- Home
- Find Gizmos
- Browse by Core Curriculum
- Holt Textbooks
- Biology (2004)
Biology (2004)
Unit 1. Principles of Cell Biology
Chapter 1. Biology and You
Cell Structure
Select a sample cell from an animal, plant, or bacterium and view the cell under a microscope. Select each organelle on the image to learn more about its structure and function. Closeup views and animations of certain organelles is provided. 5 Minute Preview
Mouse Genetics (Two Traits)
Breed "pure" mice with known genotypes that exhibit specific fur and eye colors, and learn how traits are passed on via dominant and recessive genes. Mice can be stored in cages for future breeding, and the statistics of fur and eye color are reported every time a pair of mice breed. Punnett squares can be used to predict results. 5 Minute Preview
Chicken Genetics
Breed "pure" chickens with known genotypes that exhibit specific feather colors, and learn how traits are passed on via codominant genes. Chickens can be stored in cages for future breeding, and the statistics of feather color are reported every time the chickens breed. Punnett squares can be used to predict results. 5 Minute Preview
Food Chain
In this ecosystem consisting of hawks, snakes, rabbits and grass, the population of each species can be studied as part of a food chain. Disease can be introduced for any species, and the number of animals can be increased or decreased at any time, just like in the real world. 5 Minute Preview
Human Karyotyping
Sort and pair the images of human chromosomes obtained in a scan. Find differences in the scans of the various patients to find out specific things that can cause disease, as well as determining the sex of the person. 5 Minute Preview
Disease Spread
Observe the spread of disease through a group of people. The methods of transmission can be chosen and include person-to-person, airborne, and foodborne as well as any combination thereof. The probability of each form of transmission and number of people in the group can also be adjusted. 5 Minute Preview
Rabbit Population by Season
Observe the population of rabbits in an environment over many years. The land available to the rabbits and weather conditions can be adjusted to investigate the effects of urban sprawl and unusual weather on wildlife populations. 5 Minute Preview
pH Analysis
Test the acidity of common substances using pH paper. Materials including soap, lemon juice, milk, and oven cleaner can be tested by comparing the color of pH strips to a standard scale. 5 Minute Preview
Seed Germination
Perform experiments with several seed types to see what conditions yield the highest germination (sprouting) rate. Three different types of seeds can be studied, and the temperature, water and light in the germination chamber can be controlled. No two trials will have the same result so repeated trials are recommended. 5 Minute Preview
Chapter 2. Chemistry of Life
Element Builder
Use protons, neutrons, and electrons to build elements. As the number of protons, neutrons, and electrons changes, information such as the name and symbol of the element, the Z, N, and A numbers, the electron dot diagram, and the group and period from the periodic table are shown. Each element is classified as a metal, metalloid, or nonmetal, and its state at room temperature is also given. 5 Minute Preview
pH Analysis
Test the acidity of common substances using pH paper. Materials including soap, lemon juice, milk, and oven cleaner can be tested by comparing the color of pH strips to a standard scale. 5 Minute Preview
Identifying Nutrients
Use a variety of real-world lab tests to analyze common food samples in order to determine if the food is a carbohydrate, a protein, or a lipid. Tests that can be performed include: Benedict, Lugol, Biuret, and Sudan Red. 5 Minute Preview
Building DNA
Construct a DNA molecule, examine its double-helix structure, and then go through the DNA replication process. Learn how each component fits into a DNA molecule, and see how a unique, self-replicating code can be created. 5 Minute Preview
RNA and Protein Synthesis
Go through the process of synthesizing proteins through RNA transcription and translation. Learn about the many steps involved in protein synthesis including: unzipping of DNA, formation of mRNA, attaching of mRNA to the ribosome, and linking of amino acids to form a protein. 5 Minute Preview
Chapter 3. Cell Structure
Cell Structure
Select a sample cell from an animal, plant, or bacterium and view the cell under a microscope. Select each organelle on the image to learn more about its structure and function. Closeup views and animations of certain organelles is provided. 5 Minute Preview
Cell Structure
