SCIENTIFIC METHOD
This is usually the first step of the scientific process.
observation
The variable that the scientist purposely changes.
Independent variable
Pure water has this pH.
7
Glucose belongs to this major biomolecule group.
Carbohydrates
The four elements most commonly found in living organisms are abbreviated CHON. Name them.
Carbon, Hydrogen, Oxygen, Nitrogen
This is a possible explanation for an observation that can be tested.
Hypothesis
The variable that is measured during an experiment.
Dependent variable
A substance with a pH below 7 is classified as this.
Acidic
Animals store extra glucose in this polysaccharide.
Glycogen
Cell membranes are primarily built from these molecules.
Phospholipids
Put these in order: analyze, observe, conclude, hypothesize, test.
Observe → Hypothesize → Test → Analyze → Conclude
In a medicine experiment, the group receiving a placebo is usually this group.
Control group
Because of its polarity, water is often called the universal ______.
Solvent
Plants primarily store glucose in this polysaccharide.
Starch
The bonds holding hydrogen and oxygen together within a single water molecule are this type.
Polar covalent bonds
If experimental results contradict a hypothesis, scientists say the hypothesis has been ______.
Falsified / Not supported
Scientists expose cells to UV light for 1, 5, 15, or 30 minutes and measure DNA damage. Identify the independent variable.
Length of UV exposure
This property of water helps explain why some insects can walk across the surface of water.
Cohesion
A triglyceride consists of one glycerol joined to three of these molecules.
Fatty Acids
These special proteins speed up chemical reactions in cells.
Enzymes
Explain one major difference between a scientific hypothesis and a scientific theory.
A hypothesis is a testable explanation; a scientific theory is supported by extensive evidence and repeated testing.
A researcher changes the amount of fertilizer and the hours of light given to plants, then measures plant height. Identify the independent and dependent variables.
IVs: fertilizer and light; DV: plant height
Soda has a pH of 4 and coffee has a pH of 5. Which is more acidic, and by how much?
Soda; 10 times more acidic
Lipids generally do not dissolve in water because lipid molecules have this property.
They are nonpolar / hydrophobic
An unsaturated fat is usually in this physical state at room temperature.
Liquid