Independent and Dependent Variables Scenarios

(manipulated and responding).

download pdf

For each, identify the independent (manipulated) and dependent (responding) variable.

1.  A cow is given a growth hormone and then compared to another cow that was not given a growth hormone.  Both cows were weighed at 2 years.

cow

2.  Mosquito repellent is sprayed on one arm and the other arm is not sprayed.  The number of mosquito bites is counted after 2 hours.

mosquito

3.  One grape is placed in tap water and another grape is placed in salt water. The change in their mass is measured after a day.

scale

4.Two different cars are traveling at 60 mph.  At a certain point, both cars slam on the brakes.  The distance it takes for each car to stop is then measured.

car

5. Pillbugs are placed in a container where they have a choice of a wet or a dry environment.  Researchers record how much time was spent on each side.

pillbugs

6.  A stapler is used to staple 100 papers, it jams 5 times during the trial. A different brand of stapler performs the same test; it jams 22 times.

stapler

7. Cockroaches are exposed to a pesticide.  After 3 hours, 95% of the insects are dead.

cockroach

8. Two plants are grown using the same light and pots.  One plant is given water that has been microwaved and the other plant is given regular tap water.  Their height is measured after 2 weeks.

plants

9. The blood pressure of a soldier is measured while he is resting.  The soldier is then exposed to a stressful environment and his blood pressure is measured again.

stethoscope

10.  An apple is cut into slices. Half of the slices are sprayed with lemon juice. All slices are stored in a sealed plastic bag. After 4 days, they are observed to see how brown they turned. 

apple

11. The respiration rate of a goldfish is measured. The goldfish is then placed in cold water and the respiration rate is measured again. 

fish

12. Bacteria are grown in a petri dish. One side of the dish is sprayed with an antibiotic.  After a week, the number of bacteria colonies are counted on each side.

bacteria

Other Resources on the Scientific Method

Variables with Simpsons  – read stories involving characters from the Simpsons and determine the independent and dependent variables

Beriberi and Penicillin  – a short story on the discovery of penicillin and that Beriberi was caused by a vitamin deficiency

Discoveries in Science  – focus on Pasteur’s experiment and other discoveries in science

Scientific Method Scenarios  – activity where students are given a question and must design an experiment and identify variables

Back Home

  • Science Notes Posts
  • Contact Science Notes
  • Todd Helmenstine Biography
  • Anne Helmenstine Biography
  • Free Printable Periodic Tables (PDF and PNG)
  • Periodic Table Wallpapers
  • Interactive Periodic Table
  • Periodic Table Posters
  • How to Grow Crystals
  • Chemistry Projects
  • Fire and Flames Projects
  • Holiday Science
  • Chemistry Problems With Answers
  • Physics Problems
  • Unit Conversion Example Problems
  • Chemistry Worksheets
  • Biology Worksheets
  • Periodic Table Worksheets
  • Physical Science Worksheets
  • Science Lab Worksheets
  • My Amazon Books

Biology Worksheets, Notes, and Quizzes (PDF and PNG)

Biology Notes, Worksheets, and Quizzes

This is a collection of free biology worksheets, notes, handouts, slides, study guides and quizzes. Most content targets high school, AP biology, genetics, anatomy/physiology, immunology, and biology 101 and 102 in college. There is also biochemistry and physics for biologists. However, some resources are at the grade school and middle school level.

The files are PDF, PNG, JPG, and formats using Google Apps for Google Classroom. Most of the time, these formats are interchangeable. So, if you see something you like, but want a different format, just let us know. Print these resources, make transparencies and slides, etc.

In the interest of quick load time, not all of the images are shown. If you’d rather see them all, just contact us!

Biochemistry

Understanding the Differences Between RNA and DNA - Worksheet

[ Google apps worksheet ][ worksheet PDF ][ answers PDF ][ worksheet PNG ][ answers PNG ]

Enzymes Worksheet

Enzymes Definitions

[ Google Slides worksheet ][ worksheet PDF ][ answers PDF ][ worksheet PNG ][ answers PNG ]

  • 20 Amino Acids [ PNG ][ PDF ]
  • Amino Acid Side Chains [ PNG ][ PDF ]
  • Identifying Type of Biological Macromolecules [ Google Slides worksheet ][ worksheet PDF ][ answers PDF ][ worksheet PNG ][ answers PNG ]
  • Disaccharide Examples [ PNG ]
  • Products of Photosynthesis [ JPG ]
  • Anabolism vs Catabolism [ PNG ]
  • 3 Parts of a Nucleotide [ PNG ]
  • Fermentation Definition and Examples [ PNG ]

General and Cell Biology

Major Organelles and Their Function Worksheet

Organelles and Their Functions

Parts of a Plant Cell Worksheet

Parts of a Plant Cell

Anatomy of a Chloroplast Worksheet

Label Parts of a Chloroplast

[ Google Apps worksheet ][ worksheet PDF ][ answers PDF ][ worksheet PNG ][ answers PNG ]

Anatomy of the Mitochondria Worksheet

Label Parts of a Mitochondria

Animal Cell Worksheet

Label the Animal Cell

[ Google Apps worksheet ][ worksheet PDF ][ worksheet PNG ][ answers PNG ]