Select a sample cell from an animal, plant, or bacterium and view the cell under a microscope. Select each organelle on the image to learn more about its structure and function. Closeup views and animations of certain organelles is provided. 5 Minute Preview
Cell Energy Cycle
Explore the processes of photosynthesis and respiration that occur within plant and animal cells. The cyclical nature of the two processes can be constructed visually, and the simplified photosynthesis and respiration formulae can be balanced. 5 Minute Preview
Chapter 4. Cells and Their Environment
Diffusion
Explore the motion of particles as they bounce around from one side of a room to the other through an adjustable gap or partition. The mass of the particles can be adjusted, as well as the temperature of the room and the initial number of particles. In a real-world context, this can be used to learn about how odors travel, fluids move through gaps, the thermodynamics of gases, and statistical probability. 5 Minute Preview
Osmosis
Adjust the concentration of a solute on either side of a membrane in a cell and observe the system as it adjusts to the conditions through osmosis. The initial concentration of the solute can be manipulated, along with the volume of the cell. 5 Minute Preview
Chapter 5. Photosynthesis and Cellular Respiration
Photosynthesis Lab
Study photosynthesis in a variety of conditions. Oxygen production is used to measure the rate of photosynthesis. Light intensity, carbon dioxide levels, temperature, and wavelength of light can all be varied. Determine which conditions are ideal for photosynthesis, and understand how limiting factors affect oxygen production. 5 Minute Preview
Photosynthesis Lab
Study photosynthesis in a variety of conditions. Oxygen production is used to measure the rate of photosynthesis. Light intensity, carbon dioxide levels, temperature, and wavelength of light can all be varied. Determine which conditions are ideal for photosynthesis, and understand how limiting factors affect oxygen production. 5 Minute Preview
Cell Energy Cycle
Explore the processes of photosynthesis and respiration that occur within plant and animal cells. The cyclical nature of the two processes can be constructed visually, and the simplified photosynthesis and respiration formulae can be balanced. 5 Minute Preview
Basic Prism
Shine white light or a single-color beam through a prism. Explore how a prism refracts light and investigate the factors that affect the amount of refraction. The index of refraction of the prism, width of the prism, prism angle, light angle, and light wavelength can be adjusted. 5 Minute Preview
Cell Energy Cycle
Explore the processes of photosynthesis and respiration that occur within plant and animal cells. The cyclical nature of the two processes can be constructed visually, and the simplified photosynthesis and respiration formulae can be balanced. 5 Minute Preview
Chapter 6. Chromosomes and Cell Reproduction
Cell Division
Begin with a single cell and watch as mitosis and cell division occurs. The cells will go through the steps of interphase, prophase, metaphase, anaphase, telophase, and cytokinesis. The length of the cell cycle can be controlled, and data related to the number of cells present and their current phase can be recorded. 5 Minute Preview
Human Karyotyping
Sort and pair the images of human chromosomes obtained in a scan. Find differences in the scans of the various patients to find out specific things that can cause disease, as well as determining the sex of the person. 5 Minute Preview
Cell Division
Begin with a single cell and watch as mitosis and cell division occurs. The cells will go through the steps of interphase, prophase, metaphase, anaphase, telophase, and cytokinesis. The length of the cell cycle can be controlled, and data related to the number of cells present and their current phase can be recorded. 5 Minute Preview
Cell Division
Begin with a single cell and watch as mitosis and cell division occurs. The cells will go through the steps of interphase, prophase, metaphase, anaphase, telophase, and cytokinesis. The length of the cell cycle can be controlled, and data related to the number of cells present and their current phase can be recorded. 5 Minute Preview
Unit 2. Principles of Genetics
Chapter 7. Meiosis and Sexual Reproduction
Cell Division
Begin with a single cell and watch as mitosis and cell division occurs. The cells will go through the steps of interphase, prophase, metaphase, anaphase, telophase, and cytokinesis. The length of the cell cycle can be controlled, and data related to the number of cells present and their current phase can be recorded. 5 Minute Preview
Human Karyotyping
