7th Grade LIfe Science Final Exam Study Guide

What are the 5 steps to the scientific method?

1. Ask a question

2. Make a hypothesis

3. Do experiment

4. Analyse data

5. Form conclusion

What are variables?

Factors that can change or be changed in an experiment or study. They can be independent variables, control variables, or dependent variables.

What are independent variables?

Variables changed by the experimenter to determine what will happen to the dependent variable. Example: Amount of vinegar and baking soda.

What are dependent variables?

Variables that are affected by the independent variable in an experiment. They are the results that are measured during the experiment. Example: The height of the explosion

What are control variables?

Variables that are kept constant in an experiment to ensure that there are no other factors affecting the dependent variable other than the independent variable. Example: Light, Temperature, Precipitation…

What is a hypothesis?

A statement that predicts the relationship between an independent variable and a dependent variable. It is written in “If ____ then _____ because” format, where the "if" is the independent variable and the "then" is the dependent variable. Example: IF you combine 1 cup of vinegar and 2 cups of baking soda THEN the explosion will reach a height of 5 inches BECAUSE…

What type of microscope do we use?

A compound light microscope.

What is a compound light microscope?

A type of microscope that uses visible light and a series of lenses to magnify small objects or organisms.

What is #1?

An __**Eyepiece**__ is a lens at the top of a microscope that you look through. It also provides some magnification.

What is #2?

A __**Body Tube**__ is what connects the eyepiece to the objective lenses.

What is #3?

The __**Nose Piece**__ holds the __high__ and __low__ power objective __lenses__ that can be rotated to change the __magnification__.

What is #4?

The 3 __**Objective Lenses**__ provide magnification that ranges from __4__x to __40__x.

What is #5?

The __**Stage Clips**__ __hold__ the slide in place.

What is #6?

The __**Diaphragm**__ regulates the amount of __light__ on the specimen.

What is #7?

The __**Light Source**__ projects light __upward__ through the diaphragm, __specimen__, and __lenses__.

What is #8?

The __**Base**__ supports the __microscope.__

What is #9?

The __**Fine Adjustment Knob**__ moves the stage slightly to __sharpen__ the image.

What is #10?

The __**Coarse Adjustment Knob**__ moves the stage up and down for __focusing__.

What is #11?

The __**Stage**__ supports the __slide__ being viewed.

What is #12?

The __**Arm**__ is used to __support__ the microscope when carried.

What 2 parts of a compound light microscope provide magnification?

The ocular lens and the 3 objective lenses.

What is the magnification of the ocular lens?

10x.

What is the magnification of the 3 objective lenses from lowest to highest?

4x, 10x, and 40x.

What is the magnification of the 3 objective lenses and the ocular lens from lowest to highest?

40x, 100x, and 400x.

When something is placed under a compound light microscope, how will it look? (rotated 90° to the left, right-side up, upside down…)

It will look upside down.

\*What is a virus?

A non-living particle consisting of a core of hereditary material, surrounded by a protein coat.

How do viruses reproduce?

The virus attaches and enters the cell, this now becomes the host cell. Once inside it takes over the functions of the cell and redirects it to make new virus parts. New viruses are assembled inside the cell. When the cell is full it bursts and releases the new viruses, this kills the host cell.

\*Where do viruses reproduce?

Inside the cell.

\*How are viruses similar to living things?

They have the ability to multiply.

How are viruses different from living things?

1\. Viruses are not made up of cells.

2\. Viruses do not use energy to grow.

3\. Viruses cannot take in food or make food.

4\. Viruses cannot produce waste.

Besides humans, what are some other organisms that viruses can infect?

Viruses can infect animals, plants, bacteria, fungi, and protists.

Why does a virus only invade a specific type of cell?

Because the outer protein coat acts like a “lock-and-key” system which is very specific so each virus will attach to only one or a few types of cells.

Virus Diagram: What is A and B?

A = Outer protein coat that gives protection and aids in attaching to the host cell.

B = Genetic material which Contains the directions for making new viruses.

\*What is your body's defense system? And what does it fight against?

The Immune System fights against disease-causing organisms, malfunctioning cells, and foreign particles.-

What are the three lines of defense in the immune system?