Prokaryotes vs Eukaryotes Worksheet

Prokaryotes vs Eukaryotes Worksheet

Stages of the Cell Cycle Worksheet

Steps of the Cell Cycle

Stages of Mitosis Worksheet

Steps of Mitosis

Membrane Transport Worksheet

Membrane Transport Terms and Definitions

Membrane Transport Worksheet 2

Membrane Transport Worksheet #2

The Plasma Membrane Worksheet

The Plasma Membrane

Bacterial Cell Anatomy Worksheet

Label a Bacterial Cell

  • Label a Bacteriophage [ Google Apps worksheet ][ worksheet PDF ][ worksheet PNG ][ answers PNG ]
  • Evidence of Evolution Worksheet [ Google Apps worksheet ][ Worksheet PDF ][ Worksheet PNG ][ Answers PNG ]
  • Evolutionary Processes Worksheet [ worksheet Google Apps ][ worksheet PDF ][ worksheet PNG ][ answers PNG ]
  • Major Receptor Families [ Google Apps worksheet ][ worksheet PDF ][ worksheet PNG ][ answers PNG ]
  • Label a Bacterial Cell Membrane ( E. coli ) [ Google Apps worksheet ][ worksheet PDF ][ worksheet PNG ][ answers PNG ]

Anatomy and Physiology

These worksheets are only a portion of the available anatomy and physiology worksheets. Human anatomy and physiology worksheets have their own section.

Anatomy of the Heart Worksheet

Label the Heart

Anatomy of the Eye Worksheet

Label the Eye

[ Google Apps worksheet ][ worksheet PDF ][ answers PDF ][ worksheet PNG ]

Types of Blood Cells Worksheet

Types of Blood Cells

[ worksheet Google Apps ][ worksheet PDF ][ worksheet PNG ][ answers PNG ]

The Main Anterior Muscles Worksheet

Label the Muscles

[ worksheet PDF ][ worksheet PNG ][ answers PNG ]

Anatomy of the ear worksheet

Label the Ear

[ Google Apps worksheet ][ Worksheet PDF ][ Worksheet PNG ][ Answers PNG ]

Anatomy of the Lungs Worksheet

Label the Lungs

Anatomy of a Kidney Worksheet

Label the Kidney

Anatomy of the Liver Worksheet

Label the Liver

Anatomy of the Large Intestine Worksheet

Label the Large Intestine

Anatomy of the Stomach Worksheet

Label the Stomach

[ Google Apps worksheet ] [Worksheet PDF ][ Worksheet PNG ][ Answers PNG ]

External Nose Anatomy Worksheet

External Nose Anatomy

[ Worksheet PDF ][ Worksheet Google Apps ][ Worksheet PNG ][ Answers PNG ]

Anatomy of the Nose Worksheet

Parts of the Nose

The Skeletal System Worksheet

Label Bones of the Skeleton

Anatomy of a Lymph Node - Worksheet

Label the Lymph Node

Anatomy of of the Brain Worksheet

Label the Parts of the Brain

Lobes of the Brain Worksheet

Label the Lobes of the Brain

Anatomical Directions of the Brain Worksheet

Brain Anatomical Sections

Arteries of the Brain Worksheet

Arteries of the Brain

Anatomy of the Pancreas Worksheet

Label the Pancreas

Anatomy of the Spleen Worksheet

Label the Spleen

The Digestive System Worksheet

Label the Digestive System

The Respiratory System Worksheet

Label the Respiratory System

Anatomy of a Neuron Worksheet

Parts of a Neuron

Lip Anatomy Worksheet

Label the Lips

Anatomy of the Skin Worksheet

Label the Skin

The Circulatory System Worksheet

Label the Circulatory System

The Excretory System Worksheet

The Urinary Tract

[ Worksheet PDF ][ Worksheet Google Apps ][ Worksheet PNG ][ Answer Key PNG ]

Anatomy of the Bladder Worksheet

The Bladder

  • The Female Reproductive System [ worksheet PDF ][ worksheet Google Apps ][ worksheet PNG ][ answers PNG ]

Parts of a Flower Worksheet

Parts of a Flower

Anatomy of an orchid Worksheet

Label the Orchid Plant

[ Worksheet PDF ][ Worksheet Google Apps ][ Worksheet PNG ] [Answer Key PNG ]

Parts of an orchid flower Worksheet

Parts of an Orchid Flower

Parts of a monocot seed Worksheet

Parts of a Monocot Seed

Parts of a fern Worksheet

Parts of a Fern

Parts of a tree trunk Worksheet

Parts of a Tree Trunk

Parts of a Tree Worksheet

Parts of a Tree

[ worksheet PDF ][ worksheet Google Apps ][ worksheet PNG ][ answers PNG ]

Basic Anatomy of a Mushroom Worksheet

Parts of a Mushroom

Parts of a Shark Worksheet

Label the Shark

Anatomy of a Fish Worksheet

Label the Fish

Parts of a Bird Worksheet

Parts of a Bird

Basic Anatomy of a Bird Worksheet

Bird Anatomy

Life Cycle of a Frog Worksheet

Frog Life Cycle

Basic Mosquito Anatomy Worksheet

Parts of a Mosquito (Insect)

biology variables worksheet

Bones of the T. rex Skull

[ worksheets PDF ][ worksheet Google Slides ][ worksheet PNG ][ answers PNG ]

biology variables worksheet

Holes of the T. rex Skull

  • Label the T. rex Skeleton [ worksheets PDF ][ worksheet Google Slides ][ worksheet PNG ][ answers PNG ]
  • Label Human Teeth [ Worksheet PDF ][ Worksheet Google Apps ][ Worksheet PNG ][ Answer Key PNG ]
  • Monocot vs Dicot Seeds [ worksheet PDF ][ worksheet Google Slides ][ worksheet PNG ][ answers PNG ]
  • Label the Moss [ worksheet PDF ][ worksheet Google Slides ][ worksheet PNG ][ answers PNG ]
  • Diagram of the Human Eye [ JPG ]

Use a completed worksheet as a study guide.

