Name: Date: Period
Chapter 1 Vocabulary Text
1. Have you ever tried to solve a problem or fix something? Whether you realize it or not, you use a series of steps to solve that problem. Scientists use critical thinking skills to try to solve problems and answer questions. In science, this organization often takes the place of a series of steps of procedures called Scientific Method. Scientific Method is a series of steps used to solve a problem. There are 7 steps in the Scientific Method.
2. Have you ever had a guess on how to solve a problem or how to answer your question? If you have then you have made a hypothesis. A hypothesis is a prediction (or guess) that can be tested. It is your guess on how to solve your problem.
3. Whenever you are completing an experiment you have to have something in the experiment that does not change. Say for example, if you are experimenting on plant growth due to the amount of sunlight, you need to have the same plants with the same soil and pots. The things in the experiment that do not change and remain constant are the controls of the experiment. A control is a standard to which the outcome of the test is compared.
4. With the same experiment mentioned in #3, the amount of sunlight in your experiment can change with each plant to figure out how much sunlight is good for the plant. The part of the experiment that you are testing and that does change is called the variable.
5. After scientists have performed an experiment many, many times and they always get the same results, their hypothesis can then become a theory. A Theory is an explanation of things or events based on scientific knowledge that is the result of many observations and experiments. It is important to remember that theories are not fact and they can change.
6. Gravity! You know it as the force that makes everything fall when you drop something. This will never change. Gravity is an example of a Scientific Law. A Scientific Law is a statement about how things work in nature that seems to be true all the time.
7. Are you alive? Is a plant alive? Yes these things as well as microscopic bacteria to giant trees are all alive. Any living thing is called an organism. All organisms have certain characteristics that are in common with one another, such as reacting to stimuli, growing and developing, organized by being made of cells, using energy, reproducing, and the ability to exchange gases.
8. Living things are made of small units called cells. A cell is the smallest unit of an organism that carries on the functions of life. Some organisms are made up of just one cell, while others are made up of many cells. As humans, we are made of trillions of cells! Every cell has complex structures inside them that do jobs and each cell has information in it that tells it what to do.
9. Living things respond to the environment around them. We sweat when it gets hot outside because our body is reacting to try to cool itself off from the heat. All organisms must work to control what is going on inside their body compared to what is going on outside their body. An organism’s ability to keep the proper conditions (maintain a steady condition) inside no matter what is going on outside the organism is called homeostasis.
10. When scientists first started studying living things they first thought that life just appeared. For example they thought that earthworms just fell from the sky as it rained. Where do you really think they came from? The idea that living things come from nonliving things is known as spontaneous generation.
11. In the mid-1800s, the work of Louis Pasteur, a French scientist, provided enough evidence to disprove the theory of spontaneous generation. He stated that all living things come from other living things. This new theory is called biogenesis. Biogenesis is the theory that living things come only from other living things.
12. Scientists organize living things. They use similarities in structure to classify organisms. They study fossils, hereditary information, and early stages of development to help group organisms. They use this information to determine an organism’s phylogeny. Phylogeny is the organism’s evolutionary history which tells how the organism has changed over time.
13. When scientists group living things, they first put them into large groups. For example, you would first put all your clothes in big groups and then organize them based on certain characteristics into smaller groups. The first and largest group in the classification system is called a kingdom. Kingdoms are divided into smaller groups. The smallest group is called a species.
14. When grouping organisms, scientists give all living things their own special scientific name. Just like you have a special common name (First and Last name), all organisms including you also have a scientific name. The two-word naming system used to name organisms is called binomial nomenclature. The first word of the naming system is Genus and the second word is Species. Your scientific name is Homo sapiens. “Homo” would be your Genus and “sapiens” would be your species.
15. The first word of the two-word naming system identifies the genus of the organism. A genus is a group of similar species. The second word of the name might tell you something about the organism, like what it looks like or where it is found.