Bio116 Lecture Exam 4 Review Flashcards

These vocabulary flashcards cover major themes from Ecology, Population and Community Dynamics, and Microbiology based on the Bio116 Exam 4 Review Sheet.

Ecology

The study of the interactions between organisms and their environment.

Biotic factors

The living components of an environment that influence the distribution and abundance of organisms.

Abiotic factors

The non-living physical and chemical components of an environment, such as temperature, light, water, and nutrients.

Climate

The long-term prevailing weather conditions in a given area, determined by factors like temperature, precipitation, sunlight, and wind.

Coriolis Effect

The deflection of prevailing wind currents due to the Earth's rotation; it functions to deflect winds in the northern and southern hemispheres.

Windward side

The side of a mountain where rising air cools and releases moisture as rain or snow.

Leeward side

The rain shadow side of a mountain where cool, dry air descends, often creating desert-like conditions.

Greenhouse gasses

Atmospheric gases that function to trap heat, contributing to current global climate change.

Northern Coniferous Forest (Taiga)

The largest terrestrial biome on Earth, characterized by cone-bearing trees.

Photic zone

The upper layer of an aquatic biome where there is sufficient light for photosynthesis.

Aphotic zone

The lower layer of an aquatic biome where little light penetrates.

Benthic zone

The bottom surface of an aquatic biome, consisting of organic and inorganic sediments and occupied by communities of organisms called benthos.

Turnover

The seasonal process in temperate bodies of water where oxygenated surface water moves to the bottom and nutrient-rich bottom water moves to the surface.

Population

A group of individuals of a single species living in the same general area.

Demography

The study of vital statistics of a population, such as birth rates and death rates, and how they change over time.

Survivorship curve

A graphic method of representing the proportion or numbers of individuals in a cohort still alive at each age.

Exponential population growth

Population increase under ideal conditions with abundant resources, resulting in a J-shaped growth curve.

Intrinsic rate of increase ($r$)

The per capita rate at which an exponentially growing population increases in size at each instant in time.

Logistic population growth

A model of population growth where the per capita rate of increase approaches zero as the population size nears the carrying capacity, resulting in an S-shaped curve.

Carrying capacity ($K$)

The maximum population size that a particular environment can sustain.

Semelparity

A life history strategy also known as "big-bang reproduction," where an organism produces all its offspring in a single event.

Iteroparity

A life history strategy characterized by repeated reproduction over many years.

$r$-selected species

Species that tend to maximize reproductive success in uncrowded, unpredictable environments.

$K$-selected species

Species that are sensitive to population density and are favored at high densities near the carrying capacity.

Community

A group of populations of different species in an area living close enough for potential interaction.

Interspecific interactions

Relationships between individuals of different species in a community, classified by their positive ($+$, negative ($-$), or neutral effects.

Commensalism

A positive/neutral ($+/0$) interaction in which one species benefits while the other is neither helped nor harmed.

Mutualism

A positive/positive ($+/+$) interspecific interaction that benefits both species.

Amensalism

An interaction where one species is harmed ($-$) and the other is unaffected ($0$).

Parasitism

A positive/negative ($+/-$) interaction in which one organism, the parasite, derives nourishment from another organism, the host, which is harmed.

Competitive exclusion

The principle that two species competing for the same limiting resources cannot coexist in the same place.

Resource partitioning

The differentiation of niches that enables similar species to coexist in a community.

Species richness

The total number of different species in a community.

Trophic structure

The feeding relationships between organisms in a community, often represented by food chains or food webs.

Bacteriophage

A virus that infects and replicates within bacteria.

Lytic cycle

A viral reproductive cycle that culminates in the death of the host cell by lysing and releasing new phages.

Lysogenic cycle

A viral reproductive cycle in which the viral genome becomes incorporated into the bacterial host chromosome as a prophage and does not destroy the host.

Binary fission

A method of asexual reproduction in prokaryotes by which a cell divides into two identical cells.

Transduction

A type of horizontal gene transfer where phages carry prokaryotic genes from one host cell to another.

Transformation

A process of horizontal gene transfer in which a prokaryotic cell takes up foreign DNA from its surrounding environment.

Conjugation

The direct transfer of DNA between two prokaryotic cells that are temporarily joined.

Obligate aerobes

Organisms that must use oxygen for cellular respiration and cannot grow without it.

Obligate anaerobes

Organisms that are poisoned by oxygen and use fermentation or anaerobic respiration.

Halophiles

Members of the domain Archaea that live in highly saline environments.

Thermophiles

Members of the domain Archaea that thrive in very hot environments.

Methanogens

Archaeans that release methane as a byproduct of their unique ways of obtaining energy.

Epidemic

A widespread occurrence of an infectious disease in a community at a particular time.

Pandemic

A global epidemic of an infectious disease.