Biology I Honors, Finals Study Guide

Evolution

The gradual change in a species over time

Adaptation

A trait that helps an organism survive and reproduce

Fitness

Ability of an organism to survive and reproduce in its environment

Species

A group of similar organisms that can breed and produce fertile offspring

Allele Frequency

Number of times that an allele occurs in a gene pool compared with the number of alleles in that pool for the same gene

Darwin's Theory of Evolution

All species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual's ability to compete, survive, and reproduce.

Normal Distribution

A bell-shaped curve, describing the spread of a characteristic throughout a population

Stabilizing Selection

Individuals near the center of a distribution curve have higher fitness than individuals at either end of the curve; bigger curve around the middle

Directional Selection

Occurs when natural selection favors one of the extreme variations of a trait

Disruptive Selection

Occurs when natural selection favors both the higher, and lower, extreme

Gene Flow

The transfer of genetic material (genes) from one population of organisms to another

Bottleneck effect

Occurs when an event drastically reduces population size

Founder effect

Occurs when a few individuals become isolated from a larger population and form a new population; the gene pool is different compared to the o.g.

Homologous Structure

Structures in different species that are similar because of common ancestry.

Analogous Structure

Body parts that share a common function, but not structure

Vestigial Organ

Organ that serves no useful function in an organism

Fossils

Preserved remains of once-living organisms

Embryology

The study of embryos and their development

DNA + Proteins

DNA carries genetic instructions; proteins make up the instructions

Divergent Evolution

The process where two or more related species become increasingly dissimilar over time

Convergent Evolution

Process by which unrelated organisms independently evolve similarities when adapting to similar environments

Coevolution

Process by which two species evolve in response to changes in each other

Producers / Autotrophs

Organisms that produce their own food

Consumers / Heterotrophs

Obtain energy by consuming other organisms

Herbivores

Consumers that eat only plants

Omnivores

Eat both plants and animals

Carnivores

Consumers that eat only animals

Decomposers

Organisms that break down the dead remains of other organisms

Biogeochemical Cycle

Process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another

Biosphere

The part of Earth in which life exists including land, water, and air or atmosphere

Geosphere

The solid part of the earth consisting of the crust and outer mantle

Atmosphere

A thin layer of gases surrounding the Earth

Hydrosphere

All the water at and near the surface of the earth, 97% of which is in oceans

Photosynthesis Equation

6CO2 + 6H2O + light energy = C6H12O6 + 6O2

Cellular Respiration Equation

C6H12O6 + 6O2 = 6CO2 + 6H2O + ATP

Photosynthesis

process by which plants convert light energy, carbon dioxide, and water, into oxygen and glucose

Cellular Respiration

The process by which cells take food (glucose) + oxygen, and convert it into energy (ATP), carbon dioxide, and water.

Aerobic Respiration

Respiration that requires oxygen

Anaerobic Respiration

Respiration that does not require oxygen

Fermentation

Process by which cells release energy in the absence of oxygen

Energy Pyramid

A representation that illustrates how energy flows through an ecosystem's food chains; producers harbor the most energy, and travelling upwards, the amount of available energy decreases.

Hydrologic Cycle

The movement of water through the biosphere; the water cycle

Nitrogen Cycle

The transfer of nitrogen from the atmosphere to the soil, to living organisms, and back to the atmosphere; bacteria are necessary for this cycle

Carbon Cycle

The movement of carbon from the nonliving environment into living things and back

Energy and Matter Movement

In an ecosystem, matter is recycled, while energy flows through

Population

A group of individuals that belong to the same species and live in the same area

Habitat

Place where an organism lives

Niche

The specific role or position of an organism within its ecosystem

Population Growth

The increase in the number of individuals in a population

Exponential Growth

Describes a population that increases rapidly, with its growth rate accelerating as the population size gets larger

Logistic Growth

Describes a population growth pattern where the initial rapid growth slows down, eventually leveling off when the environment's carrying capacity is reached

Carrying Capacity

Largest number of individuals in a population, that an environment can support

Limiting Factor

Environmental elements that restrict a population's size or growth rate

Density Independent (limiting factor)

Environmental conditions that affect a population's size regardless of its population density

Density Dependent (limiting factor)

Environmental influences on a population that change in effect based on the population's density

Competition

The struggle between organisms to survive in a habitat with limited resources

Predation

An interaction in which one organism kills another for food.

Parasitism

A relationship between two organisms of different species where one benefits and the other is harmed

Mutualism

A relationship between two species in which both species benefit

Commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected

Global Warming

A gradual increase in average global temperature

Greenhouse Gases

Gases in the Earth's atmosphere that trap heat near the surface