What I want to know is....
High school science students have many questions pertaining to their lives and their experiences--about things that worry them, things that interest them, and about the wild and crazy. By giving an opportunity to explore these questions you open the world of science to them.
The Question of Heredity
Students often wonder why they are different from other people, especially from other members of their family. Teaching the basic concepts of heredity helps them to understand why they are who they are, and to allay some of their concerns.
As a teacher it is important to help them understand the basic components of the DNA molecule, how it looks like a ladder with bases making up the rungs. The order of these bases, like letters of a word, makes a message. This message determines a person's appearance and certain elements of personality. To make your point, set up a sentence in code on the board and ask the students to decipher the sentence. Then, change one part of the code and ask them to try again; one minor change can affect the meaning of the message.
Once they understand this it is time to teach them the difference between dominant and recessive alleles (forms of a gene) and how, depending on which alleles they inherit, they can be so different from others in their family. To challenge your students, add the concepts of co-dominance and incomplete dominance along with probability. In the end, they will have a better concept of how they got to be who they are.
The Sun and the Planets and Gravity
Why doesn't the sun's gravity suck the planets into it? This is a common question among students. It is important first to help your students understand that during the formation of the solar system, specifically the sun, an explosion flung planetary debris away from the center (sun). This debris became planets. Now, according to Newton and his law of inertia, these planets should continue in a straight line at a constant speed unless another force acts on it. This other force is gravity. In the end, it is a balancing game with the sun's gravity pulling on the planets and inertia determining that the planets continue outward in a straight line. A good analogy is swinging a ball on a string. The person is the sun, the string is gravity, and the ball is a planet. Let go of the ball and what happens? The ball flies away in a straight line.
The Question of Greenhouse Effect
It is in the news everywhere; our planet is experiencing the Greenhouse Effect. Students hear this and worry, often not understanding what is going on. First, let students know the Greenhouse Effect is a natural phenomenon in which certain atmospheric gases, primarily carbon dioxide, help keep our planet warm. This is a good thing under normal circumstances.
Then explain that it becomes a problem when there are too many of these gases produced. Over time, this can result in flooding, altered weather patterns, destruction of certain wildlife, and negative affects on food crops. Continue to explain how the burning of fossil fuels produces these gases and what they can do to help solve the problem. By helping students become part of the solution you will teach them that they can affect the planet's health.
Tags: Greenhouse Effect, straight line, different from, from other, teach them
