Seventh grade review Quiz # 1

What is the Law of Superposition?

• A) Older rocks are found at the top of a sequence of layers.

• B) Younger rocks are found at the bottom of a sequence of layers.

• C) In undisturbed layers of rock, the oldest layers are at the bottom.

• D) The age of a rock does not affect its position in the sequence.

Answer explanation

What is half-life?

• A) The time it takes for half of a substance to decay.

• B) The time it takes for all of a substance to decay.

• C) The rate at which a substance is created.

• D) The total lifespan of a radioactive element.

Answer explanation

What are radioactive elements?

• A) Elements that are not stable and break down into smaller parts over time.

• B) Elements that cannot be used in medicine.

• C) Elements that do not react with other substances.

• D) Elements that are always found in plants and animals.

Answer explanation

Homologous structures are…

• A) Body parts that have the same structure but different functions. They are similar in different species because they have the same evolutionary origin.

• B) Body parts that perform the same function but have different structures. They are different in different species because they have the same evolutionary origin.

• C) Unused body parts that no longer serve a function. They are different in different species because they have the same evolutionary origin.

• D) Body parts that have the same structure and the same functions. They are similar in different species because they have the same evolutionary origin

Answer explanation

Analogous structures are…

• A) Body parts that have the same structure and function in different species.

• B) Structures with the same function but different evolutionary origins.

• C) Structures that do not perform any function.

• D) Only found in mammals.

Answer explanation

Vestigial structures are…

• A) Body parts that are no longer useful but were useful in the past.

• B) New body parts that help an animal survive.

• C) Structures that help an organism move.

• D) Parts of the body that help an organism reproduce.

Answer explanation

Overproduction in evolution refers to…

• A) The ability of organisms to evolve quickly.

• B) Producing only one offspring at a time.

• C) The creation of new species.

• D) Producing too many offspring, more than can survive.

Answer explanation

Overproduction leads to…

• A) More competition for resources.

• B) More food for organisms.

• C) Less genetic variation.

• D) Fewer predators.

Answer explanation

When species evolve in isolation, it means they…

• A) Share the same habitat and resources.

• B) Have similar characteristics with other species.

• Are separated from other species and evolve differently.

• D) Do not reproduce.

Answer explanation

The Cambrian Explosion was…

• A) The extinction of most species on Earth.

• B) The formation of the first plants.

• C) A sudden increase in the diversity of life on Earth.

• D) A period when no life existed.

Answer explanation