BIO 141 Midterm 3 Review
Ecosystem
A biological community of interacting organisms and their physical environment.
Bottleneck effect
A change in allele frequency following a dramatic reduction in the size of a population
Genetic drift
A change in the gene pool of a population due to chance
An age pyramid with a broad base that quickly slopes up to a narrow top would be indicative of ____
A developing nation
Sexual selection
A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates.
Biome
A group of ecosystems that share similar climates and typical organisms
Population
A group of individuals that belong to the same species and live in the same area
Community
A group of interdependent organisms inhabiting the same region and interacting with each other
Species
A group of similar organisms that can breed and produce fertile offspring.
Commensalism
A relationship between two organisms in which one organism benefits and the other is unaffected
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
From an evolutionary perspective, behavior can be viewed best as:
A trait that can satisfy the three conditions required for evolution by natural selection.
Monomorphism
All individuals have the same allele for a given gene
The processes of chemical cycling would be studied mainly be ____
An ecosystem ecologist
Limiting factor
Any biotic or abiotic factor that restricts the existence, numbers, reproduction, or distribution of organisms.
Biotic
living
What are the six levels of organization from least inclusive to most inclusive?
species, population, community, ecosystem, biome, biosphere "Some People Can't Easily Buy Balloons"
Darwinian fitness
the ability of an individual to survive and reproduce in its environment
Dimorphism
the instance of polymorphism in which there is a difference of form between two members of a species, as between males and females
Kin selection
the process by which evolution selects for individuals who cooperate with their relatives
What are the three main types of symbiosis?
Commensalism, mutualism, parasitism
Which theorem states that no two species competing for the exact same resources can coexist?
Competitive exclusion principle
___ selection favors organisms that have character values at one extreme of the phenotypic distribution
Directional
What is the name of the theoretical maximum rate of population growth?
Exponential
Assume that you carry an allele R, that cause you to help individuals to whom you are not related. This help increases their fitness and decreases yours. The frequency of allele R may still increase in the population:
If individuals you help are likely to return the favor and help you at some point in the future.
A sudden natural catastrophe resulting in massive die-offs would be categorized as a density-_____ factor
Independent
Why or why is it not accurate to say that individuals evolve?
It is not accurate because individuals do not change over time in a way that can be passed on to the next generation.
Carrying capacity
Largest number of individuals of a population that a environment can support
An ecosystem is a collection of all the ___ in a given area.
Living and nonliving things
Which of the following is the best way to distinguish male from female?
Males produce motile gametes
There have been several mass extinctions in the planet's history, but the current mass extinction is different. What is causing the current mass extinction?
Man's direct activities
Gene flow
Movement of alleles into or out of a population due to the migration of individuals to or from the population
What is the original source of variation?
Mutation
Difference between natural selection and evolution
Natural selection is a process by which organisms better adapted to their environment tend to survive and produce more offspring, while evolution is the change in the heritable characteristics of biological populations over successive generations.
Stabilizing selection
Natural selection that favors intermediate variants by acting against extreme phenotypes
Abiotic
Non-living
Biosphere
Part of Earth in which life exists including land, water, and air or atmosphere
What is it called when we have one female that mates with many males?
Polyandry
What is it called when we have one male that mates with many females?
Polygyny
What is the smallest unit that can evolve?
Population
Hybrid weakness. Pre or post - zygotic?
Postzygotic. Offspring of two species may be unfit, or they may be sterile
There are little birds that spend a great deal of time on the back of a rhinoceros and eat the blood sucking ticks out of the rhino's ears. The bird-tick relationship is an example of ____
Predator-prey
Behavioral isolation? Pre or post - zygotic?
Prezygotic. Form of reproductive isolation in which two populations have differences in courtship rituals or other types of behavior that prevent them from interbreeding
Mating time differences. Pre or post - zygotic?
Prezygotic. Many species are able to reproduce only at specific times
Mechanical incompatibility. Pre or post - zygotic?
Prezygotic. Members of different species often cannot mate because their anatomies are incompatible
Habitat isolation. Pre or post - zygotic?
Prezygotic. Populations live in different habitats and do not meet
Gametic incompatibility. Pre or post - zygotic?
Prezygotic. Sperm from one species cannot fertilize eggs of another species
What are the three conditions required for evolution to occur?
Resources in the environment must be limited. Traits must be heritable. Individuals within a population must vary in their ability to compete for resources.
Resource partitioning
The division of environmental resources by coexisting species such that the niche of each species differs by one or more significant factors from the niches of all coexisting species
"Ecology" is best defined as the study of ____
The interactions between living organisms and their environments.
Despite an abundance of habitat, why will it be difficult for the human species to recover (from a single family)?
The reduced genetic diversity will make it difficult for the population to adapt to new diseases or other environmental changes.
Sexual dimorphism refers to:
The situation in which males and females differ physically and/or behaviorally.
Why are mules considered to be a "weak hybrid"?
They are sterile
Altruistic behavior
action in which an organism helps another at its own expense
Reciprocal altruism
behavior that benefits another with the expectation that those benefits will be returned in the future
An ecosystem contains
both the living organisms and the abiotic components of the environment
Founder effect
change in allele frequencies as a result of the migration of a small subgroup of a population
Which of the following is an example of a biotic factor? Energy Temperature Bacteria Nutrients
Bacteria
What are the six main reproductive barriers?
Behavioral isolation Habitat isolation Gametic incompatibility Mating time differences Mechanical incompatibility Hybrid weakness
What are the five main mechanisms of evolution?
Genetic drift Gene flow Bottleneck effect Founder effect Sexual selection
Logistic growth
Growth pattern in which a population's growth rate slows or stops following a period of exponential growth
What are five main causes of biodiversity loss?
Habitat destruction Overharvesting Invasive species Pollution Global climate change