Unit 1: Matter, Atoms, & Reactions
Classroom desks, oxygen in the air, water molecules, and living things all belong in this category because they have mass and occupy space.
What is matter?
This organelle stores DNA in all Eukaryotic cells
What is the nucleus?
A section of DNA responsible for a trait.
What is a gene?
A group of organisms of the same species living in the same area.
What is a population?
A push or pull on an object.
What is a force/applied force?
The two particles located in the center of an atom, while electrons move outside that center.
What are neutrons and protons?
Cells use this organelle to create energy from food.
(Hint: It's "Mighty")
What is the mitochondria?
These represent the various ways in which changes in DNA can impact a person or population of people. Their impact on a species can depends on how well that species can adapt to its environment.
What are beneficial, neutral, and harmful mutations?
This type of organism converts sunlight into stored chemical energy.
What is a producer?
Forces that do not cancel each other out and cause a change in motion.
What are unbalanced forces?
This concept explains why the mass before and after a reaction should stay the same because atoms are rearranged, not lost.
What is the Law of Conservation of Mass?
Sweating, shivering, breathing, and moving nutrients are examples of the body trying to keep internal conditions stable.
What is homeostasis?
These inherited variations of genes help explain why children may share distinct features with biological parents/relatives.
What are Alleles?
The largest population an environment can support.
What is carrying capacity?
This law states that for every action force, there is an equal and opposite reaction force.
What is Newton’s Third Law?
A student says, “When wood burns, matter disappears because the wood gets smaller.” Explain why this statement is scientifically incorrect.
(Some variation of the following) The statement is incorrect because:
Matter is not destroyed during burning (Law of Conversation of Mass).
The wood changes into new substances, including gases, ash, and heat/light energy being released.
The atoms are rearranged, but the total matter is conserved.
A red blood cell and a nerve cell have very different shapes. Explain why this difference is useful for a multicellular organism.
(Some version of the following): Specialized Cells have different shapes help cells perform different jobs more efficiently. A red blood cell is shaped to carry oxygen, while a nerve cell is long and can send signals.
Two parent both have the Dominant and Recessive alleles for eye-color. What is the likelihood that an offspring will have two copies of the recessive allele? Demonstrate with a Punnet Square.
(Some version of the following): 25%
R r
R RR Rr
r Rr rr
If the trophic level of producers in an ecosystem have 40,052 Joules of available energy, how much available energy will tertiary consumers have in an energy pyramid? What ideas explains why tertiary consumers have this energy?
(Some version of): 40.052 Joules of available energy. Tertiary consumers have much less energy because most energy is used by organisms for life processes. The rest is released as heat. This explains why energy decreases as it moves up each level of an energy pyramid.
An two astronauts accidentally collide into one another while floating in their ship in zero-gravity. Explain what will happen to both astronauts if they collide into one another with the same force. Describe which Law of Motion is responsible for what will happen
(Some version of this): If two astronauts collide with the same force while floating in zero gravity, both astronauts will push away from each other in opposite directions. This happens because of Newton’s Third Law, which states that every action force has an equal and opposite reaction force.
A student places an iron nail outside for several weeks. Later, the nail is covered in rust and looks like a different material. Explain whether this is a physical or chemical change, and connect your answer to atoms and new substances.
(Some version of the following): This is a chemical change because:
Rust is a new substance that forms when iron reacts with oxygen. The atoms are rearranged into a different substance, but the matter is not destroyed. This connects to conservation of mass because the atoms are still present, just combined in a new way.
A scientist finds a cell with a nucleus, chloroplasts, a cell wall, cytoplasm, and mitochondria. Is this most likely a plant cell or animal cell? Use evidence.
(Some version of the following): It is likely a plant cell because it has chloroplasts and a cell wall. Plant and animal cells can both have a nucleus, cytoplasm, mitochondria, and a cell membrane, but chloroplasts and cell walls are structures usually found in plant cells, not animal cells.
A population of insects lives on dark tree bark. A mutation causes some insects to become darker in color. Explain how this mutation could affect survival and reproduction.
(Some version of the following): The darker insects may be harder for predators to see on dark bark. If they survive longer, they may reproduce more and pass that trait to offspring. Over time, the darker trait may become more common if it helps survival.
A hawk population is reintroduced into a grassland ecosystem after being absent for many years. Predict how this change could affect the mouse population, the amount of grasses/seeds, and other organisms in the food web. Identify the term this scenario is describing. Explain your reasoning.
(Some version of): If hawks return, the mouse population may decrease because hawks prey on mice. With fewer mice eating grasses and seeds, the amount of grasses/seeds may increase. This can affect other organisms that depend on those plants or compete with mice, showing a trophic cascade because one population change (Hawks) causes effects throughout the food web.
A balloon racer moves along a string when air escapes from the balloon. Explain what force causes the motion and whether the forces are balanced or unbalanced.
The escaping air pushes backward out of the balloon, and the balloon moves forward in the opposite direction. This shows Newton’s Third Law because the air pushes one way and the balloon moves the other way. The forces are unbalanced because the balloon changes motion and moves along the string.