Variables
In an experiment, what is the group that is either treated as "normal" or receives no treatment as a means for comparison?
Control group
Determine if the following measurements are accurate, precise, both, or neither. Actual value = 5.5 cm
Student measurements: 3.7 cm, 12.6 cm, and 1.5 cm
Neither
What is the smallest part of an element that can still retain the properties of that element?
Atoms
How can we describe a molecule that likes water? Use two terms in your answer.
Hydrophilic and polar
List the four types of macromolecules.
Carbohydrates, lipids, nucleic acids, and proteins
A student tests whether fertilizer affects plant growth. Name two constants that would be good for this experiment.
A student measures a plant to be 15 cm tall. Is this a qualitative observation, a quantitative observation, or an inference?
Quantitative observation
Bonus (100 pts): give an example of an inference the student could make from this observation.
What type of bond forms when electrons are shared between atoms?
Covalent bond
List the 5 special properties of water that make it ideal for supporting life
Cohesion, adhesion, high specific heat, less dense as a solid, and excellent solvent
Which macromolecule makes up enzymes?
Proteins
State an example of a hypothesis for how the amount of sleep impacts test performance.
"If a student gets more sleep, then they will perform better on their test."
Jaime wants to create a graph displaying how many freshmen are 13, 14, and 15 years old. Which type of graph would be best to represent this data?
Bar graph (pie chart would work if values were converted to percentages!)
Sodium (Na) transfers one electron to chlorine (Cl). What type of bond is formed, and why?
This is an ionic bond due to the transfer of electrons.
Bonus (100 pts): Which type of bond is the strongest in a living thing?
A plant moves water from its roots up to its leaves due to attraction between the water and tissues of the plant, as well as attractions between the water molecules themselves. What properties of water can this be attributed to?
Why are lipids better than carbohydrates for long-term energy storage?
Lipids store 9 cal/g as opposed to carbs' 4 cal/g
A student claims, “Drinking more caffeine makes people type faster.” What are the independent and dependent variables in this claim?
IV - amount of caffeine
DV - typing speed
Rahul is doing an egg drop experiment. The plain egg dropped from the roof of the school breaks, as well as the egg with paper wrapped around it. The egg wrapped in bubble wrap with a mini-parachute does not break. What would be an example of a hypothesis that supports Rahul's findings?
If an egg is dropped from the roof with more protection, then it will not break.
Why is water considered a polar molecule?
The oxygen in water shares the electrons unequally ("hogs the electrons") making the region around oxygen slightly negative while the areas around hydrogen are slightly positive. This unequal distribution of charge is descriptive of a polar molecule.
Salt is often spread on icy roads in the winter. The salt dissolves into the thin layer of water on the road and lowers the freezing point, which helps melt the ice. Which property of water allows the salt to dissolve? How could we classify the salt based on this?
Universal solvent
Salt is polar and hydrophilic as a result
Proteins are made of long chains of amino acids, but each protein folds into a unique shape. Why is it important that proteins can fold into many different shapes, instead of all folding the same way?
Proteins have a variety of jobs; they literally "run your body." In proteins, form dictates function, meaning the shape determines the job of the protein.
A group of students tests whether listening to music affects test scores, but one group takes the test in the morning while the other takes it in the evening. Explain why this is a problem and how it could be fixed.
Problem: there are two independent variables here (music and time of day) so it won't be possible to tell which one caused the dependent variable (effect).
Fix: Test at the same time of day to see how music impacts their performance.
You are given a data table from an experiment, but some values look very different from the rest (these would be called "outliers"). How could this affect the conclusion, and what should you do about it?
These outliers can skew the results/conclusion drawn from them. You should ask the experimenters to repeat the experiment or thoroughly check for error.
Polymers, like DNA and polypeptides, are both made of long chains of monomers held together by covalent bonds. Why are covalent bonds so important in forming these macromolecules?
Covalent bonds are the strongest bonds in living things, preventing polymers from falling apart.
Predict how life in lakes would change if ice were denser than liquid water.
Ice would sink in the winter, causing lakes to freeze all the way through, killing organisms that live in the lake.
A scientist discovers an unknown molecule made of carbon, hydrogen, oxygen, nitrogen, and phosphorus. It stores genetic information. What type of macromolecule is it, and what reasoning supports your answer?
Nucleic acid
Contains C, H, O, N, and P, and stores genetic information, both of which describe nucleic acids.