Holt McDougal Biology (2012)

Growing Plants

Investigate the growth of three common garden plants: tomatoes, beans, and turnips. You can change the amount of light each plant gets, the amount of water added each day, and the type of soil the seed is planted in. Observe the effect of each variable on plant height, plant mass, leaf color and leaf size. Determine what conditions produce the tallest and healthiest plants. Height and mass data are displayed on tables and graphs. 5 Minute Preview

Collision Theory

Observe a chemical reaction with and without a catalyst. Determine the effects of concentration, temperature, surface area, and catalysts on reaction rates. Reactant and product concentrations through time are recorded, and the speed of the simulation can be adjusted by the user. 5 Minute Preview

Dehydration Synthesis

Build a glucose molecule, atom-by-atom, to learn about chemical bonds and the structure of glucose. Explore the processes of dehydration synthesis and hydrolysis in carbohydrate molecules. 5 Minute Preview

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

Ionic Bonds

Simulate ionic bonds between a variety of metals and nonmetals. Select a metal and a nonmetal atom, and transfer electrons from one to the other. Observe the effect of gaining and losing electrons on charge, and rearrange the atoms to represent the molecular structure. Additional metal and nonmetal atoms can be added to the screen, and the resulting chemical formula can be displayed. 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

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

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

Unit Conversions

Use unit conversion tiles to convert from one unit to another. Tiles can be flipped to cancel units. Convert between metric units or between metric and U.S. customary units. Solve distance, time, speed, mass, volume, and density problems. 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

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 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

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

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

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

Evolution: Mutation and Selection

Observe evolution in a fictional population of bugs. Set the background to any color, and see natural selection taking place. Inheritance of color occurs according to Mendel's laws and probability. Mutations occur at random, and probability of capture by predators is determined by the insect's camouflage. 5 Minute Preview

Hardy-Weinberg Equilibrium

Set the initial percentages of three types of parrots in a population and track changes in genotype and allele frequency through several generations. Analyze population data to develop an understanding of the Hardy-Weinberg equilibrium. Determine how initial allele percentages will affect the equilibrium state of the population. 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

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

Evolution: Mutation and Selection

Observe evolution in a fictional population of bugs. Set the background to any color, and see natural selection taking place. Inheritance of color occurs according to Mendel's laws and probability. Mutations occur at random, and probability of capture by predators is determined by the insect's camouflage. 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

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

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

Evolution: Mutation and Selection

Observe evolution in a fictional population of bugs. Set the background to any color, and see natural selection taking place. Inheritance of color occurs according to Mendel's laws and probability. Mutations occur at random, and probability of capture by predators is determined by the insect's camouflage. 5 Minute Preview

Inheritance

Create aliens with different traits and breed them to produce offspring. Determine which traits are passed down from parents to offspring and which traits are acquired. Offspring can be stored for future experiments or released. 5 Minute Preview

Microevolution

Observe the effect of predators on a population of parrots with three possible genotypes. The initial percentages and fitness levels of each genotype can be set. Determine how initial fitness levels affect genotype and allele frequencies through several generations. Compare scenarios in which a dominant allele is deleterious, a recessive allele is deleterious, and the heterozygous individual is fittest. 5 Minute Preview

Rainfall and Bird Beaks - Metric

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

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

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

Evolution: Mutation and Selection

Observe evolution in a fictional population of bugs. Set the background to any color, and see natural selection taking place. Inheritance of color occurs according to Mendel's laws and probability. Mutations occur at random, and probability of capture by predators is determined by the insect's camouflage. 5 Minute Preview

Evolution: Natural and Artificial Selection

Observe evolution in a fictional population of bugs. Set the background to any color, and see natural selection taking place. Compare the processes of natural and artificial selection. Manipulate the mutation rate, and determine how mutation rate affects adaptation and evolution. 5 Minute Preview

Hardy-Weinberg Equilibrium

Set the initial percentages of three types of parrots in a population and track changes in genotype and allele frequency through several generations. Analyze population data to develop an understanding of the Hardy-Weinberg equilibrium. Determine how initial allele percentages will affect the equilibrium state of the population. 5 Minute Preview

Microevolution

Observe the effect of predators on a population of parrots with three possible genotypes. The initial percentages and fitness levels of each genotype can be set. Determine how initial fitness levels affect genotype and allele frequencies through several generations. Compare scenarios in which a dominant allele is deleterious, a recessive allele is deleterious, and the heterozygous individual is fittest. 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

