Principles of Biology Final Examination Review

Vocabulary flashcards covering core concepts of evolution, natural selection, ecology, biomes, and biodiversity conservation based on the lecture notes.

Natural Selection

The process where individuals with certain traits are more likely to survive and reproduce than individuals without those traits, driven by environmental conditions.

Gene pool

Consists of all copies of every type of allele at every locus in all members of the population.

Microevolution

The change in allele frequencies within a population over generations, resulting in small evolutionary changes within a species.

Genetic drift

A random change in allele frequencies in a population due to chance events rather than natural selection, occurring most prominently in small populations.

Mutation

A change in the genetic information encoded in the nucleotide sequence of DNA, serving as the ultimate source of genetic variation.

Genetic Variation

The unique genome of each person or organism which is reflected in phenotype variation.

Gene Flow

The transfer of alleles between populations through the movement and reproduction of individuals, which increases genetic variation and reduces differences between populations.

Speciation

A process that results in one species splitting into two or more descendant species.

Transitional features

Traits in a fossil species that are intermediate between ancestral and derived species.

Fitness trade-off

A compromise between traits in terms of how those traits perform in the environment, resulting from selection acting on many traits simultaneously.

Vestigial traits

Structures or features that once had an important function in an organism’s ancestors but now have little or no function in the current organism.

Homology

A similarity that exists in species descended from a common ancestor, studied at genetic, developmental, and structural levels.

Genetic homology

A similarity in the DNA nucleotide sequences, RNA nucleotide sequences, or amino acid sequences among different species.

Developmental homology

Similarities seen in the embryos of different species, such as gill pouches and tails found in chickens, humans, and cats.

Structural homology

A similarity in adult morphology, such as the common structural plan in the limb bones of most vertebrates.

Biological fitness

The ability of an individual to produce surviving, fertile offspring relative to that ability in other individuals in the population.

Selection

Differential reproduction that occurs as a result of heritable variation.

Adaptation

A heritable trait that increases an individual’s fitness in a particular environment relative to individuals lacking that trait.

Acclimatization

A change in an individual’s phenotype in response to environmental changes where the genotype remains fixed and changes are not passed to offspring.

Bottleneck effect

A type of genetic drift that occurs when a population is suddenly reduced in size.

Founder effect

A type of genetic drift that occurs when a small group starts a new population.

Ecology

The study of how organisms interact with their environment.

Community

Different species living and interacting together in the same area.

Ecosystem

The combination of the living community and the nonliving (abiotic) factors such as water, soil, sunlight, and climate.

Biosphere

The global sum of all life on Earth.

Biotic factors

The living components of an environment.

Abiotic factors

The nonliving components of an environment, such as temperature, water, energy sources, and inorganic nutrients.

Biome

A large ecological region defined by its climate and the specific types of plants and animals that live there.

Pelagic realm

The open water region of the ocean where phytoplankton, fish, and zooplankton live.

Benthic realm

The seafloor or bottom of the ocean, inhabited by organisms like worms, crabs, and bottom feeders.

Photic zone

The depth of water where sunlight reaches, allowing for photosynthesis to occur.

Aphotic zone

The depth of water where there is no sunlight and no photosynthesis, requiring organisms to eat others or use chemical energy.

Tropical forests

Biomes occurring in equatorial areas with warm temperatures, $11-12$ hour days year-round, and variable rainfall.

Savannas

Warm year-round biomes with $30-50\,cm$ annual rainfall, dominated by grasses, scattered trees, and insect herbivores.

Deserts

The driest of all terrestrial biomes, characterized by low and unpredictable rainfall and the potential for extreme heat or cold.

Chaparral

A biome characterized by dense, spiny shrubs with tough evergreen leaves, adapted to periodic fires, mild rainy winters, and hot dry summers.

Tundra

A treeless Arctic biome between the taiga and polar ice, characterized by permafrost and low precipitation.

Temperate grasslands

Mostly treeless biomes found in regions with cold winters and $25-75\,cm$ of annual precipitation with periodic droughts.

Taiga

A cold, forested biome in the northern hemisphere characterized by long winters, short summers, and coniferous trees.

Exotic species

A non-native species that is introduced into a new area.

Invasive species

An exotic species that spreads rapidly and eliminates native species, disrupting ecosystems and reducing biodiversity.

Biodiversity

The variety of life, including species, genes, and ecosystems.

Genetic diversity

The variation of alleles within a population, measured by the number of different alleles and the level of heterozygosity.

Species richness

A count of the number of different species present in a defined region.

Species diversity

A weighted measure that incorporates both species richness and evenness (the relative abundance of each species).

Ecosystem function

The sum of biological and chemical processes characteristic of an ecosystem, including primary production, nitrogen cycling, and decomposition.

Endangered species

A species whose numbers have decreased so drastically that it is almost certain to go extinct without effective conservation.

Overexploitation

Any unsustainable removal of organisms from the natural environment for human use, such as overharvesting marine species or overhunting for bushmeat.

Resistance

A measure of how much a community is affected by a disturbance.

Resilience

A measure of how quickly a community recovers following a disturbance.

Biomagnification

The process by which toxins increase in concentration as they move up the food chain from small organisms to large predators.