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Genetic Engineering (Student Edition)
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Genetically engineered crops cross boundaries that traditional crops do not and pose new and challenging regulatory issues. In the United States, a number of government agencies regulate food, plants, pesticides, and…
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Sweet Genes in Corn (Student Edition)
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One of the joys of summer is sweet, fresh, crisp corn on the cob. Most corn is starchy and usually does not taste sweet. Why isn't corn on the cob starchy? What makes sweet corn sweet? Find the answers in this chapter…
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Centers of Diversity (Student Edition)
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What country do you think is the origin of the tomato? In this chapter, tables and graphs are used to understand the relationship between food plants and the biomes they originated in. Plant centers of origin are…
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Quantitative Traits (Student Edition)
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This chapter focuses on Quantitative trait loci (QTL) studies—a way of investigating quantitative traits where many genes have an effect on a trait. The studies help plant breeders find the genes involved in…
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Galileo's track is made from one long continuous rail that joins two different angled ramps together. The first ramp has a short, steep slope. After a ball rolls down the first ramp, it will then roll up a longer gently…
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In the demonstration in this chapter, a person holds a large foam board and a small brass weight to compare their respective weights. After hefting both objects for a few moments, the person is asked to determine which…
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This chapter features small wooden or cardboard boxes that hang about 5 feet from the ceiling on a short length of string. A second string comes out of the bottom of the boxes. The purpose of the boxes is not…
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Blowing up a balloon inside a bottle is difficult if there is no place for the air to be displaced. Once a balloon is blown up inside the bottle, the balloon remains blown up even with the mouth of the balloon wide open…
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In this chapter, a board is set up with three surfaces. The students' hands compare the relative temperature of the surfaces on the board, and the board prompts students to investigate by asking them to determine which…
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In this chapter, the words "What color is inside?" appear around a hole on top of a can. The outside is multicolored, indicating that any of a number of colors could be inside. If students look through the hole, it…
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The device in this chapter shows how a thermostat works by turning a lightbulb on and off as the thermostat responds to the heat of the bulb. It can use a gum wrapper or a strip made from paper and aluminum foil to act…
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This chapter focuses on the use of some very simple materials to produce an electric motor with which to demonstrate the principles of magnetism. A variation of the simple motor replaces the usual ceramic magnet with a…
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The principle of a lightbulb can be demonstrated without the danger of creating a vacuum inside a glass jar. One of the difficulties in demonstrating a lightbulb centers on the removal of air from the chamber using a…
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Tops are ancient toys that have been spinning around for thousands of years. Their movement—fascinating to watch—appeals to the child in all of us, and the action and the study of tops appeal to a wide range of age…
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Newton's first law of motion describes the resistance of an object to change in the speed and direction of its motion. The law also holds that objects will resist being put into motion. This concept is described as…
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