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

Human Evolution - Skull Analysis

Compare the skulls of a variety of significant human ancestors, or hominids. Use available tools to measure lengths, areas, and angles of important features. Each skull can be viewed from the front, side, or from below. Additional information regarding the age, location, and discoverer of each skull can be displayed. 5 Minute Preview

Coral Reefs 1 - Abiotic Factors

Explore the abiotic factors that affect Caribbean coral reefs. Many factors can be manipulated in this simplified reef model, including ocean temperature and pH, storm severity, and input of excess sediments and nutrients from logging, sewage, and agriculture. Click "Advance year" to see how the reef responds to these changes. 5 Minute Preview

Coral Reefs 2 - Biotic Factors

In this followup to the Coral Reefs 1 - Abiotic Factors activity, investigate the impacts of fishing, disease, and invasive species on a model Caribbean coral reef. Many variables can be manipulated, included intensity of fishing, presence of black band and white band disease, and the presence of actual and potential invasive species. Click "Advance year" to see the impacts of these biotic changes. 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

Forest Ecosystem

Observe and manipulate the populations of four creatures (trees, deer, bears, and mushrooms) in a forest. Investigate the feeding relationships (food web) in the forest. Determine which creatures are producers, consumers, and decomposers. Pictographs and line graphs show changes in populations over time. 5 Minute Preview

Pond Ecosystem

Measure the temperature and oxygen content of a pond over the course of a day. Then go fishing to see what types of fish live in the pond. Many different ponds can be investigated to determine the influence of time, temperature, and farms on oxygen levels. 5 Minute Preview

Prairie Ecosystem

Observe the populations of grass, prairie dogs, ferrets and foxes in a prairie ecosystem. Investigate feeding relationships and determine the food chain. Bar graphs and line graphs show changes in populations over time. 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

Forest Ecosystem

Observe and manipulate the populations of four creatures (trees, deer, bears, and mushrooms) in a forest. Investigate the feeding relationships (food web) in the forest. Determine which creatures are producers, consumers, and decomposers. Pictographs and line graphs show changes in populations over time. 5 Minute Preview

Prairie Ecosystem

Observe the populations of grass, prairie dogs, ferrets and foxes in a prairie ecosystem. Investigate feeding relationships and determine the food chain. Bar graphs and line graphs show changes in populations over time. 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

Coral Reefs 1 - Abiotic Factors

Explore the abiotic factors that affect Caribbean coral reefs. Many factors can be manipulated in this simplified reef model, including ocean temperature and pH, storm severity, and input of excess sediments and nutrients from logging, sewage, and agriculture. Click "Advance year" to see how the reef responds to these changes. 5 Minute Preview

Coral Reefs 2 - Biotic Factors

In this followup to the Coral Reefs 1 - Abiotic Factors activity, investigate the impacts of fishing, disease, and invasive species on a model Caribbean coral reef. Many variables can be manipulated, included intensity of fishing, presence of black band and white band disease, and the presence of actual and potential invasive species. Click "Advance year" to see the impacts of these biotic changes. 5 Minute Preview

Coral Reefs 1 - Abiotic Factors

Explore the abiotic factors that affect Caribbean coral reefs. Many factors can be manipulated in this simplified reef model, including ocean temperature and pH, storm severity, and input of excess sediments and nutrients from logging, sewage, and agriculture. Click "Advance year" to see how the reef responds to these changes. 5 Minute Preview

Coral Reefs 2 - Biotic Factors

In this followup to the Coral Reefs 1 - Abiotic Factors activity, investigate the impacts of fishing, disease, and invasive species on a model Caribbean coral reef. Many variables can be manipulated, included intensity of fishing, presence of black band and white band disease, and the presence of actual and potential invasive species. Click "Advance year" to see the impacts of these biotic changes. 5 Minute Preview

Greenhouse Effect - Metric

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 amount of greenhouse gases present in the atmosphere can be adjusted through time, and the long-term effects can be investigated. 5 Minute Preview

Pond Ecosystem

Measure the temperature and oxygen content of a pond over the course of a day. Then go fishing to see what types of fish live in the pond. Many different ponds can be investigated to determine the influence of time, temperature, and farms on oxygen levels. 5 Minute Preview

Dichotomous Keys

Use dichotomous keys to identify and classify five types of organisms: California albatrosses, Canadian Rockies buttercups, Texas venomous snakes, Virginia evergreens, and Florida cartilagenous fishes. After you have classified every organism, try making your own dichotomous key! 5 Minute Preview

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

Paramecium Homeostasis

Observe how a paramecium maintains stable internal conditions in a changing aquatic environment. Water moves into the organism by osmosis, and is pumped out by the contractile vacuole. The concentration of solutes in the water will determine the rate of contractions in the paramecium. 5 Minute Preview

