Have genetic material (DNA)
Grow and develop
Obtain and use energy
Respond to stimuli
Maintain homeostasis
Adapt and evolve
1. Living Things Are Made of Cells
The first rule of life:
All living things are made of one or more cells.
A cell is the smallest unit that can perform all functions of life.
Examples:
Bacteria:
One cell
Humans:
Trillions of cells
Plants:
Millions of cells
Two types of organisms:
Unicellular
"Uni" = one
Made of one cell.
Example:
Bacteria
Multicellular
"Multi" = many
Made of many cells.
Examples:
Humans
Animals
Plants
Test Question:
"What is the smallest unit of life?"
Answer:
Cell
2. Living Things Reproduce
Definition:
Reproduction is the process of creating new organisms.
Living things make offspring.
Two types of reproduction:
Sexual Reproduction
Two organisms contribute genetic information.
Example:
Humans
Asexual Reproduction
One organism produces offspring.
Example:
Bacteria dividing.
Why is reproduction important?
Because it allows a species to continue existing.
Important:
An individual organism does NOT have to reproduce to be alive.
Example:
A person who cannot have children is still alive.
The species must have the ability to reproduce.
3. Living Things Have DNA
Definition:
All living things contain genetic material.
The main genetic material is:
DNA
(Deoxyribonucleic Acid)
DNA contains instructions that tell cells how to function.
DNA controls:
Making proteins
Cell activities
Inherited traits
Example:
A plant's DNA contains instructions for:
Growing leaves
Making chlorophyll
Producing flowers
4. Living Things Grow and Develop
Growth:
Increasing in size.
Example:
A baby becoming an adult.
Development:
Changes that happen during an organism's life.
Example:
A caterpillar becoming a butterfly.
Growth requires:
Cell division
Energy
Genetic instructions
5. Living Things Use Energy
Definition:
Living things need energy to survive and perform life processes.
This process is called:
Metabolism
Metabolism:
The chemical reactions that occur inside an organism.
Energy is needed for:
Growth
Movement
Repair
Maintaining body temperature
Making molecules
Examples:
Plants:
Use sunlight through photosynthesis.
Animals:
Get energy by eating food.
6. Living Things Respond to Stimuli
Definition:
A stimulus is a change in the environment.
Living things respond to changes around them.
Examples:
Human:
Touch something hot → move hand away.
Plant:
Grow toward sunlight.
Bacteria:
Move toward nutrients.
Stimulus examples:
Temperature
Light
Sound
Chemicals
Touch
7. Living Things Maintain Homeostasis
This is a BIG biology word.
Definition:
Homeostasis is maintaining a stable internal environment despite changes outside the organism.
Basically:
Keeping things balanced.
Examples:
Humans maintain:
Body temperature
Blood sugar levels
Water balance
Example:
If you get hot:
Your body sweats.
Sweating helps cool your body.
That is homeostasis.
Why Is Homeostasis Important?
Cells only function correctly when conditions stay within certain limits.
Too much change can damage cells.
8. Living Things Adapt and Evolve
Adaptation:
A trait that helps an organism survive and reproduce in its environment.
Examples:
Polar bears:
Thick fur helps survive cold environments.
Cactus:
Stores water in dry environments.
Evolution:
The change in populations over many generations.
Important:
Individuals do not evolve.
Populations evolve.
BIOLOGY DEFINITION OF LIFE
A living thing is an organism that:
Is made of cells
Uses energy
Contains genetic material
Grows and develops
Reproduces
Responds to stimuli
Maintains homeostasis
Can adapt over time
TEST TRAPS
Question:
"Fire grows and uses energy. Is fire alive?"
Answer:
No.
Fire does not have cells or DNA.
Question:
"Are viruses alive?"
This is debated.
Why?
They have genetic material but cannot reproduce without a host cell.
Question:
"Does something need to move to be alive?"
No.
Plants are alive but do not move from place to place.
FLASHCARDS
Q: What are the characteristics of life?
A: Made of cells, reproduce, contain DNA, grow and develop, use energy, respond to stimuli, maintain homeostasis, and adapt.
Q: What is the smallest unit of life?
A: The cell.
Q: What is reproduction?
A: The process of creating new organisms.
Q: What is genetic material?
A: DNA that contains instructions for life.
Q: What is metabolism?
A: The chemical reactions that allow organisms to use energy.
Q: What is a stimulus?
A: A change in the environment that causes a response.
Q: What is homeostasis?
A: Maintaining a stable internal environment.
Q: What is an adaptation?
A: A trait that helps an organism survive and reproduce.
Q: What is evolution?
A: Change in populations over generations.
Q: Are plants alive even though they do not move?
A: Yes, because they have all characteristics of life.
PRACTICE QUESTIONS
List the eight characteristics of life.
Why is a cell considered the smallest unit of life?
Explain the difference between growth and development.
Why do organisms need energy?
Explain homeostasis with an example.
Why does having DNA make something living?
Explain the difference between adaptation and evolution.
CHAPTER 9 SUMMARY
Remember:
Cells = basic unit of life
DNA = instructions for life
Energy = powers life processes
Homeostasis = keeping balance
Stimulus = environmental change
Response = reaction to change
Adaptation = helpful trait
Evolution = population changes over time
Chapter 10: Practice Test + Ultimate Review
Your test format:
6 Multiple Choice
3 True/False
1 Fill in the Blank
4 Short Answer
Total: 14 questions
PART 1: THE BIGGEST THINGS TO MEMORIZE
1. Properties of Life
Living things:
Are made of cells
Reproduce
Contain DNA
Grow and develop
Use energy
Respond to stimuli
Maintain homeostasis
Adapt and evolve
2. Atom Basics
Remember:
Atomic Number = Protons
Always.
