bio 102 final exam

anecdotal evidence

derived from personal observation and experience

scientific evidence

derived from systematic observation and experimentation

what is the wolf-effect theory?

wolves kept elk numbers at a level that prevented them from gobbling up every aspen or willow tree that poked its head above ground

randomized clinical trial

randomly chosen subjects are used in control and experimental groups

independent variable

the variable that is changed

dependent variable

the variable that is measured in the experiment

correlation

a consistent relationship between two variables

a smaller p-value means?

higher statistically significant

larger sample size means?

statistically significant results

scientific theory

a hypothesis proven after many years of rigor testing

case control studies

observational studies in which people without a disease are compared to controls to identify the cause of the disease

methicillin-resistant Staphylococcus aureus (MRSA)?

infectious bacterium, difficult to treat with antibiotics, killed 10,000 people in the US in 2012

approx. what percent of people in the US have staph?

33%

approx. what percent of the US has a MRSA strain?

2%

how is MRSA contracted?

from person to person through direct or indirect contact; skin to skin, contact sports, used soap, towels, and equipment

why do athletes have increased risk of skin infections?

contact with skin, items, or surfaces that harbor MRSA

ONLY eukaryotes

nucleus, many organelles, cell membrane

ONLY prokaryotes

DNA floating freely in cytoplasm, no organelles, cell wall made of peptidoglycan, a rigid structure enclosing the cell membrane, very high peptidoglycan in Gram positive bacteria

gram-positive bacteria stains what color?

purple

gram-negative bacteria stains what color?

pink

Gram-positive

high amount of peptidoglycan in cell wall retains the gram stain

gram-negative

lipid outer layer of cell wall does not retain the Gram stain

function of antibiotics

interfere with the function of essential bacterial cell structures

how do beta lactams work?

interfere with a bacterium’s ability to synthesize cell walls

binary fission

one parental cell divided into two daughter cells

random mutations can create?

new alleles that cause some bacteria to be resistant to antibiotics

gene transfer can spread?

alleles for antibiotic resistance to other bacteria

population

group of organisms of the same species living together in the same geographic area

an entire population can change (evolve) when some traits are?

favored over others

in the presence of antibiotics, sensitive variants have what type of fitness?

low fitness

in the presence of antibiotics, resistant variants have what type of fitness?

medium fitness

in the presence of antibiotics, highly resistant variants have what type of fitness?

high fitness

evolution

change in allele frequency over time

fitness

organisms ability to survive and reproduce in a particular environment

higher fitness = ?

increased likelihood of alleles being passed to next generation

genotypes determine?

phenotype

environment determines?

success of a phenotype

successful phenotypes becomes?

more common in the population

change in phenotype frequency leads to?

change in genotype frequency which leads to evolution

natural selection

differential survival and reproduction of individuals within a population in response to environment

populations not _____ evolve?

individuals

directional selection

predominant phenotype shifts in a particular direction

stabilizing selection

phenotype of population settles near middle of range

which phenotypes are better suited to the environment than individuals at either extreme in stabilizing selection?

intermediate phenotypes

diversifying selection

phenotype of population is at both extremes of range

high fitness creates?

strong direction selection for antibiotic resistance

how can bacteria resist the effects of antibiotics?

mutations to genes or by acquiring new genes from other bacteria

antibiotic resistance populations of bacteria emerge by?

directional selection in the presence of antibiotics

alleles

different variants of the same gene that determine a particular trait for a characteristic

population genetics

study of all the alleles in a population

what was darwin’s proposition?

all living things descended from common ancestors

what was charles darwin’s book called?

On the Origin of Species

microevolution

genetic change that occurs over small timescale in a population and results in a small change in heritable traits

which type of evolution is considered speciation?

macroevolution

macroevolution

the process by which a new species arises; genetic change that occurs over long time scales resulting in large changes in heritable traits in a population

the population colony of bacteria usually doubles every?

20-30 minutes

urban environments are called?

powerhouses of evolution

extreme conditions in the cities that cause adaptation and evolution more quickly than other places?

pollution, noise, fragmentation of the land, artificial lights causing light pollution

population genetics

study of the genetic makeup of populations and how genetic composition changes

gene pool

total collection of alleles in a population

allele frequency

the relative proportion of an allele in a population

evolution of populations is caused by?

changes in allele frequency over time

nonadaptive evolution

random changes that do not affect fitness for an environment

what 3 factors cause nonadaptive evolution?

mutation, genetic drift, and gene flow

genetic drift?

random change in allele frequencies between generations that occurs purely by chance

genetic drift does what to genetic diversity?

decreases

the smaller the population the ____ the genetic drift

greater founde

founder effect

a type of genetic drift in which a small number of individuals leaves one population and establishes a new one

bottleneck effect

a type of genetic drift that occurs when a large population is suddenly reduced to a small number of individuals

why is the white North African rhino particularly vulnerable to poaching?

it is relatively unaggresisive and lives in herds

gene flow

movement of alleles from one population to another

urbanization can prevent gene flow and lead to?

inbreeding

inbreeding increases the proportions of ______ to ?

homozygous to heterozygous

inbreeding depression

closely related individuals are more likely to share the same alleles

hardy-weinberg equilibrium

used to identify genes that have changed because of evolutionary mechanisms

what is the most frequently used species concept?

the biological species concept

biological species concept

a population of individuals whose members can interbreed and produce fertile offspring; species cannot mate because they are reproductively isolated

ecological isolation

species live in different environments

temporal isolation

species have different mating or fertility time frames

behavioral isolation

species display different mating activities

mechanical isolation

species have incompatible mating organs

gametic isolation

species have incompatible gametes

hybrid inviability

species’ gametes unite but viable offspring cannot form

hybrid infertility

offspring are viable but cannot reproduce

genetic divergence leads to?

reproductive isolation and formation of a new species

speciation

the formation of two species from one original species

allopatric speciation

geographic separation and speciation in a different location

sympatric speciation

speciation in the same geographic location

living organisms are separated by?

phylogenetic distances

paleontologists

scientists who study ancient life by means of the fossil record

fossil

perserved remains or impressions of once-living organisms

fossil record

an assemblage of fossils arranged in order of age, which provides evidence of changes in species over time

Tiktaalik

transition between fish and land-dwelling animal

what is darwin’s theory of evolution?

descent with modification; all living things are related, different species emerged over time due to natural selection

radiometric dating

use of radioactive isotopes as a measure for determining the age of a rock or fossil

relative dating

determining the age of a fossil from its position relative to: layers of rock and fossils of known age

isotopic dating

used to reconstruct the ecology and biogeography of organisms living within the past

half-life

the length of time it takes for one half of the original atom of the radioactive isotope to decay into an atom of a new isotope

what type of animal is the lithographic referred to as?

intermediary; has bird and reptile characteristics

characteristics of Tiktaalik

jointed elbow, wrist, and fingerlike bones