Scientific Method
The study of life
What is the key to good science? Define it.
Objectivity is the key to good science.
To be objective, experiments need to be designed and conducted in a way that does not introduce bias into the study.
What is the smallest unit of life?
Cell
What is an example of a unicellular animal?
What is matter and what is it composed of?
Refers to anything that takes up space and has mass
Composed of elements
What is a Hypothesis? Can it be proven?
A possible explanation for an event. It cannot be proven
What is bias? What are the two main types?
A prejudiced presentation of material. A consistent error in estimating a value
1) Sampling Bias
2) Measurement Bias
What are the two types of reproduction? Describe them.
Asexual and sexual
What carries hereditary information and what are they made of?
Genes, DNA
What are the subatomic particles, their charges, and their locations?
Neutrons—no electrical charge, found in nucleus
Protons—positive charge, found in nucleus
Electrons—negative charge, found outside of nucleus
What is the difference between qualitative and quantitative observations?
Define a sample and sampling bias.
Sample: A group of units selected to be “measured” from a larger group (the population).
Sampling bias: is introduced when the sample used is not representative of the population or inappropriate for the question asked.
What is anabolism? What is catabolism?
1) The process of building up complex substances from simpler substances
2) The process of breaking down complex substances into simpler substances to release energy
What are examples of stimuli that animals respond to?
Light, Temperature, Odor, Sound, Gravity, Heat, Water, Pressure
What are elements? How many naturally occurring ones are there? Which elements make up 90% of the human body weight?
1) Element—substance that cannot be broken down into another substance by ordinary chemical means
2) Only 92 naturally occurring elements
3) Four elements make up about 96% of the body weight of most living organisms—carbon, hydrogen, oxygen, and nitrogen
How can you evaluate the quality of scientific information?
The most reliable scientific information is published in scientific journals, but it is often difficult to understand.
Reliable books are written by scientists and others who are knowledgeable about a particular field.
Reliable Internet sources are government and academic web pages. Commercial web pages are often unreliable because they are trying to sell something.
What are sources of data? Do all organizations produce unbiased data?
University Research, Corporate Research, Government Research, Research by Special Interest Groups
Yes
What does it mean to maintain homeostasis? What is metabolism?
1) A stable state of conditions in the body that are necessary for life
2) The total of all chemical reactions in an organism
What is adaptation? Give an example.
A process that enables organisms to become better suited to their environment. Species obtain adaptations through evolution over great periods of time
Desert plants have succulent waxy leaves and stems to store water and reduce water loss
What are the types of chemical bonds? (include descriptions of molecules and compounds)
Molecule - group of atoms bonded together
Compound - molecule containing atoms of more than one element
Chemical bonds: ionic, covalent
What are the steps of the scientific methods? Explain each one.
1) Define a problem or ask a question
2) Form a hypothesis and make a prediction
3) Do research and plan an investigation
4) Identify variables
5) Perform experiment & collect and organize data
6) Interpret and analyze data and information
7) Draw and defend the conclusion
What are some characteristics of good scientific investigations?
Scientific observations should be well-documented and have supporting evidence.
In an experiment, the variables should be controlled as much as possible.
Experiments should be repeated multiple times by the original investigator.
Scientific investigations should also be able to be replicated by scientists not involved with the original work.
Before publishing a study, scientific journals ask other scientists to review the article. This is called peer review.
What are properties that all living things share?
Cellular Organization, Reproduction. Metabolism (Obtain and Use Energy), Homeostasis, Heredity, Responsiveness, Growth and Development, Adapt Through Evolution
Give an example/describe of each of the characteristics of living things
Answers will vary
Describe the structure and properties of water (use as much detail as possible)
Structure:
•Polar covalent bond
-Atoms do not share electrons equally.
-Oxygen is more electronegative than hydrogen.
-Electrons spend more time around the oxygen nucleus than the hydrogen nuclei.
-Oxygen end becomes slightly negative/hydrogens become slightly positive—NOT an ionic bond or ions
•Hydrogen bond—slightly positive hydrogen of one water molecule attracted to the slightly negative oxygen in another water molecule
Properties:
•Solvency
•Cohesion and adhesion
•High surface tension
•High heat capacity
•High heat of vaporization
•Varying density