Lab Equipment & Measurement
What piece of lab equipment is typically used to hold and mix liquids but not for precise measurements?
A beaker
In an experiment, this variable is the one that the scientist deliberately changes.
independent variable
Water has a high specific heat, meaning it can absorb a lot of heat without a significant rise in temperature. How does this property benefit living organisms?
it helps regulate temperature in organisms and environments
Which macromolecule is the primary source of quick energy for cells?
carbohydrates
What term describes a conclusion based on evidence and reasoning?
inference
Which piece of equipment would you use to accurately measure 25 mL of a liquid?
Graduated Cylinder
This group in an experiment does not receive the experimental treatment and serves as a baseline for comparison.
the control group
What causes water to form a meniscus when placed in a graduated cylinder?
adhesion (the attraction between water molecules and the container)
Amino acids are the building blocks of which macromolecule?
proteins
What is the variable that is measured in an experiment?
dependent variable
This tool is commonly used to transfer liquids into containers with small openings.
a funnel
What is the term for a prediction that can be tested through scientific experimentation?
a hypothesis
Why does ice float on water?
because water is less dense as a solid than as a liquid
What type of macromolecule stores genetic information?
nucleic acids
This term refers to the consistency of repeated measurements.
precision
Which piece of lab equipment is never used for making measurements?
test tube
If you were testing the effect of sunlight on plant growth, what would the dependent variable be?
the growth of the plant (measured in height, mass, etc.)
What property of water allows it to dissolve many different substances, making it a "universal solvent"
polarity (water's polar nature allows it to dissolve ionic and polar substances)
Which macromolecule is most involved in forming cell membranes?
lipids
What is the term for a substance that does not mix well with water?
hydrophobic
Explain the difference between accuracy and precision when measuring a liquid in a graduated cylinder.
accuracy refers to how close a measurement is to the true value, while precision refers to the consistency of repeated measurements
Describe an experiment to test the hypothesis: "If students get more sleep, then they will score higher on tests." Include the independent variable, dependent variable, control group, and two constants.
The independent variable is the amount of sleep, the dependent variable is the test scores, the control group is students who get a standard amount of sleep, and constants could include the type of test and the testing environment
Explain how water's cohesion and adhesion properties contribute to capillary action in plants.
cohesion allows water molecules to stick together, and adhesion allows them to stick to the walls of the plant's xylem vessels, helping water travel from roots to leaves
List the order in which the body consumes macromolecules for energy, starting with the first choice.
carbohydrates, lipids, proteins
Explain the difference between an observation and an inference.
an observation is a direct statement based on sensory input, while an inference is a conclusion drawn from observations