What are the three most common states of matter?
Solid, liquid, gas
What is the main difference between viruses and bacteria?
Viruses require a host cell to reproduce; bacteria are living cells
What are the four basic needs of all organisms in an ecosystem?
Food, water, shelter, space
What is a trait?
A characteristic of an organism
What is relative dating?
Determining age by comparing rock layers
What subatomic particle determines the identity of an element?
Protons
Which type of pathogen causes athlete's foot?
Fungus
What is the difference between a biotic factor and an abiotic factor?
Biotic = living; abiotic = nonliving
What is an adaptation?
A trait that improves survival
What is an index fossil?
A fossil used to identify the relative age of rock layers
How can you determine the number of neutrons in an atom?
Atomic mass − atomic number
Why are antibiotics effective against bacterial infections but not viral infections?
Antibiotics target bacteria, not viruses
Why are producers important in a food web?
They make food through photosynthesis
How does natural selection help species survive?
Individuals with helpful traits survive and reproduce more
According to the Law of Superposition, which rock layers are oldest?
The bottom layers
What is the difference between a physical change and a chemical change?
Physical changes do not create a new substance; chemical changes do
What is one way vaccines help prevent disease?
They help the immune system recognize pathogens
What happens to available energy as it moves through a food web?
Energy decreases as it moves up trophic levels
Give one piece of evidence that supports the theory of evolution.
Fossils, DNA evidence, homologous structures, embryology
How do fossils provide evidence of Earth's past?
They show past organisms and environments
Explain the Law of Conservation of Mass during a chemical reaction.
Matter is not created or destroyed; reactants equal products
What is the difference between an epidemic and a pandemic?
Epidemic = regional outbreak; pandemic = worldwide outbreak
How are the water cycle and carbon cycle connected to living organisms?
Organisms use and recycle water and carbon
Why do populations change over long periods of time?
Natural selection and environmental changes
What evidence supports the theory of plate tectonics?
Fossils, rock matches, continental fit, seafloor spreading