Sort and pair the images of human chromosomes obtained in a scan. Find differences in the scans of the various patients to find out specific things that can cause disease, as well as determining the sex of the person. 5 Minute Preview
Chapter 8. Mendel and Heredity
Mouse Genetics (One Trait)
Breed "pure" mice with known genotypes that exhibit specific fur colors, and learn how traits are passed on via dominant and recessive genes. Mice can be stored in cages for future breeding, and the statistics of fur color are reported every time a pair of mice breed. Punnett squares can be used to predict results. 5 Minute Preview
Mouse Genetics (One Trait)
Breed "pure" mice with known genotypes that exhibit specific fur colors, and learn how traits are passed on via dominant and recessive genes. Mice can be stored in cages for future breeding, and the statistics of fur color are reported every time a pair of mice breed. Punnett squares can be used to predict results. 5 Minute Preview
Mouse Genetics (Two Traits)
Breed "pure" mice with known genotypes that exhibit specific fur and eye colors, and learn how traits are passed on via dominant and recessive genes. Mice can be stored in cages for future breeding, and the statistics of fur and eye color are reported every time a pair of mice breed. Punnett squares can be used to predict results. 5 Minute Preview
Chicken Genetics
Breed "pure" chickens with known genotypes that exhibit specific feather colors, and learn how traits are passed on via codominant genes. Chickens can be stored in cages for future breeding, and the statistics of feather color are reported every time the chickens breed. Punnett squares can be used to predict results. 5 Minute Preview
Human Karyotyping
Sort and pair the images of human chromosomes obtained in a scan. Find differences in the scans of the various patients to find out specific things that can cause disease, as well as determining the sex of the person. 5 Minute Preview
Chapter 9. DNA: The Genetic Material
Virus Lytic Cycle
Release a lytic virus in a group of cells and observe how cells are infected over time and eventually destroyed. Data related to the number of healthy cells, infected cells, and viruses can be recorded over time to determine the time required for the virus to mature within a cell. 5 Minute Preview
Building DNA
Construct a DNA molecule, examine its double-helix structure, and then go through the DNA replication process. Learn how each component fits into a DNA molecule, and see how a unique, self-replicating code can be created. 5 Minute Preview
Building DNA
Construct a DNA molecule, examine its double-helix structure, and then go through the DNA replication process. Learn how each component fits into a DNA molecule, and see how a unique, self-replicating code can be created. 5 Minute Preview
Building DNA
Construct a DNA molecule, examine its double-helix structure, and then go through the DNA replication process. Learn how each component fits into a DNA molecule, and see how a unique, self-replicating code can be created. 5 Minute Preview
Chapter 10. How Proteins Are Made
RNA and Protein Synthesis
Go through the process of synthesizing proteins through RNA transcription and translation. Learn about the many steps involved in protein synthesis including: unzipping of DNA, formation of mRNA, attaching of mRNA to the ribosome, and linking of amino acids to form a protein. 5 Minute Preview
RNA and Protein Synthesis
Go through the process of synthesizing proteins through RNA transcription and translation. Learn about the many steps involved in protein synthesis including: unzipping of DNA, formation of mRNA, attaching of mRNA to the ribosome, and linking of amino acids to form a protein. 5 Minute Preview
Chapter 11. Gene Technology
DNA Analysis
Scan the DNA of frogs to produce DNA sequences. Use the DNA sequences to identify possible identical twins and to determine which sections of DNA code for skin color, eye color, and the presence or absence of spots. 5 Minute Preview
Unit 3. Principles of Evolution
Chapter 12. History of Life on Earth
Half-life
Investigate the decay of a radioactive substance. The half-life and the number of radioactive atoms can be adjusted, and theoretical or random decay can be observed. Data can be interpreted visually using a dynamic graph, a bar chart, and a table. Determine the half-lives of two sample isotopes as well as samples with randomly generated half-lives. 5 Minute Preview
Chapter 13. The Theory of Evolution
Rainfall and Bird Beaks
Study the thickness of birds' beaks over a five-year period as you control the yearly rainfall on an isolated island. As the environmental conditions change, the species must adapt (a real-world consequence) to avoid extinction. 5 Minute Preview
