Life on Earth Exam 1

Define Science.

The use of objective problem solving methods to observe the natural world and arrive at reasonable explanations of how the world works.

What can science be used to study?

Phenomena that can be observed and measured.

What are some things science cannot measure?

Things that can’t be objectively measured or observed, such as beliefs.

List the activities involved in the scientific process.

Make observations, come up with possible explanations (hypothesis), make predictions based on hypothesis, test predictions in experiments, decide if results allow acceptance, rejection, or revision of the hypothesis, share results.

Why is science considered a process of elimination?

Scientists eliminate non-valid explanations and keep others for further consideration.

What is a hypothesis?

A proposed explanation that can be tested and may be rejected.

What is a scientific theory?

A hypothesis that has been repeatedly tested and has not been rejected.

What is taxonomy?

The process of identifying and classifying species.

What are the levels of taxonomic classification from largest to smallest?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

What are the two parts of a scientific name?

Genus and species/epithet.

Define biodiversity.

All organisms alive today or in the past due to over 3.5 billion years of evolution.

What are protists?

Eukaryotes that are not plants, animals, or fungi, usually tiny aquatic organisms.

What is the key evidence that all living things descended from common ancestors?

All living things are made of the same chemical elements and basic molecules.

Define biogeography.

A branch of science that attempts to explain the distribution of species on Earth.

What is the relationship between DNA differences and evolutionary divergence?

The longer two species have diverged, the more DNA differences are expected.

What is significant difference in experimental results?

How likely it is that the results occurred due to the effects of the independent variable.

What assumption can be made about similar body structures?

They are assumed to be closely related due to inheritance from a common ancestor.

What is endosymbiosis?

An intimate relationship where one species lives inside another, crucial for the origin of organelles like mitochondria and chloroplasts.

What distinguishes toothed whales from baleen whales?

Toothed whales have evolved organs for echolocation; baleen whales have lost teeth and evolved structures to filter feed.

Explain why controls are necessary in an experiment.

To determine if the independent variable has an effect on the dependent variable.