Dichotomous Keys

Use dichotomous keys to identify and classify five types of organisms: California albatrosses, Canadian Rockies buttercups, Texas venomous snakes, Virginia evergreens, and Florida cartilagenous fishes. After you have classified every organism, try making your own dichotomous key! 5 Minute Preview

Flower Pollination

Observe the steps of pollination and fertilization in flowering plants. Help with many parts of the process by dragging pollen grains to the stigma, dragging sperm to the ovules, and removing petals as the fruit begins to grow. Quiz yourself when you are done by dragging vocabulary words to the correct plant structure. 5 Minute Preview

Germination

Plant seeds and watch how many sprout. Examine what factors affect germination. Vary the amount of heat, water, and light the seeds get. Practice designing controlled experiments and using the scientific method. 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

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

Coral Reefs 1 - Abiotic Factors

Explore the abiotic factors that affect Caribbean coral reefs. Many factors can be manipulated in this simplified reef model, including ocean temperature and pH, storm severity, and input of excess sediments and nutrients from logging, sewage, and agriculture. Click "Advance year" to see how the reef responds to these changes. 5 Minute Preview

Coral Reefs 2 - Biotic Factors

In this followup to the Coral Reefs 1 - Abiotic Factors activity, investigate the impacts of fishing, disease, and invasive species on a model Caribbean coral reef. Many variables can be manipulated, included intensity of fishing, presence of black band and white band disease, and the presence of actual and potential invasive species. Click "Advance year" to see the impacts of these biotic changes. 5 Minute Preview

Coral Reefs 1 - Abiotic Factors

Explore the abiotic factors that affect Caribbean coral reefs. Many factors can be manipulated in this simplified reef model, including ocean temperature and pH, storm severity, and input of excess sediments and nutrients from logging, sewage, and agriculture. Click "Advance year" to see how the reef responds to these changes. 5 Minute Preview

Coral Reefs 2 - Biotic Factors

In this followup to the Coral Reefs 1 - Abiotic Factors activity, investigate the impacts of fishing, disease, and invasive species on a model Caribbean coral reef. Many variables can be manipulated, included intensity of fishing, presence of black band and white band disease, and the presence of actual and potential invasive species. Click "Advance year" to see the impacts of these biotic changes. 5 Minute Preview

Dichotomous Keys

Use dichotomous keys to identify and classify five types of organisms: California albatrosses, Canadian Rockies buttercups, Texas venomous snakes, Virginia evergreens, and Florida cartilagenous fishes. After you have classified every organism, try making your own dichotomous key! 5 Minute Preview

Dichotomous Keys

Use dichotomous keys to identify and classify five types of organisms: California albatrosses, Canadian Rockies buttercups, Texas venomous snakes, Virginia evergreens, and Florida cartilagenous fishes. After you have classified every organism, try making your own dichotomous key! 5 Minute Preview

Homeostasis

Control a simulated person running on a treadmill. Your challenge is to use clothing, exercise, and sweat to maintain a constant body temperature as air temperature goes up and down. Sweating (perspiration) can be controlled automatically by the Gizmo or, for a challenge, manually by the user. Don't forget to eat and drink! 5 Minute Preview

Human Homeostasis

Adjust the levels of clothing, perspiration, and exercise to maintain a stable internal temperature as the external temperature changes. Water and blood sugar levels need to be replenished regularly, and fatigue occurs with heavy exercise. Severe hypothermia, heat stroke, or dehydration can result if internal stability is not maintained. 5 Minute Preview

Circulatory System

Trace the path of blood through a beating heart and the network of blood vessels that supplies blood to the body. Take blood samples from different blood vessels to observe blood cells and measure the levels of oxygen, carbon dioxide, sugar, and urea. 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

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

Digestive System

Digestion is a complex process, involving a wide variety of organs and chemicals that work together to break down food, absorb nutrients, and eliminate wastes. But have you ever wondered what would happen if some of those organs were eliminated, or if the sequence was changed? Can the digestive system be improved? Find out by designing your own digestive system with the Digestive System Gizmo. 5 Minute Preview

Drug Dosage

A drug prescription must be carefully planned to maximize benefit while avoiding an overdose. In this Gizmo, you can give a patient one or more pills and monitor the levels of medication in the body through time. Based on the reaction of the patient, determine the ideal levels of medication. Create a dosage schedule so these levels are maintained through time. Four types of pills, each with a different release pattern and target organ, are available for use. 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