Semester 2 Final Study Guide - Evolution, Human Body Systems, and Ecology

Vocabulary flashcards for review.

Charles Darwin

British naturalist who developed the theory of evolution by natural selection after his research on the HMS Beagle, notably in the Galapagos Islands.

Evolution

The process of biological change over time.

Adaptation

A trait that makes it easier for an organism to survive and reproduce; one of Darwin’s four principles of natural selection.

Natural selection

The process by which certain traits give an organism a fitness advantage, making it easier to survive and reproduce. The trait is naturally selected for and then passed onto future generations.

Variation

Differences in physical, heritable characteristics in an organism compared to others in the same group; one of Darwin’s four principles of natural selection.

Overproduction

The idea that having higher numbers of offspring will increase the likelihood that some survive; one of Darwin’s four principles of natural selection.

Fitness

The measurement of an organism's ability to survive and reproduce.

Descent with Modification

Over time, natural selection will result in species that are better suited to their environment, and those traits will be passed onto future generations.

Selective pressures

A force that causes a specific trait or phenotype to be more beneficial in an environment.

Structural adaptation

External features that increase an organism’s fitness, such as the long claws on marine iguanas.

Behavioral adaptation

Ways an animal acts that increase its fitness, such as being nocturnal or migrating.

Physiological adaptation

Internal changes in an organism that increase its fitness, such as being warmblooded or producing venom.

Vestigial structures

Structures or organs that no longer seem to perform a function, such as the wings of an ostrich.

Homologous structures

Structures found in multiple animals that are structurally similar, but perform a different function, such as the whale of a flipper and the wing of a bird.

Bottleneck effect

A type of genetic drift that occurs when an event drastically reduces the population.

Founder effect

A type of genetic drift that occurs when a small group of individuals is separated from the main populations, and establishes a new population in a new location.

Enzymes

A specific type of protein that speed up chemical reactions inside the body.

Enzyme denaturing

When an enzyme is exposed to an environment outside of its range, which causes the enzyme to change shape and lose its function.

Carbohydrates

Macromolecule that provides quick energy.

Lipids

Macromolecule that provides long term energy storage.

Proteins

Macromolecule used for building new tissue.

Nucleic acids

Macromolecule for storing genetic information.

Esophagus

Tube that carries food from the mouth to the stomach.

Stomach

Organ where partially digested food is further broken down by stomach acid and more enzymes.

Small intestine

Organ where food is broken down one more time with enzymes, and the nutrients are absorbed through the small intestine into the bloodstream.

Large intestine

Organ where any undigested material is concentrated while excess water is absorbed.

Pancreas

Organ that produces enzymes needed to breakdown food.

Gallbladder

Organ that stores excess bile produced by the liver.

Liver

Organ that produces bile, which helps dissolve food in the small intestine.

Chemical digestion

The action of breaking down food particles through enzymes and other biochemicals.

Mechanical digestion

The action of physically breaking down food into smaller particles, such as through chewing.

Ecology

The study of interactions between organisms, and between organisms and their environment.

Niche

The role or job an organism performs in the ecosystem.

Competition

When organisms fight for the same resources. There will always be a winner and a loser.

Predation

When one organism kills and feeds on another organism.

Symbiosis

Two species living closely together through mutualism, commensalism, or parasitism.

Mutualism

A relationship where both species benefit.

Commensalism

A relationship where one species benefits and the other species isn't hurt or helped.

Parasitism

A relationship where one species benefits and the other species is harmed.

Autotroph

An organism that can create its own food, usually through photosynthesis; producers in a food web.

Heterotroph

An organism that cannot create its own food, and needs to eat other organisms for energy; consumers in a food web.

Keystone species

A species that has a disproportionately large impact on its ecosystem. Removal of a keystone species will have catastrophic impacts.

Trophic cascade

The domino effect that occurs when a change in one trophic level effects another trophic level.

Biotic factors

Any living part of the environment that an organism might interact with, such as other plants or animals.

Abiotic factors

Any nonliving factor that shapes an ecosystem, such as temperature or precipitation.

Species

A group of organism that can interbreed.

Population

A group of individuals of the same species living in the same area.

Community

A group of different populations living in the same area.

Ecosystem

All the organisms that live in a place, together with their physical environment (includes all biotic and abiotic factors).

Biome

A group of ecosystems that share similar climates and typical environments.

Biosphere

All the combined portions of the planet where life exists.

Survivorship curve

Shows the number of individuals in a population that survive to a certain age.

Carrying capacity

Refers to the maximum population size an environment can sustainably support.

Food web

Shows the feeding relationships between species in an ecosystem.

Trophic level

Each step on a food web.

10% rule

Refers to how only 10% of energy found in one trophic level, will be transferred up to the next trophic level.

Biomagnification

The increase in substance concentration as it moves up the food chain, from organism to organism.

Bioaccumulation

The increase in substance concentration within one organism throughout its lifetime.

Primary succession

The change in an environment that occurs where no soil or life exists.

Secondary succession

The change in an environment that occurs where a previously established ecosystem has been disturbed.