Cells of the Immune System Worksheet

Cells of the Immune System

Immune Cell Functions - Worksheet 1

Immune Cell Functions

[ worksheet Google Apps ][ worksheet PDF ][ worksheet PNG #1][ answers PNG #1][ worksheet PNG #2][ answers PNG #2]

Methods to Study Virus Structures Worksheet

Methods to Study Virus Structures

[ worksheet Google Slide ][ worksheet PDF ][ worksheet PNG ][ answers PNG ]

Icosahedral Virus Capsids Worksheet

Icosahedral Virus Capsids

Human DNA Viruses Worksheet

Human DNA Viruses

Human RNA Viruses Worksheet

Human RNA Viruses

This is selection of worksheets relating to DNA, RNA, transcription, translation, genetic crosses, plasmid mapping, etc. See the full collection of genetics worksheets if you’re don’t see what you need.

DNA Replication Worksheet

DNA Replication

Types of Mutations Worksheet

Types of Mutations

Monohybrid Cross - Worksheet #1

Monohybrid Cross Worksheet #1

Monohybrid Cross - Worksheet #2

Monohybrid Cross Worksheet #2

Monohybrid Cross - Worksheet #3

Monohybrid Cross Worksheet #3

Monohybrid Cross 4 Multiple Alleles - Worksheet

Monohybrid Cross #4 – Multiple Alleles

  • Monohybrid Cross Worksheet #5: Multiple Alleles [ worksheet Google Apps ][ worksheet PDF ][ worksheet PNG ][ answers PNG ]

Monohybrid Cross 6 Sex-Linked Inheritance Worksheet

Monohybrid Cross #6 – Sex-Linked Inheritance

Sex-Linked Inheritance Worksheet

Monohybrid Cross #7 – Sex-Linked Inheritance

Dihybrid Cross - Worksheet #1

Dihybrid Cross Worksheet #1

Dihybrid Cross 2 - Worksheet (8.5 × 11 in)

Dihybrid Cross Worksheet #2

Dihybrid Cross 3 - Student (8.5 × 11 in)

Dihybrid Cross Worksheet #3

Dihybrid Cross 4 - Student (8.5 × 11 in)

Dihybrid Cross Worksheet #4

Dihybrid Cross 5 Epistasis Worksheet

Dihybrid Cross #5 – Epistasis

Dihybrid Cross 6 Epistasis Worksheet

Dihybrid Cross #6 – Epistasis

Incomplete Dominance - Worksheet #1

Incomplete Dominance Worksheet #1

Incomplete Dominance - Worksheet #2

Incomplete Dominance Worksheet #2

Natural Selection Worksheet

Natural Selection Worksheet

Convergent vs. Divergent Evolution Worksheet

Convergent vs Divergent Evolution Worksheet

Pedigree Worksheet 1 Worksheet

Intro to Pedigrees Worksheet #1

Pedigree Worksheet 2 (Student)

Pedigrees/Genealogy Worksheet #2

Pedigree Worksheet 3 (Student)

Pedigrees/Genealogy Worksheet #3 – X-Linked Dominant Traits

Pedigree Worksheet 4 X-Linked Recessive Traits (Student)

Pedigrees/Genealogy Worksheet #4 – X-Linked Recessive Traits

Pedigree Worksheet 5 Autosomal Dominant Traits (Student)

Pedigrees/Genealogy Worksheet #5 – Autosomal Dominant Traits

biology variables worksheet

Pedigrees/Genealogy Worksheet #6 – Autosomal Recessive Traits

Pedigree Worksheet 7 (Student)

Pedigrees/Genealogy Worksheet #7 – Comprehension Skills

Pedigree Worksheet 8 Worksheet

Pedigrees/Genealogy Worksheet #8 – Identifying Inheritance Patterns

Autosomal vs Sex-Linked Inheritance Worksheet

Autosomal vs Sex-Linked Inheritance

Plasmid Mapping Worksheet 1 (Student)

Plasmid Mapping

  • Genotype vs Phenotype [ PNG ]
  • Genetic Codon Chart [ PNG ][ PDF ]
  • RNA vs DNA [ JPG ]

Use labelled diagrams as study guides.