Rainfall and Bird Beaks
Study the thickness of birds' beaks over a five-year period as you control the yearly rainfall on an isolated island. As the environmental conditions change, the species must adapt (a real-world consequence) to avoid extinction. 5 Minute Preview
Natural Selection
You are a bird hunting moths (both dark and light) that live on trees. As you capture the moths most easily visible against the tree surface, the moth populations change, illustrating the effects of natural selection. 5 Minute Preview
Rainfall and Bird Beaks
Study the thickness of birds' beaks over a five-year period as you control the yearly rainfall on an isolated island. As the environmental conditions change, the species must adapt (a real-world consequence) to avoid extinction. 5 Minute Preview
Chapter 14. Classification of Organisms
Unit 4. Principles of Ecology
Chapter 15. Populations
Rabbit Population by Season
Observe the population of rabbits in an environment over many years. The land available to the rabbits and weather conditions can be adjusted to investigate the effects of urban sprawl and unusual weather on wildlife populations. 5 Minute Preview
Estimating Population Size
Adjust the number of fish in a lake to be tagged and the number of fish to be recaptured. Use the number of tagged fish in the catch to estimate the number of fish in the lake. 5 Minute Preview
Food Chain
In this ecosystem consisting of hawks, snakes, rabbits and grass, the population of each species can be studied as part of a food chain. Disease can be introduced for any species, and the number of animals can be increased or decreased at any time, just like in the real world. 5 Minute Preview
Natural Selection
You are a bird hunting moths (both dark and light) that live on trees. As you capture the moths most easily visible against the tree surface, the moth populations change, illustrating the effects of natural selection. 5 Minute Preview
Rainfall and Bird Beaks
Study the thickness of birds' beaks over a five-year period as you control the yearly rainfall on an isolated island. As the environmental conditions change, the species must adapt (a real-world consequence) to avoid extinction. 5 Minute Preview
Rabbit Population by Season
Observe the population of rabbits in an environment over many years. The land available to the rabbits and weather conditions can be adjusted to investigate the effects of urban sprawl and unusual weather on wildlife populations. 5 Minute Preview
Food Chain
In this ecosystem consisting of hawks, snakes, rabbits and grass, the population of each species can be studied as part of a food chain. Disease can be introduced for any species, and the number of animals can be increased or decreased at any time, just like in the real world. 5 Minute Preview
Chapter 16. Ecosystems
Water Cycle
Control the path of a drop of water as it travels through the water cycle. Many alternatives are presented at each stage. Determine how the water moves from one location to another, and learn how water resources are distributed in these locations. 5 Minute Preview
Rock Cycle
Play the role of a piece of rock moving through the rock cycle. Select a starting location and follow many possible paths throughout the cycle. Learn how rocks are formed, weathered, eroded, and reformed as they move from Earth's surface to locations deep within the crust. 5 Minute Preview
Food Chain
In this ecosystem consisting of hawks, snakes, rabbits and grass, the population of each species can be studied as part of a food chain. Disease can be introduced for any species, and the number of animals can be increased or decreased at any time, just like in the real world. 5 Minute Preview
Water Cycle
Control the path of a drop of water as it travels through the water cycle. Many alternatives are presented at each stage. Determine how the water moves from one location to another, and learn how water resources are distributed in these locations. 5 Minute Preview
Chapter 17. Biological Communities
Food Chain
In this ecosystem consisting of hawks, snakes, rabbits and grass, the population of each species can be studied as part of a food chain. Disease can be introduced for any species, and the number of animals can be increased or decreased at any time, just like in the real world. 5 Minute Preview
Food Chain
In this ecosystem consisting of hawks, snakes, rabbits and grass, the population of each species can be studied as part of a food chain. Disease can be introduced for any species, and the number of animals can be increased or decreased at any time, just like in the real world. 5 Minute Preview
Chapter 18. The Environment
Greenhouse Effect
