Science investigates only
the natural world
________ involves using one or more of the senses to gather information in a carful, orderly way.
A logical interpretation based on prior knowledge and experience is an...
A proposed scientific explanation for a set of observation is a...
Explain the role of prior knowledge in making inferences.
Scientists know that systems in the natural world are consistent in their behavior, so knowledge gained in a previous study can be applied to other systems. Previous knowledge allows scientists to interpret data and observations.
Explain how observation, interpretation, and explanation are important to the study of science.
Scientists use their observation skills to gather data, their inter- pretation skills to understand what was observed, and their explanation skills to explain why the data either supports or disproves a hypothesis.
Explain the difference between qualitative and quantitative observation. Give an example of each one.
An observation is the process of gathering infor- mation about events or processes in a careful, orderly way. An inference is a logical interpretation of data based on prior knowledge or experience.
A student sits down at a computer and presses the power button. The computer does not turn on. What is a logical explanation as to why the computer does not work? How would the student test that idea.
The computer is not plugged into the outlet. A student would need to find the power cord and check to see that it is plugged into an outlet.
What is the difference between observation and inference.
An observation is the use of on or more of the main senses-sight, hearing, touch, smell, and sometimes taste-to gather information. An inference is a logical interpretation of dad based on prior knowledge or experience.
A section of land is devoid of plants. A student stated the following hypotheses: Plants do not grow here because of a lack of sunlight. Is this a valid hypothesis? Explain your answer/
Yes, the hypothesis can be tested; therefore, it is a valid hypothesis.
List some variables that can change in the experiment , and discuss the importance of a control group.
Examples of variables include the objects and equipment used, temperature, time, type of material, and amount of material. The control group and the group in which the variable was altered are com- pared to see if changing the variable had an effect.
Describe a historical experiment performed to test the theory of spontaneous generation. Be sure to identify the control and variable tested.
Pasteur's experiment tested spontaneous generation. Pasteur's control group consisted of open jars, and his experimental variable was nets which kept flies away from the meat. He found out maggots don't just spontaneously spring to live on routing meat, but the flies that swarm the meat lay eggs on the meat.
What is a theory?
A theory is a well-tested explanation that unifies a broad range of observations
Write in order the steps to an experimental investigation in the correct order.
1. Ask a question.
2. Form a hypothesis.
3. Set up a controlled experiment.
4. Record and analyze results.
5. Draw a conclusion.
Why is it necessary for scientists to record and publish their experiments and results?
Scientists need to record and publish their results so that other scientists may also be able to conduct the experiment. Theories are developed from experiments that can be tested again and again to validate the results as facts.
Can an experiment with several variables be used to explain a theory?
Theories are based on well-tested explanations. Experiments that have several variables cannot provide valid explanations, because a scientist cannot be sure whether one vari- able or several variables have consistently produced the experiment's results.
List eight characteristics of living things
1. Living things are made of cells.
2. Living things reproduce
3. Living things are based on a universal genetic code. (DNA)
4. Living things grow and develop.
5. Living things obtain and use material and energy.
6. Living things respond to their environment.
7. Living things maintain a stables internal environment.-Homeostasis
8. Taken as a group, living things change over time.-evolution
The part of earth that contains all ecosystems.
Community and its nonliving surroundings.
Populations that live together in a defined area.
Group of organism of one type that live in the same area.
individual living thing.
Groups of cells
Tissues, organs, and organ systems.
Smallest functional unit of life.
Groups of atoms; smallest unit of most chemical compounds.
Explain one way human being responds to an environmental change in a way that maintains homeostasis.
A human being would respond to an environmental change by shivering when it gets too cold because the muscle action involved in shivering produces heat to warm the body and maintain homeostasis.
Describe a similarity and a difference between unicellular and multicellular organism.
Both unicellular and multicellular organisms display all of the characteris- tics of living things, but unicellular organisms are smaller and made up of only a single cell, while multi- cellular organisms have many cells of different types.
What system of measurement is universal among scientists?
The metric system.
What are the two main types of electron microscopes?
Scanning Electron Microscope (SEM)
Transmission Election Microscope (TEM)
Can be used to view living samples.
Can be equipped to produce real-time images of movement of cells.
Used to view dead and preserved cells.
Both Light and electron microscopes.
Can produce 3-D images of the surfaces of objects.
Group of cells grown in a nutrient solution from a single original cell.
Technique in which cells are broken into pieces and the different cells parts are separated.
If a scientist wanted to study cell responses under varying environmental conditions, what laboratory technique would be appropriate to use?
The scientist should use Cell Cultures because this technique allows a single cell to reproduce so that many cells may then be studied in varied conditions.
If scientist used a different system of measurement and invented his or own tools of measurement, what problems might arise?
If scientist used a different system of measurement and invented his or own tools of measurement other scientist would have trouble interpreting the data and reproducing the experiment.
Cell fractionation and light microscopy can be used to study various organelles. What types of information could each technique provide?
Cell fractionation provides information about the composition of an organelle; light microscopy can give information about the function of an organelle in the living cell. Both can give some information about the relative size of an organelle compared to other components of the cell.
Which value is greater, 10,00 centimeters or 1 Kilometer?
1 Kilometer is equal to 100,000 centimeters
10,000 centimeters is equal to 0.1 kilometers
1 kilometers is greater than 100 centimeters
the idea of living things coming from non-living things
Spontaneous generation Experiments of:
Pasteur - disproved abiogenesis
fission, budding, regeneration, no genetic variation.
requires egg and sperm provides genetic variation.
increase in size and/or number of cells
change leading to maturation
Examples of how living things obtain and use materials and energy.
Digestion of Food
Process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches.
Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen.
Digestion of food
Digestion involves mixing food with digestive juices, moving it through the digestive tract, and breaking down large molecules of food into smaller molecules. Digestion begins in the mouth, when you chew and swallow, and is completed in the small intestine.
Set of chemical reactions through which an organism builds up or breaks downs materials as it carries our its life processes.
Levels of Organization
Cells→ Tissues→ Organs→ Organ Systems→ Organisms
Levels of Organization ( Level 2)
Organism→ Populations→ Communities→ Ecosystems→ Biomes→ Biosphere
1. Cell Culture
2. Cell fractionation
Process by which organisms maintain a relatively stable internal environment.
A logical interpretation of an observation.
A scientific theory is...
a well-tested explanation that unifies a broad range of observations.
An instrument that produces images bye focusing light rays is called?
The term spontaneous generation means that...
living things arise from non-living things.
Compound Light Microscope
can produce a clear image of one-fifth of the diameter of a typical cell.
Use beams of electrons, rather than light, to produce images almost 1000 times more detailed than a light microscope.
The variable that is deliberately changed.
The variable that is observed and that changes in response to the manipulated variable.
Whenever possible, a hypothesis should be tested by and experiment in which only one variable is changed at a time. All other variables should be kept unchanged, or controlled.