JMU BIO 150 Final Exam

Define biodiversity

the diversity of plant and animal life in a particular habitat (or in the world as a whole)

Define genetic diversity

the total genetic information contained within all individuals of a species, population, or community

Why is genetic diversity important?

provides the raw materials for adaptive change

Define adaptive change

change in response to the environment's "natural selection:

Define species diversity

the diversity of species present in a community

Why is species diversity important?

species have a particular "role" in a system, so the addition or loss of a species may have consequences for the entire system

How is species diversity measures?

-species richness

-species abundance

Define species richness

number of species in a community

Define species abundance

The number of individuals of each species

Define ecosystem diversity

measure of the variety of biotic components in a region along with abiotic components

Why is ecosystem diversity important?

ecosystem functioning is dependent on interacting member organisms with their environment

Define system stability

diverse systems are resilient after and resistant to disturbances

Define ecosystem productivity

diverse systems have higher net primary productivity

Define ecosystem services

direct and indirect benefits that humans derive from organisms and ecosystems

Define existence value

economic value of a system and our willingness to mitigate biodiversity loss

What are provisioning services?

raw materials (food, fuel, fiber, medicine, genetic resources)

What are regulating services?

life support system (climate moderation, soil formation, erosion control, water capture, flood control etc.)

Define ecosystem services

all direct and indirect benefits that humans derive from organisms and ecosystems

What are cultural services?

cultural/intrinsic (aesthetics, recreation, education, spiritual value, and physical/mental health)

What are supporting services?

primary productivity, nutrient cycling, pollination, and biological control

What are the primary threats to biodiversity?

-habitat loss

-climate change

-invasive species

-overexploration

-pollution

What are characteristics of viruses?

-very,very small

-not a cell

-can not reproduce independently

-does not contain ribosomes or generate ATP

What are characteristics of bacteria?

-small but bigger than virus

-single cell

-reproduce independently

-contains chromosomes and generate ATP

What do beta-lactums do?

break down cell wall

What do macrolides do?

affect ribosomes

What does quinolines do?

break down DNA and prevent repair

Define intrinsic resistance

resistance naturally coded and expressed by a bacterial species to a particular antibiotic

Define acquired resistance

genetic change that leads to bacteria becoming resistant to an antibiotic

How did Plato address evolution?

evolved as distinct different groups

How did Aristotle address evolution?

scale (simple -> high)

How did Lamarck address evolution?

organisms change in response over time

How did Darwin and Wallace address evolution?

change through time from a common ancestor

What did Darwin observe?

different species are often similar, with slight variations in theme

Define evolution

change in the genetic composition of a population from one generation to the next

Define pattern

observed evolutionary change

Define process

mechanisms that produce observed patterns of change

Define natural selection

process in which organisms with certain inherited traits are more likely to survive and reproduce than those without the trait

Define adapatation

inherited trait that enhances the fitness of an individual in a given environment

Define biological fitness

the relative survival and reproduction of one variant compared to others in the same population

Where does the variation that natural selection acts on come from?

-sexual reproduction/gene transfer

-random mutation in DNA that provides raw genetic material

Define vertical gene transfer

occurs during reproduction between generations of cells

Define horizontal gene transfer

process in which an organism incorporates genetic materials from another without it being its offspring

Define plasmids

about 20 special genes (found for antibiotics)

Define varation

individuals in a population vary in their traits

Define inheritance

some of the trait differences are inherited from the parents to offspring

Define overproduction

organisms produce more offspring than the environment can support

Define differential reproduction

individuals that are well suited to their environment tend to survive and leave more offspring than other

Define survival and reproduction

it is not random; overtime, favorable traits accumulated

Define Hardy Weinberg Principle

the allele and genotypic frequencies in a population with remain constant from generation to generation in the absence of evolutionary influences

Define of null hypothesis

statement of no change

What are the assumptions of HW-Equilibrium?