Within this simulated region of land, daytime's rising temperature and the falling temperature at night can be measured, along with heat flow in and out of the system. The level of greenhouse gases present in the atmosphere at any given time can be adjusted, allowing the long-term effects to be investigated. 5 Minute Preview
Temperature and Sex Determination
Observe the sex ratios of birds and geckos as they hatch in an incubator. Vary the temperature of the incubator and measure the percentages of male and female hatchlings to determine if temperature has an effect on sex. 5 Minute Preview
Natural Selection
You are a bird hunting moths (both dark and light) that live on trees. As you capture the moths most easily visible against the tree surface, the moth populations change, illustrating the effects of natural selection. 5 Minute Preview
Water Cycle
Control the path of a drop of water as it travels through the water cycle. Many alternatives are presented at each stage. Determine how the water moves from one location to another, and learn how water resources are distributed in these locations. 5 Minute Preview
Water Pollution
Get to know the four main types of pollution present in the environment, and then look at a variety of real-world examples as you try to guess what type of pollution is represented by each situation. All of the real-world situations can be viewed every day in different parts of the world. 5 Minute Preview
Unit 5. Exploring Diversity
Chapter 19. Introduction to the Kingdoms of Life
Chapter 20. Viruses and Bacteria
Virus Lytic Cycle
Release a lytic virus in a group of cells and observe how cells are infected over time and eventually destroyed. Data related to the number of healthy cells, infected cells, and viruses can be recorded over time to determine the time required for the virus to mature within a cell. 5 Minute Preview
Disease Spread
Observe the spread of disease through a group of people. The methods of transmission can be chosen and include person-to-person, airborne, and foodborne as well as any combination thereof. The probability of each form of transmission and number of people in the group can also be adjusted. 5 Minute Preview
Chapter 21. Protists
Chapter 22. Fungi
Unit 6. Exploring Plants
Chapter 23. Introduction to Plants
Cell Structure
Select a sample cell from an animal, plant, or bacterium and view the cell under a microscope. Select each organelle on the image to learn more about its structure and function. Closeup views and animations of certain organelles is provided. 5 Minute Preview
Pollination: Flower to Fruit
Label a diagram that illustrates the anatomy of a flower, and understand the function of each structure. Compare the processes of self pollination and cross pollination, and explore how fertilization takes place in a flowering plant. 5 Minute Preview
Pollination: Flower to Fruit
Label a diagram that illustrates the anatomy of a flower, and understand the function of each structure. Compare the processes of self pollination and cross pollination, and explore how fertilization takes place in a flowering plant. 5 Minute Preview
Chapter 24. Plant Reproduction
Pollination: Flower to Fruit
Label a diagram that illustrates the anatomy of a flower, and understand the function of each structure. Compare the processes of self pollination and cross pollination, and explore how fertilization takes place in a flowering plant. 5 Minute Preview
Pollination: Flower to Fruit
Label a diagram that illustrates the anatomy of a flower, and understand the function of each structure. Compare the processes of self pollination and cross pollination, and explore how fertilization takes place in a flowering plant. 5 Minute Preview
Chapter 25. Plant Structure and Function
Chapter 26. Plant Growth and Development
Seed Germination
Perform experiments with several seed types to see what conditions yield the highest germination (sprouting) rate. Three different types of seeds can be studied, and the temperature, water and light in the germination chamber can be controlled. No two trials will have the same result so repeated trials are recommended. 5 Minute Preview
Photosynthesis Lab
Study photosynthesis in a variety of conditions. Oxygen production is used to measure the rate of photosynthesis. Light intensity, carbon dioxide levels, temperature, and wavelength of light can all be varied. Determine which conditions are ideal for photosynthesis, and understand how limiting factors affect oxygen production. 5 Minute Preview
Photosynthesis Lab
Study photosynthesis in a variety of conditions. Oxygen production is used to measure the rate of photosynthesis. Light intensity, carbon dioxide levels, temperature, and wavelength of light can all be varied. Determine which conditions are ideal for photosynthesis, and understand how limiting factors affect oxygen production. 5 Minute Preview