Ecosystem Worksheet 1

Ecosystems Worksheet

Levels of organization in ecology Worksheet

Levels of Organization (Ecosystem)

Levels of Primary Succession Worksheet

Primary Succession

Levels of Secondary Succession Worksheet

Secondary Succession

Parts of the Insect Worksheet

Label the Insect

Anatomy of a Bee Worksheet

Label the Bee

Life Cycle of a Chicken Worksheet

Chicken Life Cycle (Basic)

Life Cycle of a Bird Worksheet

Bird Life Cycle (Basic)

Frog Life Cycle Worksheet

Butterfly Life Cycle

  • Biotic and Abiotic Factors [ worksheet PDF ][ worksheet Google Apps ][ worksheet PNG ][ answers PNG ]
  • Kingdoms of Life Graphic [ PNG ]
  • Autotroph vs Heterotroph Graphic [ PNG ]
  • Commensalism Definition and Examples [ PNG ]
  • Difference Between Butterflies and Moths [ JPG ]
  • Difference Between Bugs and Insects [ PNG ]

Parasitology

Schistosome Life Cycle Worksheet

Schistosome Life Cycle

Adult Schistosome Worksheet

Schistosome Anatomy

  • Giardia Life Cycle [ worksheet Google Apps ][ worksheet PDF ][ worksheet PNG ][ answers PNG ]

Physical Science for Biology

There is also an entire section devoted to physical science worksheets and study guides.

  • Adhesion vs Cohesion Graphic [ PNG ]
  • What Is Entropy? [ PNG ]
  • Freezing Point of Water [ PNG ]

Biology Labs

  • How to Extract DNA From a Banana [ PNG ]

Biology Word Search Puzzles

  • DNA Replication Word Search
  • Gel Electrophoresis Word Search
  • Citrus Fruits
  • General Biology Word Search Puzzle [ PNG ]
  • Life Science Word Search [ PNG ][ PDF ]
  • Cell Biology Word Search [ PNG ][ PDF ]
  • Amino Acid Word Search [ PNG ][ PDF ]
  • Biome Word Search [ PNG ][ PDF ]
  • Environmental Science Word Search [ PNG ][ PDF ]
  • Photosynthesis Word Search [ PNG ]
  • Human Skeleton Bones Word Search [ PNG ]
  • Dinosaur Word Search [ PNG ][ PDF ]
  • Different Dinosaur Word Search [ PNG ][ PDF ]
  • Wild Cats Word Search [ PNG ][ PDF ]
  • Shark Word Search [ PNG ]
  • Trees Word Search [ PNG ][ PDF ]
  • Flowers Word Search [ PNG ][ PDF ]
  • Butterfly Word Search [ PNG ][ PDF ]
  • Genetics Word Search [ PNG ][ PDF ]

Miscellaneous Biology Notes and Resouces

  • How Long Can Germs Live on Surfaces? [ PNG ]
  • 10 Radioactive Foods [ PNG ]
  • Examples of Organic Compounds [ PNG ]

Biology Notes Terms of Use

You are welcome to print these resources for personal or classroom use. They may be used as handouts or posters. They may  not  be posted elsewhere online, sold, or used on products for sale.

This page doesn’t include all of the assets on the Science Notes site. If there’s a table or worksheet you need but don’t see, just let us know.

Related Posts

Library homepage

  • school Campus Bookshelves
  • menu_book Bookshelves
  • perm_media Learning Objects
  • login Login
  • how_to_reg Request Instructor Account
  • hub Instructor Commons

Margin Size

  • Download Page (PDF)
  • Download Full Book (PDF)
  • Periodic Table
  • Physics Constants
  • Scientific Calculator
  • Reference & Cite
  • Tools expand_more
  • Readability

selected template will load here

This action is not available.

Biology LibreTexts

Scientific Method

  • Last updated
  • Save as PDF
  • Page ID 23832
  • Katherine Harris
  • Hartnell College

\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

\( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)

\( \newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\)

( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\)

\( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)

\( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\)

\( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)

\( \newcommand{\Span}{\mathrm{span}}\)

\( \newcommand{\id}{\mathrm{id}}\)

\( \newcommand{\kernel}{\mathrm{null}\,}\)

\( \newcommand{\range}{\mathrm{range}\,}\)

\( \newcommand{\RealPart}{\mathrm{Re}}\)

\( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)

\( \newcommand{\Argument}{\mathrm{Arg}}\)

\( \newcommand{\norm}[1]{\| #1 \|}\)

\( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\AA}{\unicode[.8,0]{x212B}}\)

\( \newcommand{\vectorA}[1]{\vec{#1}}      % arrow\)

\( \newcommand{\vectorAt}[1]{\vec{\text{#1}}}      % arrow\)

\( \newcommand{\vectorB}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

\( \newcommand{\vectorC}[1]{\textbf{#1}} \)

\( \newcommand{\vectorD}[1]{\overrightarrow{#1}} \)

\( \newcommand{\vectorDt}[1]{\overrightarrow{\text{#1}}} \)

\( \newcommand{\vectE}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{\mathbf {#1}}}} \)

1. Description of the Scientific Method

One of the goals of science is to come up with explanations about how the natural world (all the things we see or experience) functions. Although there are other systems for understanding and explaining the world around us (such as religion and traditional beliefs) science differs from these in that scientific explanations are based on laws of nature. Laws of nature are patterns in nature that are  objective  (do not depend on faith, authority, or opinion), are  testable  (can be demonstrated with experiments), and are  consistent  (the same conditions produce the same results). 

The 4 Steps of the Scientific Method

To learn about the natural world, scientists use a four step procedure called the  scientific method . The four steps of the scientific method are listed below. To help illustrate the scientific method, an example that an entomologist (a biologist who specializes in insects) might use is given in italics below each step.