1. There can be no difference in the survival and reproduction of individuals

2. Populations may not be added to or subtracted from by migration

3. There can be no mutation

4. The population must be sufficiently large to prevent sampling errors

5. Individuals mate at random

How do you calculate allelic frequencies?

p+q=1

How do you calculate genotypic frequencies?

P^2 + 2pq + q^2 = 1

p = what?

dominate

q = what?

recessive

Define microevolution

small changes in the gene pool of a population over successive generations

Define gene pool

all the genes in a population at a given time

What are the three types of evolutionary mechanisms?

-selection

-genetic drift

-gene flow

Define artificial selection

form of directional selection where given traits are selected for by humans

Define sexual selection

promotion of traits that increase individual's access to reproductive opportunities

Define intersexual selection

male evolves traits to attract females

Define intrasexual selection

competition within genders

Define genetic drift

change in the populations' allelic frequency due to a random event

What size group does genetic drift have a larger effect on?

smaller populations

Define bottleneck effect

reduction in population size due to a disturbance

Define founder effect

individuals from a large population colonize new areas

What are the three modes of natural selection?

-stabilizing selection

-directional

-divergent (disruptive)

Define stabilizing selection

intermediate phenotype have a higher fitness than the extreme varieties

Define directional selection

individuals with one of the extreme phenotype has a higher fitness than intermediate varieties

Define divergent (disruptive) selection

both extreme phenotype are favored at the expense of intermediate varieties

Define balancing selection

occurs when 2 distinctly different polymorphis occur exist in relatively equal frequencies

Define non-random mating

the probability that two individuals in a population will mate is not the same for all possible pairs of individuals

Define inbreeding depression

reduced survival and reproduction due to inbreeding, increasing the likelihood of carrying recessive deleterious alleles

Define gene flow

random genetic exchange of alleles population due to migration

What effect does gene flow have?

homogenizing effect (decreases variation caused by drift

Define speciation

the formation of new and distinct species in the course of evolution

How can species become evolutionary independent?

little gene flow between different species

How can you tell if they are two species?

-they can mate

-the don't look like each other

Define biological species concept

one or more populations whose members interbreed under natural conditions & produce fertile offspring

Why might individuals within a species not mate?

-asexual

-geographic

Define morphological species concept

use visible morphology (do they look different?)

Define ecological species concept

-species can be characterizes by its ecological niche

-two species cannot occupy the same niche in the same location due to competition

-can apply to telling some bacterial species apart

What are the two steps of speciation?

-initial identical populations must have restricted gene flow so they can diverge

-reproductive isolating mechanisms must evolve to maintain these differences

Define macroevolution

evolutionary change above the species level, including the origin of a new group of organisms or a shift in the broad pattern of evolutionary changes over time

How do we identify a species?

groups of actually or potentially interbreeding populations that are reproductivley isolated from other such groups

Define reproductive isolation

cannot produce viable offspring

Define viable

offspring can reproduce

Define speciation

splitting event that creates two or more distinct species from a single ancestral group

What are the three stages of specification?

1. population separation

2. divergence

3. productive isolation preventing gene flow

Define population separation

isolation of gene pool

Define divergence

changes in gene pool (1 or both)

What are the two types of separation of populations?

-allopatric model

-sympatric model

Define allopatric model

separation due to geographic isolation

Define sympatric model

separation due to competition or polylodisism in population

What are the mechanisms of allopatric separation?

-dispersal and colonization

-vicariance

Define dispersal and colonization

-start with one continuous population

-goes to an isolated area (island)

-finishes with one population isolated from the other

Define vicariance

-start with one continuous population

-landscape is changed

-two populations are isolated from one another

When does peripatric speciation occur?

when one of the isolated populations have very few individuals

What causes divergence of populations in sympatric speciation?

-disruptive selection

-polyplodism

Define adaptive radiation

the rapid diversification of a group of organisms into forms filling different ecological niches via sympatry