Identifying Nutrients
Use a variety of real-world lab tests to analyze common food samples in order to determine if the food is a carbohydrate, a protein, or a lipid. Tests that can be performed include: Benedict, Lugol, Biuret, and Sudan Red. 5 Minute Preview
Unit 7. Exploring Invertebrates
Chapter 27. Introduction to Animals
Chapter 28. Simple Invertebrates
Chapter 29. Mollusks and Annelids
Chapter 30. Arthropods
Chapter 31. Echinoderms and Invertebrate Chordates
Unit 8. Exploring Vertebrates
Chapter 32. Vertebrates in the Sea and on Land
Chapter 33. Fishes and Amphibians
Chapter 34. Reptiles and Birds
Chapter 35. Mammals
Chapter 36. Animal Behavior
Unit 9. Exploring Human Biology
Chapter 37. Introduction to Body Structure
Chapter 38. Circulatory and Respiratory Systems
Chapter 39. Digestive and Excretory Systems
Identifying Nutrients
Use a variety of real-world lab tests to analyze common food samples in order to determine if the food is a carbohydrate, a protein, or a lipid. Tests that can be performed include: Benedict, Lugol, Biuret, and Sudan Red. 5 Minute Preview
pH Analysis
Test the acidity of common substances using pH paper. Materials including soap, lemon juice, milk, and oven cleaner can be tested by comparing the color of pH strips to a standard scale. 5 Minute Preview
Chapter 40. The Body's Defences
Disease Spread
Observe the spread of disease through a group of people. The methods of transmission can be chosen and include person-to-person, airborne, and foodborne as well as any combination thereof. The probability of each form of transmission and number of people in the group can also be adjusted. 5 Minute Preview
Chapter 41. Nervous System
Sight vs. Sound Reactions
Measure your reaction time by clicking your mouse as quickly as possible when visual or auditory stimuli are presented. The individual response times are recorded, as well as the mean and standard deviation for each test. A histogram of data shows overall trends in sight and sound response times. The type of test as well as the symbols and sounds used are chosen by the user. 5 Minute Preview
Sight vs. Sound Reactions
Measure your reaction time by clicking your mouse as quickly as possible when visual or auditory stimuli are presented. The individual response times are recorded, as well as the mean and standard deviation for each test. A histogram of data shows overall trends in sight and sound response times. The type of test as well as the symbols and sounds used are chosen by the user. 5 Minute Preview
Sight vs. Sound Reactions
Measure your reaction time by clicking your mouse as quickly as possible when visual or auditory stimuli are presented. The individual response times are recorded, as well as the mean and standard deviation for each test. A histogram of data shows overall trends in sight and sound response times. The type of test as well as the symbols and sounds used are chosen by the user. 5 Minute Preview
Sight vs. Sound Reactions
Measure your reaction time by clicking your mouse as quickly as possible when visual or auditory stimuli are presented. The individual response times are recorded, as well as the mean and standard deviation for each test. A histogram of data shows overall trends in sight and sound response times. The type of test as well as the symbols and sounds used are chosen by the user. 5 Minute Preview
Chapter 42. Hormones and the Endocrine System
Chapter 43. Reproduction and Development
How Free Gizmos Work
Start teaching with 20-40 Free Gizmos. See the full list.
Access lesson materials for Free Gizmos including teacher guides, lesson plans, and more.
All other Gizmos are limited to a 5 Minute Preview and can only be used for 5 minutes a day.
Free Gizmos change each semester. The new collection will be available January 1 and July 1.
About STEM Cases
Students assume the role of a scientist trying to solve a real world problem. They use scientific practices to collect and analyze data, and form and test a hypothesis as they solve the problems.
Each STEM Case uses realtime reporting to show live student results.
Introduction to the Heatmap
STEM Cases take between 30-90 minutes for students to complete, depending on the case.
Student progress is automatically saved so that STEM Cases can be completed over multiple sessions.
Multiple grade-appropriate versions, or levels, exist for each STEM Case.
Each STEM Case level has an associated Handbook. These are interactive guides that focus on the science concepts underlying the case.
Find Your Solution
Start playing, exploring and learning today with a free account. Or contact us for a quote or demo.
Sign Up For Free Get a Quote