BIO FINAL EXAM NOTES

Population

A group of organisms of the same species living together in the same geographic area and are breed-able with each other.

Fitness

The relative ability of an organism to reproduce in a particular environment.

MRSA

Methicillin-Resistant Staphylococcus Aureus, an infectious bacterium difficult to treat with antibiotics.

Binary Fission

Process by which bacterial cells asexually reproduce, dividing one parental cell into two daughter cells.

Natural Selection

The process where organisms that are better adapted to their environment survive and reproduce more than those less adapted.

Gene Pool

The collection of alleles in a population.

Microevolution

Small scale evolution resulting in changes in allele frequencies within a population.

Stabilizing Selection

A type of natural selection that favors intermediate variants and acts against extreme phenotypes.

Directional Selection

A form of natural selection in which one extreme phenotype is favored.

Disruptive Selection

A type of natural selection that favors extreme phenotypes over intermediate phenotypes.

Speciation

The process by which new species arise, typically when gene pools become isolated.

Reproductive Isolation

A mechanism that prevents species from interbreeding and producing fertile offspring.

Prezygotic Barriers

Reproductive barriers that prevent mating or fertilization between species.

• Habitat isolation - Location issues

• Temporal Isolation - Differing breeding schedules

• Behavioral Isolation

• Mechanical Isolation

• Gametic Isolation

Postzygotic Barriers

Reproductive barriers that occur after fertilization, affecting hybrid offspring.

• Reduced hybrid viability - Genetic incapabilities not allowing offspring hybrids to survive

• Reduced hybrid fertility - No future generations

• Hybrid breakdown

Founder Effect

A form of genetic drift where a small group from a population establishes a new population.

Bottleneck Effect

A reduction in genetic diversity due to a significant reduction in population size.

Gene Flow

The transfer of alleles from one population to another.

Hardy-Weinberg Equilibrium

A state in which allele and genotype frequencies in a population remain constant from generation to generation.

Inbreeding Depression

A reduction in biological fitness due to mating between closely related individuals.

Keystone Species

A species that has a disproportionately large impact on its environment relative to its abundance.

Trophic Cascade

An ecological phenomenon triggered by the addition or removal of top predators, which results in changes in ecosystem structure and nutrient cycling.

Ecosystem

A biological community of interacting organisms and their physical environment.

Abiotic Factors

Nonliving chemical and physical parts of the environment that affect living organisms.

Biotic Factors

Living components that affect the population of organisms in an ecosystem.

Carnivorous Plants

Plants that obtain some or most of their nutrients from trapping and consuming animals.

Ecological Succession

The process of change in the species structure of an ecological community over time.

Mutualism

A symbiotic relationship where both species benefit.

Parasite

An organism that lives on or in a host organism and causes harm to the host.

Extinction

The dying out of a species; the end of an organism or a group of organisms.

Climate Change

A change in global or regional climate patterns, often attributed to an increase in atmospheric carbon dioxide.

Biodiversity

The variety of life in the world or in a particular habitat or ecosystem.

Population Density

The number of individuals of a particular species per unit area.

Habitat Fragmentation

The process by which a large continuous area of habitat is divided into smaller, isolated patches.

Trophic Level

The hierarchical levels in an ecosystem, comprising producers, primary consumers, secondary consumers, and so on.

Invasive Species

Non-native species that spread widely in a new habitat and cause harm to the environment, economy, or health.

Carrying Capacity

The maximum number of individuals of a particular species that an environment can sustain indefinitely.

Ecological Footprint

A measure of the demand placed on Earth's ecosystems by human activity.

Sustainable Development

Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

Eutrophication

The process by which water bodies become enriched with nutrients, often leading to excessive growth of algae.

Pollination

The process by which pollen is transferred from the male part of a flower to the female part, enabling fertilization.

Endemic Species

Species that are native to and found only within a specific geographic area.

Ecological Niche

The role and position a species has in its environment, including habitat use, resource use, and interactions with other species.

Succession Types

The two main types of ecological succession: primary succession (starts from bare substrate) and secondary succession (follows disturbance).

Carbon Cycle

The series of processes by which carbon compounds are interconverted in the environment.

Heterotrophs

Organisms that cannot produce their own food and must consume other organisms for energy.

Autotrophs

Organisms, primarily plants and algae, that produce their own food through photosynthesis or chemosynthesis.

Primary Producers

Organisms that produce their own food, typically through photosynthesis, forming the base of a food chain.

Primary Consumers

Organisms that eat primary producers; they are herbivores.

Secondary Consumers

Organisms that eat primary consumers; they can be carnivores or omnivores.

Tertiary Consumers

Organisms that eat secondary consumers; they are typically top predators in an ecosystem.

Apex Predator

A predator at the top of the food chain that has no natural predators, playing a critical role in maintaining the structure of the ecosystem.

Genetic Drift

A mechanism of evolution that refers to random changes in the frequency of alleles in a population.

Nonadaptive Mechanisms

Mutation, Gene Flow, and Genetic Drift are considered nonadaptive as they do not enhance the fitness of organisms.

Adaptive Mechanisms

Natural Selection is NOT nonadaptive; it favors traits that improve an organism's fitness and reproductive success.