Organisms & Ecosystems
Which statement best defines an organism?
A. A group of different species living in one area
B. A living thing that carries out life processes such as growth and reproduction
C. A nonliving part of an ecosystem such as water or soil
D. A system of energy transfer between predators and prey
B. A living thing that carries out life processes such as growth and reproduction
Which statement best defines a trait?
A. A learned behavior that all organisms develop over time
B. A characteristic or feature of an organism that can be inherited or observed
C. A type of ecosystem where organisms live
D. The process of breaking down dead organisms
B. A characteristic or feature of an organism that can be inherited or observed
What is an atom?
A. A substance made of two or more different elements bonded together
B. The smallest unit of an element that still has the properties of that element
C. A group of organisms living in one ecosystem
D. A type of chemical reaction product
B. The smallest unit of an element that still has the properties of that element
What is the difference between kinetic energy and potential energy?
A. Kinetic energy is stored energy, while potential energy is energy of motion
B. Kinetic energy is energy of motion, while potential energy is stored energy
C. Both are the same type of energy
D. Potential energy only happens in living things
B. Kinetic energy is energy of motion, while potential energy is stored energy
Which statement best describes a force?
A. A material that cannot be changed
B. A push or pull on an object, such as kicking a ball
C. The energy stored in food
D. A type of chemical change
B. A push or pull on an object, such as kicking a ball
What is the main difference between a producer and a consumer in an ecosystem?
A. Producers break down dead organisms, while consumers make their own food
B. Producers obtain energy by eating other organisms, while consumers use sunlight
C. Producers make their own food, while consumers get energy by eating other organisms
D. Producers and consumers both get energy only from sunlight
C. Producers make their own food, while consumers get energy by eating other organisms
Where do we get genes from, and what do they provide instructions for?
A. We get genes from the environment, and they instruct how ecosystems function
B. We get genes from food, and they instruct how to grow taller
C. We get genes from parents, and they provide instructions for making proteins and traits
D. We get genes from sunlight, and they control weather patterns
C. We get genes from parents, and they provide instructions for making proteins and traits
Which statement best describes a molecule?
A. A single particle of energy
B. Two or more atoms chemically bonded together
C. A mixture of different substances that are not bonded
D. The smallest unit of a compound only
B. Two or more atoms chemically bonded together
In the equation:
CO₂ + CaO → CaCO₃
Which are the reactants?
A. CaCO₃ only
B. CO₂ and CaO
C. CO₂ only
D. CaO and CaCO₃
B. CO₂ and CaO
Which statement best describes gravity?
A. A force that pushes objects away from Earth
B. A force that slows down moving objects
C. A force that pulls objects toward Earth
D. A force created only by machines
C. A force that pulls objects toward Earth
What do we call an organism at the top of the food chain?
An apex predator
Which statement best describes natural selection?
A. Organisms choose the traits they want to pass on to their offspring
B. Organisms with helpful traits are more likely to survive and reproduce over time
C. All organisms in a population change at the same time to match their environment
D. Organisms stop reproducing when the environment changes
B. Organisms with helpful traits are more likely to survive and reproduce over time
Which statement best describes a compound?
A. A substance made of only one type of atom
B. A group of organisms working together
C. A substance made of two or more different elements chemically bonded together
D. A mixture that can be easily separated
C. A substance made of two or more different elements chemically bonded together
Which statement best describes the difference between mass and weight?
A. Mass is the force of gravity; weight is the amount of matter
B. Mass is the amount of matter; weight is the force of gravity on an object
C. Mass changes depending on location; weight does not
D. Mass and weight are exactly the same thing
B. Mass is the amount of matter; weight is the force of gravity on an object
What is friction?
A. A force that speeds up moving objects
B. A force that occurs only in water
C. A force that resists motion between two surfaces
D. A force that creates light energy
A force that resists motion between surfaces.
A rabbit eats grass, and a fox eats the rabbit. Which statement BEST describes this relationship?
A. The rabbit is a producer and the fox is a decomposer
B. The grass is a consumer and the fox is a producer
C. The rabbit is a primary consumer and the fox is a secondary consumer
D. The fox is a producer and the rabbit is a decomposer
C. The rabbit is a primary consumer and the fox is a secondary consumer
A population of birds lives in a forest. Some birds have longer beaks that allow them to reach insects inside tree bark, while others have short beaks. Over time, most birds in the population have long beaks.
What is the BEST explanation?
A. Birds chose to grow longer beaks to survive
B. Birds with longer beaks survived and reproduced more
C. All birds changed their beaks at the same time
D. The environment caused beaks to shrink
B. Birds with longer beaks survived and reproduced more
Which statement best describes the difference between an element and a compound?
A. An element is made of different types of atoms; a compound is made of only one type
B. An element is always a liquid; a compound is always a solid
C. An element is one type of atom, while a compound is two or more different elements chemically bonded
D. An element is a mixture, while a compound is not
C. An element is one type of atom, while a compound is two or more different elements chemically bonded
Explain how energy changes when a ball is dropped from a height. Use the terms potential energy, kinetic energy, gravity, and motion
A student pushes a box across the floor. The box moves at a constant speed in a straight line.
Which statement BEST explains this motion?
A. The forces acting on the box are unbalanced, causing it to speed up
B. Gravity is stronger than the pushing force
C. The forces acting on the box are balanced, so there is no change in motion
D. There is no friction acting on the box
C. The forces acting on the box are balanced, so there is no change in motion
How does energy move through an ecosystem? Name all four parts in order.
C. Sun → producers → consumers → apex >decomposers
A sudden drought causes many plants in an ecosystem to die. What is the MOST likely effect on the ecosystem?
A. The number of producers will increase
B. The number of consumers will decrease
C. The number of decomposers will immediately disappear
D. All organisms will adapt instantly
B. The number of consumers will decrease
A scientist combines two elements: hydrogen and oxygen. A new substance (water) is formed.
Which statement BEST explains this change?
A. The atoms disappeared and new ones were created
B. The atoms rearranged to form a new substance
C. The elements stayed exactly the same
D. The atoms were destroyed during the reaction
B. The atoms rearranged to form a new substance
Which observation best indicates a chemical reaction has occurred?
A. A change in color or gas being produced
B. Ice melting into water
C. A rock being broken into smaller pieces
D. Water being poured into a cup
A. Color change, gas production, temperature change, precipitate formation
Two objects of the same size but different masses are dropped at the same time from the same height. One object is heavier.
Which statement BEST explains what will happen?
A. The lighter object will fall faster because it has less mass
B. The heavier object will fall faster because it has more gravity pulling on it
C. The heavier object will not fall at all
D. Both objects will fall at the same rate because gravity acts equally on them
D. Both objects will fall at the same rate because gravity acts equally on them