Step 1: Observations & Questions

Observe something in the natural world and ask a question about how it works. The part of the natural world that is observed and investigated is usually the area that the scientist specializes in. An entomologist for example, would ask questions about how insects function.

“The life cycle of a fruit fly is about 30 days (at 29 degrees Celsius). How do changes in temperature affect the life cycle of a fruit fly?”  

Step 2: Hypothesis

Make a hypothesis (an educated guess) which attempts to answer the question. A useful hypothesis is a  testable  statement.

“Decreasing the temperature of a fruit fly's environment will increase the time it takes the fruit fly to complete its life cycle.”

Step 3: Experiment

Design and carry out an experiment that is capable of testing the hypothesis. In other words, the experiment must be designed so that it will produce results that either clearly support or clearly falsify (disprove) the hypothesis. It helps to use “If-Then” predictions based on your hypothesis.

“Place 100 fruit flies at 18 degrees Celsius for one generation. Also place 100 fruit flies at 29 degrees Celsius for one generation. If the hypothesis is correct, then the fruit flies that develop at 18 degrees Celsius will complete their life cycle after those fruit flies that are placed at 29 degrees Celsius."

Step 4: Analyze Results and State Conclusions

Reject the hypothesis if the results are not consistent with the hypothesis or accept the hypothesis as possibly true if the results are consistent with the hypothesis. Notice that the hypothesis is not “proven to be true” even if the results do support it. This is because there may be explanations other than the hypothesis for the experimental result. 

For example, if the fruit flies placed at 18 degrees Celsius do develop slower, it may be that their food is not as soft making it more difficult for the fruit flies to eat at the lower temperature, causing them to eat less food and thus grow slower.

Screen Shot 2019-06-16 at 5.53.55 PM.png

Figure \(\PageIndex{1}\). (CC BY-NC-SA)

Designing a Good Experiment

The most challenging part of the scientific method is usually the third step, designing and carrying out an experiment to test the hypothesis. A well-designed experiment should include all of the following characteristics:

1. An independent variable . The independent variable is the part of the experiment that the scientist changes or manipulates to see what effect occurs. “The temperature is the independent variable, since that is what the experiment changes to see its effect.”

2. A dependent variable . The dependent variable is the part of the experiment that changes because of the change in the independent variable. In other words, the dependent variable is the effect that occurs from changing the independent variable.

“The length of the fruit flies' life cycle is the dependent variable, since the time of development is expected to change because of the temperature.”

3. An experimental group . The experimental group is the group of subjects where the independent variable is set to an unusual or test level.

“The fruit flies placed at 18 degrees Celsius are the experimental group, since the effect of lower temperature on the life cycle of fruit flies is what is being tested.”

4. A control group . A control group is the group of subjects in the experiment that the experimental group is compared to. For the control group, the independent variable is set to a normal or usual level (which may be zero, if that is considered a normal level).

“The fruit flies kept at 29 degrees are the control group, since this is the optimal temperature for fruit fly development.”

Some experiments include things called positive controls and negative controls. These are slightly different than control groups. Positive and negative controls serve to show that the experiment is working correctly. A  positive control  is a part of the experiment that is deliberately designed to give a positive result. It shows that the experiment is capable of producing a positive result when it is supposed to. A  negative control  is a part of the experiment that is designed to give a negative result. It shows that the experiment is capable of producing a negative result when it is supposed to.

5. The experiment should contain repetition . This means that there should be more than one subject in the experimental group and the control group. Why? In general, the more repetition, the less likely that your results are due to random chance.

“The experimental group and the control group each contained 100 fruit flies.”

6. The experiment should be well defined . One aspect of “well defined” is that the procedure (the steps) must be written down and clearly described. The true test of a well written experimental procedure is that another scientist could duplicate it exactly using just the written directions. Another aspect of “well defined” is that everything in the experiment, such as the materials, chemicals, equipment, environmental conditions, and the subjects (the organisms involved in the experiment), should be described as exactly as possible. All of the factors that are kept equal in the experiment and control groups are called  standardized variables . Another aspect of “well defined” is that all parts of the experiment should be quantified. This means they should be measured by numbers. 

a) All fruit flies in this experiment are the same species (Drosophila melanogaster). All fruit flies were placed in plastic vials with standard cornmeal media and a cotton stopper. All fruit flies received artificial sunlight for 16 hours per day. 

b) One group of 100 fruit flies (the experimental group) were placed in an incubator set to 18 degrees Celsius.

c) One group of 100 fruit flies (the control group) were placed in an incubator set to 29 degrees Celsius.

d) In order to accurately determine the length of the life cycle of the fruit flies, 100 adult flies were allowed to lay eggs for 2 days and then removed from vials. Vials were monitored daily to determine the stage of the life cycle of the offspring of the original adult fruit flies. The end of the life cycle was recorded as the time when half of the fruit flies had undergone eclosion (adults emerge from the pupa case).

What is a Scientific Theory?

" It's just a theory ." Our everyday use of the term  theory  often implies a mere guess or something that is unproven. However, a scientific theory implies that something has been proven and is generally accepted as being true. A  scientific theory  is an explanation for natural events that is based on a large number of observations and has been verified multiple times. Theories help scientists to explain large amounts of data. 

A theory differs from a hypothesis in that it is much broader in scope and supported by a much greater body of evidence. Remember, a hypothesis is an educated guess that is based upon observation, but has not yet been proven.