1. Physical and chemical barriers

2. The inflammatory response

3. The immune response

\*What are the physical and chemical barriers in the immune system?

Chemical = sweat, tears, saliva, mucus, and stomach acid.

Physical = skin, snot, ear wax, eyelash, and nose/ear hair.

\*What is the inflammatory response?

Swelling, redness, warmth, pain , white blood cells (puss).

\*What is the immune response?

The production and release of antibodies (proteins that latch onto damage clump and slow foreign particles).

What is a vaccine and what does it do?

A weekend bacteria or virus that is purposely introduced to your immune system with the intention of producing immunity through the form of recognition.

What are the levels of organization from largest to smallest? And what does it mean?

1. Organisms

2. Organ Systems

3. Organs

4. Tissues

5. Cells

It means that while not all cells make up tissue all tissues are composed of cells Ext...

What are cells? (Not the type of phone)

It the microscopic structure for all living things.

What are some examples of cells? Name at least one.

Red blood cells, nerve cells, muscle cells, skin cells, bone cells, and more…

What are tissues? (The answer is not to blow your nose)

A connecting group of cells that do the same thing.

What are some examples of tissues? Name at least one.

Muscle tissue, nervous tissue, connective tissue, epithelial tissue, and more…

What are organs? (Not the instrument)

A connecting group of tissues that do the same thing.

What are some examples of organs? Name at least one.

Heart, lungs, liver, stomach, brain, kidneys, intestines, and more…

What are organ systems?

A connecting group of organs that do the same thing.

What are some examples of organ systems? Name at least one.

The digestive system, the nervous system, the skeletal system, the muscular system, and more…

What are organisms?

a connecting group of Oregon systems that do the same thing.

What are some examples of organisms? Name at least one.

Mammals, fish, humans, plants, bacteria, and more.

What are the three parts to cell theory?

1. All organisms are composed of one or more cells

2. The cell is the basic unit of structure and organization in organisms

3. All cells come from pre-existing cells

Why is cell theory important?

It tells us what makes up all life.

What is a prokaryotic cell?

A cell before the development of a nucleus.

What is an eukaryotic cell?

A cell with a true nucleus.

What 8 things do prokaryotic and eukaryotic cells have in common?

• DNA

• Cell (plasma) membrane

• Ribosomes

  • Simple in Prokaryotic, complex in Eukaryotic

• Cytoplasm

• Allow the flow of nutrients and wastes to enter and leave the cell

• Have similar metabolic ( life processes) like photosynthesis and respiration

• Require a supply of energy

• Made from the same basic chemicals

  • Carbohydrates, proteins, nucleic acid, fats, minerals, and vitamins

What are the 2 major differences between prokaryotic and eukaryotic cells?

Structure

• Eukaryotic cells have a nucleus, prokaryotic cells don’t

Age

• Prokaryotic cells are about 2 billion years older than eukaryotic cells

What is this a Microscopic image of? (Plant/Animal Cell)

Plant Cells.

What is this a Microscopic image of? (Plant/Animal Cell)

Animal Cells.

What type of cell is this an image of?

Label each organelle.

A plant cell.


1. Cytoskeleton
2. Golgi body
3. Vacuole
4. Nucleolus
5. Nucleus
6. Smooth endoplasmic reticulum
7. Ribosomes
8. Rough endoplasmic reticulum
9. Cell wall
10. Chloroplast
11. Cell membrane
12. Mitochondria
13. Peroxisome

What type of cell is this an image of?

Label each organelle.

An animal cell.


1. Centrioles
2. Nucleolus
3. Nucleus
4. Lysosomes
5. Smooth endoplasmic reticulum
6. Golgi body
7. Rough endoplasmic reticulum
8. Ribosomes
9. Cell membrane
10. Mitochondria
11. Cytoskeleton

What and where is the Cell wall?

Provides structure and contains turgor pressure. It surrounds the cell. It is only in plant cells.

What and where is the Cell membrane?

Controls the movement of substances in and out of the cell. In an animal cell, it surrounds the cell and in plant cell, it's in been the cell wall and the cytoplasm.

What and where are the Centrioles?

Create the spindle fibers for cell division. They are located in the cytoplasm. They are only in animal cells.