Mass Number = Protons + Neutrons
Formula:
Mass = P + N
Neutrons:
Mass Number - Atomic Number
Neutral Atom:
Protons = Electrons
Example:
Carbon:
Atomic number = 6
Protons = 6
Electrons = 6
Mass number = 12
Neutrons = 6
3. Chemical Bonds
Covalent Bond
= Sharing electrons
Example:
H₂O
Ionic Bond
= Transferring electrons
Example:
NaCl
Hydrogen Bond
= Weak attraction
Important in:
DNA
Water
4. DNA Bonds
SUPER IMPORTANT:
DNA backbone:
Covalent bonds
DNA strands:
Hydrogen bonds
5. Hydrophobic vs Hydrophilic
Hydrophilic
"Water-loving"
Polar
Mixes with water
Examples:
Sugar
Salt
Hydrophobic
"Water-fearing"
Nonpolar
Does not mix with water
Examples:
Oil
Fat
6. Density
Formula:
Density = Mass ÷ Volume
D = M/V
Water density:
1 g/mL
Less than water:
Float
Greater than water:
Sink
7. Carbon
Carbon is important because:
It forms 4 covalent bonds
This allows it to create millions of molecules.
Carbon is found in:
DNA
Proteins
Carbohydrates
Lipids
8. Macromolecules
Carbohydrates
Function:
Quick energy
Building block:
Monosaccharides
Lipids
Function:
Long-term energy storage
Also:
Cell membranes
Hydrophobic
Proteins
Building blocks:
Amino acids
Functions:
Enzymes
Structure
Transport
Defense
Nucleic Acids
Types:
DNA + RNA
Function:
Genetic information
9. DNA vs RNA
DNA bases:
A-T
C-G
RNA bases:
A-U
C-G
10. Denaturation
Definition:
A protein loses its shape and stops working.
Causes:
Heat
pH changes
Chemicals
11. Prokaryotes vs Eukaryotes
Prokaryotes:
No nucleus
Examples:
Bacteria
Eukaryotes:
Have nucleus
Examples:
Animals
Plants
Fungi
12. Cell Organelles
Memorize this table:
13. Microscope Review
Magnification
= Makes bigger
Resolution
= Makes clearer
Light Microscope
Advantages:
Can view living cells
Shows color
Cheaper
Disadvantages:
Lower magnification
Lower resolution
Cannot see tiny structures
Electron Microscope
Advantages:
Higher magnification
Higher resolution
Disadvantages:
Cannot view living cells
Expensive
PRACTICE TEST
MULTIPLE CHOICE
1. What determines the identity of an element?
A. Electrons
B. Neutrons
C. Protons
D. Energy level
Answer: C. Protons
2. What bond holds DNA base pairs together?
A. Ionic bond
B. Covalent bond
C. Hydrogen bond
D. Metallic bond
Answer: C. Hydrogen bond
3. Which organelle produces ATP?
A. Nucleus
B. Mitochondria
C. Ribosome
D. Golgi
Answer: B. Mitochondria
4. Which molecule stores genetic information?
A. Protein
B. Lipid
C. DNA
D. Carbohydrate
Answer: C. DNA
5. Which cell type lacks a nucleus?
A. Plant cell
B. Animal cell
C. Eukaryote
D. Prokaryote
Answer: D. Prokaryote
6. Which ER makes proteins?
A. Smooth ER
B. Rough ER
C. Golgi
D. Vacuole
Answer: B. Rough ER
TRUE/FALSE
1. Electrons determine how atoms bond.
True
2. Smooth ER contains ribosomes.
False
3. Electron microscopes can observe living cells.
False
FILL IN THE BLANK
The smallest unit of life is the ______.
Answer:
Cell
SHORT ANSWER PRACTICE
1. Explain the difference between prokaryotic and eukaryotic cells.
Answer:
Prokaryotic cells do not have a nucleus or membrane-bound organelles. Eukaryotic cells contain a nucleus and membrane-bound organelles.
2. Explain the difference between rough ER and smooth ER.
Answer:
Rough ER contains ribosomes and makes proteins. Smooth ER does not contain ribosomes and makes lipids while helping detoxify chemicals.
3. Explain why carbon is important in living organisms.
Answer:
Carbon can form four covalent bonds, allowing it to create many complex molecules needed for life.
4. Explain how DNA is held together.
Answer:
Covalent bonds hold the sugar-phosphate backbone together, while hydrogen bonds hold nitrogen base pairs between the two DNA strands.
LAST NIGHT BEFORE TEST CHECKLIST
If you only have 30 minutes:
Memorize:
Atomic number = protons
Density = mass ÷ volume
Covalent = share
Ionic = transfer
Hydrogen bonds = DNA strands
Covalent bonds = DNA backbone
DNA = stores information
RNA = makes proteins
Rough ER = proteins
Smooth ER = lipids
Nucleus = DNA/control
Mitochondria = ATP
Prokaryote = no nucleus
Eukaryote = nucleus
Light microscope = living cells
Resolution = clarity