While theories are not easily discarded, as they are based on a large body evidence, sometimes scientists must modify or even reject scientific theories when new research methods produce results that do not fit with the current theory. 

This tutorial was funded by the Title V-STEM Grant #P031S090007.

Resources you can trust

Identifying variables in biology required practicals

Identifying variables in biology required practicals

This GCSE biology worksheet gives students practice in identifying variables in the context of two biology practicals: a) the effect of pH on the rate of reaction of the enzyme amylase and b) the effect of light intensity on the rate of photosynthesis.

In the first task, students match the type of variable (independent variable, dependent variable and control variable) to the correct definition.

In the second and third tasks, students identify the variables in two descriptions of biology practicals: a) in the style of question that they might encounter in their GCSE exam and b) in the description of the experiment that a teacher might give in class

Answers are provided on the PowerPoint slides and in the Word document.

An extract from the answers:

All reviews

Resources you might like.

  • Other Resources
  • CK-12 Resources
  • Concept Map
  • Testimonials
  • CK-12 Mission
  • Meet the Team

Save Time. Teach more!

The CK-12 Foundation is a leading non-profit organization dedicated to increasing access to high-quality K-12 STEM Open Educational Resources (OER). Learn more

100% FREE BIOLOGY WORKSHEETS....

Practice worksheets covering Cell Biology, Human Biology, Molecular Biology, and more!

VIEW OUR FREE DIGITAL TEXTBOOKS

  • Biology Worksheets
  • Biology Textbooks

biology variables worksheet

Carbohydrates

The life of a eukaryotic cell can be divided into 4 distinct phases, ending with cell division.

Cell Cycle

Cell Division

Cell Cycle, Mitosis, and Meiosis: All cells reproduce by dividing into two genetically identical daughter cells.

Cellular Respiration

Cellular Respiration

Photosynthesis and Cellular Respiration: The cellular process which transfers chemical energy from glucose to ATP.

biology variables worksheet

Characteristics of Life

What characteristics do all living organisms share? We look at the characteristics of life including respiration, growth, and responding to their environment.

Radioactive Half-life

Chemistry of Life

The rate at which radioisotopes break down into smaller atomic nuclei.

Common Parts of the Cell

Common Parts of the Cell

Cellular Structure and Function How a cell functions is directly related to its structure. A nerve cell differs from a skin cell in how it looks and what is does.

Diffusion

Introduces diffusion and osmosis and how the concepts relate to cells.

DNA Structure and Replication

DNA Structure and Replication

Describes the DNA double helix and how DNA is copied.

DNA, the Genetic Material

DNA, the Genetic Material

Discuss identification of the genetic material.

Gregor Mendel and Genetics

Gregor Mendel and Genetics

Genetics is the study of heredity in organisms and was pioneered by Gregor Mendel's experiments.

Phospholipid Bilayers

Phospholipid Bilayers

A membrane where phospholipid molecules orient to provide qualities necessary to maintain a cell in a water-based environment.

Proteins

Made of smaller units called amino acids, proteins provide energy for cells and perform many cellular functions.

biology variables worksheet

Prokaryotic and Eukaryotic Cells

Prokaryotic cells lack a membrane bound nucleus. Eukaryotic cells have membrane bound organelles.

Scientific Methods

Scientific Methods

Scientific experiments involve observation, experimentation, and analysis of results.

Significance of Carbon

Significance of Carbon

Carbon is an element that has unique properties (exceptional ability to form bonds) that makes it essential to life on earth.

Meiosis

Cell Cycle, Mitosis, and Meiosis A type of cell division that produces haploid cells from a diploid parent cell.

Mitosis and Cytokinesis

Mitosis and Cytokinesis

Cell Cycle, Mitosis, and Meiosis The process by which eukaryotic cells divide to produce identical daughter cells.

Nucleic Acids

Nucleic Acids

Organic compounds that consist of carbon, hydrogen, oxygen, nitrogen, and phosphorus. Examples: DNA, RNA.

Lipids

Organic compounds composed of carbon, hydrogen and oxygen that do not mix with water.

CK-12 Biology

CK-12 Biology

CK-12 Biology is a high school FlexBook® textbook covering cell biology, genetics, evolution, ecology, microorganisms, fungi, plants, invertebrates, vertebrates...

CK-12 Biology Advanced Concepts

CK-12 Biology Advanced Concepts

Biology concepts for high school.

CK-12 Biology Concepts

CK-12 Biology Concepts

biology variables worksheet

CBSE Biology Book Class 9

This biology text was created using CK-12 resources to be seed content for a complete Biology Class 9 course for CBSE students.

CCBSE Biology Book Class 11

CBSE Biology Book Class 11

This biology text was created using CK-12 resources to be seed content for a complete Biology Class 11 course for CBSE students.

biology variables worksheet

CBSE Biology Book Class 12

This biology text was created using CK-12 resources to be seed content for a complete Biology Class 12 course for CBSE students.

CK-12 Fourth Grade Science

CK-12 Fourth Grade Science

Human Biology - Breathing

Human Biology - Breathing

The Breathing Student Edition book is one of ten volumes making up the Human Biology curriculum, an interdisciplinary and inquiry-based approach to the study of life science.

biology variables worksheet

Human Biology - Circulation

The Circulation Student Edition book is one of ten volumes making up the Human Biology curriculum, an interdisciplinary and inquiry-based approach to the study of life science.