What and where is the Golgi body?

Modifies sorts and packages substances in and out of the cell. It is located relatively close to the nucleus in the endoplasmic reticulum for both plant and animal cells.

What and where is the Vacuole?

Isolates material that might harm the cell. It is located in the cytoplasm. It is only in plant cells.

What and where is the Nucleus?

Stores the cell’s hereditary material and coordinates the cells activity. located in the cytoplasm for both plants and animal cells.

What and where is the Chloroplast?

Does photosynthesis. Is it is in the cytoplasm. It is only in plant cells.

What and where are the Ribosomes?

Make protein. Located In the cytoplasm for both plant and animal cells.

What and where is the Mitochondria?

Produces energy, stores calcium, generates heat, controls growth, and controls death. Located in the cytoplasm for both animal and plant cells.

What and where is the Smooth endoplasmic reticulum?

Produces carbohydrates. Near the cell membrane in the cytoplasm and adjacent to the nucleus for both plant and animal cells.

What and where is the Rough endoplasmic reticulum?

Makes protein. Near the cell membrane in the cytoplasm and adjacent to the nucleus for both plant and animal cells.

What and where is the Nucleolus?

Builds ribosomes. Located in the center of the nucleus for both plant and animal cells.

What and where is the Cytoskeleton?

Supports this cell (cell bones) and gives the cell shape. located throughout the whole cell In both plant and animal cells.

What and where are the Lysosomes?

Breaks down molecules to be reused. Located in the cytoplasm. Only in animal cells.

What four cellular processes did we learn about?

1. Cellular respiration

2. Photosynthesis

3. diffusion

4. Osmosis

What is cellular respiration?

The breakdown of food to make energy.

What type of cells does cellular respiration take place in?

All types.

Where in a cell does cellular respiration take place?

The Mitochondria.

What is this an equation for? And what does everything represent?

Cellular respiration, Glucose + oxygen → carbon dioxide + water.

What is photosynthesis?

The process of changing light energy to chemical energy stored as sugar.

What type of cells does photosynthesis take place in?

Mostly Plant cells.

Where in a cell does photosynthesis take place?

The chloroplast.

What is this an equation for? And what does everything represent?

Photosynthesis, Carbon Dioxide + Water (+ light energy)→ Glucose + Oxygen

What is osmosis?

The movement of water molecules from a highly concentrated area to a less concentrated area through a selectively permeable membrane.

What type of cells does osmosis take place in?

All types.

Where in a cell does osmosis occur?

The cell membrane.

What is diffusion?

The movement of molecules from an area of higher concentration to an area of lower concentration through a selectively permeable membrane.

What type of cells does diffusion take place in?

All types.

Where in a cell does diffusion occur?

The cell membrane.

What is a selectively permeable membrane?

A membrane that will allow certain things to pass in and out of the cell. Example: Cell membrane

What is passive transport?

When materials can pass in or out of a cell without using any of its energy. Example: Osmosis and Diffusion

What is active transport?

When a cell has to use its own energy to pass something in or out of the it.

What 3 processes are in the cell cycle and what happens during them?

1. Interphase - growth

2. Mitoses - division of nucleus

3. Cytokinesis - division of cytoplasm

What's the acronym for the cell cycle?

I-PMAT-C

What are all the parts of the cell cycle?

1. Interphase

2. Mitosis

   1. Prophase

   2. Metaphase

   3. Anaphase

   4. Telophase

3. Cytokinesis

What happens during Interphase?

DNA is replicated.

What happens during Prophase?

Mitosis Part 1:

1. Nuclear membrane disappears

2. Chromatin coils up into chromosomes

3. Spindles form

4. Centrioles move to opposite ends

What happens during Metaphase?

Mitosis Part 2:

1. Chromosomes line-up in the center

2. Each centromere becomes attached to a spindle fiber

What happens during Anaphase?

Mitosis Part 3:

1. Centromere splits

2. Chromosomes separate

3. Strands move away toward opposite ends

What happens during Telophase?

Mitosis Part 4:

1. Nuclear membrane reappears around each set of chromosomes

2. Chromosomes uncoil back to chromatin

3. Spindles dissolve