Human Biology - Digestion and Nutrition

Human Biology - Digestion and Nutrition

The Digestion and Nutrition Student Edition book is one of ten volumes making up the Human Biology curriculum, an interdisciplinary and inquiry-based approach to the study of life science.

Human Biology - Ecology

Human Biology - Ecology

The Ecology Student Edition book is one of ten volumes making up the Human Biology curriculum, an interdisciplinary and inquiry-based approach to the study of life science.

Human Biology - Genetics

Human Biology - Genetics

The Genetics Student Edition book is one of ten volumes making up the Human Biology curriculum, an interdisciplinary and inquiry-based approach to the study of life science.

Human Biology - Nervous System

Human Biology - Nervous System

The Nervous System Student Edition book is one of ten volumes making up the Human Biology curriculum, an interdisciplinary and inquiry-based approach to the study of life science.

biology variables worksheet

Human Biology - Reproduction

The Reproduction Student Edition book is one of ten volumes making up the Human Biology curriculum, an interdisciplinary and inquiry-based approach to the study of life science.

biology variables worksheet

Human Biology - Sexuality

The Sexuality Student Edition book is one of ten volumes making up the Human Biology curriculum, an interdisciplinary and inquiry-based approach to the study of life science.

Human Biology - Lives of Cells

Human Biology - Lives of Cells

The Lives of Cells Student Edition book is one of ten volumes making up the Human Biology curriculum, an interdisciplinary and inquiry-based approach to the study of life science.

biology variables worksheet

Human Biology - Your Changing Body

The Your Changing Body Student Edition book is one of ten volumes making up the Human Biology curriculum, an interdisciplinary and inquiry-based approach to the study of life science.

CK-12 Life Science Concepts For Middle School

CK-12 Life Science Concepts For Middle School

Life Science concepts for middle school.

CK-12 Life Science For Middle School

CK-12 Life Science For Middle School

CK-12 Life Science For Middle School covers: Cell Biology, Genetics, Evolution, Prokaryotes, Protists, Fungi, Plants, The Animal Kingdom, The Human Body, and Ecology.

Spanish FlexBooks®

Conceptos Biología

CK-12 Conceptos Biología

Ck-12 overview.

  • International
  • Schools directory
  • Resources Jobs Schools directory News Search

How Science Works (HSW): Variables - Worksheet  (KS3/4)

How Science Works (HSW): Variables - Worksheet (KS3/4)

Subject: Biology

Age range: 11-14

Resource type: Worksheet/Activity

Game to Learn

Last updated

24 July 2022

  • Share through email
  • Share through twitter
  • Share through linkedin
  • Share through facebook
  • Share through pinterest

biology variables worksheet

Worksheet on variables which students can work through independently, 3 pages (pdf) with examples and extensions

Check out my other HSW resources here: https://www.tes.com/teaching-resource/resource-11763955

Creative Commons "NoDerivatives"

Get this resource as part of a bundle and save up to 63%

A bundle is a package of resources grouped together to teach a particular topic, or a series of lessons, in one place.

How Science Works (HSW) - 9x Games, activities and worksheets

Bundle with 9x HSW resources on scientific method, variables, and quality of results (reliable, accurate, valid), experimental design (CORMS) Great as starter, plenary or revision activities for printing: - Worksheet 1 (Variables) - Worksheet 2 (Fair test, reliable, accurate) - Worksheet 3 (Experimental design, CORMS) - HSW - Crossword - HSW - Loop game - HSW - Card sort / memory game - HSW - Tarsia game - Experimental design (CORMS) - Loop Game - Experimental design (CORMS) - Card Sort

Your rating is required to reflect your happiness.

It's good to leave some feedback.

Something went wrong, please try again later.

Very well done!

Empty reply does not make any sense for the end user

VictoriaOdong

Amazing, so well designed, thank you

excellent resource, thank you, it would also be great in a word file so I could edit it for differentiation

Simple but effective

Incredibly useful

Report this resource to let us know if it violates our terms and conditions. Our customer service team will review your report and will be in touch.

Not quite what you were looking for? Search by keyword to find the right resource:

IMAGES

  1. Identifying Variables Worksheet Answers

    biology variables worksheet

  2. ️Identifying Variables Worksheet Pdf Free Download| Goodimg.co

    biology variables worksheet

  3. Science Variables Plant Worksheet (Independent Variable & Dependent

    biology variables worksheet

  4. Identify Controls and Variables Key (NEW) by Biologycorner

    biology variables worksheet

  5. 30 Independent Variable And Dependent Variable Worksheet

    biology variables worksheet

  6. Biology

    biology variables worksheet

VIDEO

  1. What Are Variables?

  2. biology quiz worksheet part-2 #education #studies#learning#learn#youtubeviedos #viral#video#trending

  3. GCSE Biology Paper 1

  4. Biostatistics: Variable & Data (all you need to know)

  5. 🔴Applications of Biology 𝙥𝙖𝙧𝙩 ❶ G12 New Curriculum Biology Q/A #exam #grade12 #biology #science

  6. Linear Equations in Two Variables

COMMENTS

  1. Independent & Dependent Variables Practice

    Students identify variables as well as draw conclusions from observations. For differentiation, I also have a simpler version (low level) of the worksheet that gives multiple choice options. This version may also be useful for test preparation with other groups. Grade Level: 8-10. Time Required: 15-20 minutes.

  2. PDF VARIABLES WORKSHEET #2: MORE PRACTICE

    For each experiment below, specify the independent variable, dependent variable, control group and any constants. A student wanted to test how the mass of a paper airplane affected the distance it would fly. Paper clips were added before each test flight. As each paper clip was added, the plane was tested to determine how far it would fly.

  3. Independent and Dependent Variables Scenarios

    Scenarios. For each, identify the independent (manipulated) and dependent (responding) variable. 1. A cow is given a growth hormone and then compared to another cow that was not given a growth hormone. Both cows were weighed at 2 years. 2. Mosquito repellent is sprayed on one arm and the other arm is not sprayed.

  4. PDF Identifying Variables

    Identifying Variables ANSWER KEY. Name: Period: Date: Directions: Read through each scenario and identify the independent variable, dependent variable, and the control. Beware- not all experiments will have a control! Sara wants to see if a new brand of hair dye lasts longer than the brand she currently uses.

  5. PDF Identifying Variables and Writing a Hypothesis

    underline the independent variable, circle the dependent variable, and list 3 constant/control variables. Then, write a hypothesis or prediction. 1. How does the distance from an eye chart affect the number of letters that are recognized on a line? Constant/Control Variables: eye chart, position of viewer, light in room

  6. Biology Worksheets, Notes, and Quizzes (PDF and PNG)

    Get free biology notes, worksheets, quizzes, and slides that you can download and print. This is a collection of free biology worksheets, notes, handouts, slides, study guides and quizzes. Most content targets high school, AP biology, genetics, anatomy/physiology, immunology, and biology 101 and 102 in college.

  7. Scientific Method

    In other words, the dependent variable is the effect that occurs from changing the independent variable. "The length of the fruit flies' life cycle is the dependent variable, since the time of development is expected to change because of the temperature." 3. An experimental group. The experimental group is the group of subjects where the ...

  8. Identifying variables

    This GCSE biology worksheet gives students practice in identifying variables in the context of two biology practicals: a) the effect of pH on the rate of reaction of the enzyme amylase and b) the effect of light intensity on the rate of photosynthesis. In the first task, students match the type of variable (independent variable, dependent ...

  9. Biology Independent And Independent Variables Worksheets ...

    This worksheet is the first step in the process of teaching them how to design their own experiment. This worksheet focuses on explicitly teaching students about independent variable. Subjects: Science, Biology, Chemistry. Grades: 6th - 8th. Types: Worksheets, Handouts, Minilessons. CCSS:

  10. FREE Identifying Variables Practice by Science Teacher Resources

    This worksheet is a designed as practice identifying variables, although it may be used as an introduction or homework. Objective: Students will be able to identify independent, dependent, and control variables. Common Core Standard (s) Alignment: CCSS.ELA-Literacy.RST.6-8.4 Determine the meaning of symbols, key terms, and other domain-specific ...

  11. PDF Identify the Independent and Dependent Variables in ...

    James wants to know the effect of studying an extra 10 minutes each day on his Biology grade. IV:_____time studying_____ DV:_____grade_____ 4. Joelle wants to determine the effect of pesticides on the size of the apples in the orchard. ... Identify the Independent and Dependent Variables in each of the scenarios Author: Brad Created Date:

  12. Worksheets

    This biology text was created using CK-12 resources to be seed content for a complete Biology Class 12 course for CBSE students. The Breathing Student Edition book is one of ten volumes making up the Human Biology curriculum, an interdisciplinary and inquiry-based approach to the study of life science.

  13. Variables

    1. Plant growth and water. Adding different amounts of water to a plant could affect its growth. To investigate this, plant some seeds and water each plant with different amount over time. The ...

  14. PDF Variables & Hypothesis Worksheet

    Independent Variable (What will you be changing in the . experiment. Note: There should . only be one item listed here) Dependent Variables (What will you be measuring or . observing) Controlled Variables (What will you be keeping the same . during the experiment) Your Hypothesis (Fill in the blanks with the appropriate information from your ...

  15. Experimental Variable Worksheet Flashcards

    Terms in this set (12) An independent variable is. What the experimenter changes during the experiment. A dependent variable is. What the experimenter measures. Constants are. things that are kept the same. The control is. the thing to compare against to see if independent variable has any affect.

  16. Variables

    General Biology Start typing, then use the up and down arrows to select an option from the list.? Get exam ready ... Worksheet. Introduction to Biology. 8m. Characteristics of Life. 12m. ... Dependent And Controlled Variables? HighSchoolScience101. 322. views. 00:32. Animation: Atomic Number and Atomic Mass. Pearson. 937.

  17. How Science Works (HSW): Variables

    How Science Works (HSW): Variables - Worksheet (KS3/4) Subject: Biology. Age range: 11-14. Resource type: Worksheet/Activity. File previews. pdf, 1.04 MB. Worksheet on variables which students can work through independently, 3 pages (pdf) with examples and extensions. Check out my other HSW resources here:

  18. Identify Controls and Variables Key (NEW) by Biologycorner

    Description. Student worksheet is available for free download from biologycorner.com. Students identify the controls and variables (manipulated and responding) and write conclusions for short experiments performed by Simpsons characters. This resource was updated 9/10/2022 and includes a new set of scenarios in Word format.