Bio: Ch 8, 12 Flashcards
immune system can be divided into
innate and adaptive immunity
innate immunity
aka nonspecific immunity
always active against infection but
cannot target a specific invader and cannot maintain immunologic memory
adaptive immunity
aka specific immunity
target specific invader and can maintain immunological memory
takes time to activate
immune cells come from
bone marrow
sites where immune responses can be mounted
and in which b cells are activated
spleen and lymph nodes
site of t cell maturation
thymus
thymus
site of t cell maturation
gut-associated lymphoid tissue (GALT)
includes tonsils and adenoids
spleen
location of blood storage and activation of b cells
recycling center for red blood cells
filter of blood and lymph for immune system
B-cells turn into ___ to…
plasma cells to produce antibodies as part of adaptive immunity
agents of cell mediated immunity
t cells
monocytes
agranulocytes
phagocytic cells in blood stream
monocytes become
macrophages
macrophages in CNS are called
microglia
macrophages in skin are called
langerhans cells
macrophages in bone are called
osteoclasts
specific immune system can be divided into
humoral immunity and cell mediated immunity
humoral immunity
type of specific immunity
driven by B cells and antibodies
cell mediated immunity
type of specific immunity
driven by t cells
innate defenses
noncellular and cellular
- noncellular
- skin
- mucus
- lysozyme
- stomach
- complement system
- interferons
- cellular
- macrophages (MHC, cytokines)
- dendritic cells
- natural killer cells
- granulocytes
- neutrophils, eosinophils, basophils
immune system
skin
innate immune system
physical barrier
secretes antimicrobial compounds such as defensins
mucus
innate immune system
traps pathogens
lysozyme
innate immune system
in tears and saliva
antibacterial compound
immune system
stomach
innate immune system
produces acid, killing most pathogens
colonization of gut helps prevent overgrowth by pathogenic bacteria through competition
complement system
innate immune system
punch holes in cell walls of bacteria, making them osmotically unstable
interferons
innate immune system
given off by virally infected cells
help prevent viral replication and dispersion to nearby cells
macrophages
innate immune system
ingest pathogens and present them on MHC molecules
secrete cytokines
MHC class I (MHC-I)
innate immune system
present in all nucleated cells
displays endogenous antigen to cytotoxic t cells (CD8+ cells)
endogenous antigen
proteins from within the cell
MHC class II (MHC-II)
innate immune system
present in professional antigen-presenting cells (macrophages, dendritic cells, some b cells, certain activated epithelial cells)
displays exogenous antigen to helper t cells (CD4+ cells)
exogenous antigen
proteins from outside the cell
dendritic cells
innate immune system
antigen presenting cells in skin
natural killer cells
innate immune system
attack cells not presenting MHC molecules, including virally infected cells and cancer cells –> induce apoptosis
granulocytes
include
innate immune system
include neutrophils, eosinophils, and basophils
neutrophils
innate immune system
ingest bacteria, particularly opsonized bacteria (those marked with antibodies)}
can follow bacteria using chemotaxis
eosinophils
innate immune system
used in allergic reactions and invasive parasitic infections
release histamine
basophils
innate immune system
used in allergic reactions
release histamine
mast cells
innate immune system
cells found in skin
release histamine
opsonnized
marked with antibody from b cell
antibodies
target particular antigen
antibody structure
contain two heavy chains and two light chains
have a constant region and variable region
tip = antigen binding region
what happens when antibodies are activated?
humoral immunity
- activated by b cell
- antigen binding region undergoes hypermutation to improve the specificity of antibody produced
- cells may be given signals to switch isotypes of antibody
cell surface antibodies
humoral immunity
can activate immune cells or mediate allergic reactions
memory b cells
humoral immunity
wait for second exposure to a pathogen and can mount a more rapid and vigorous response (secondary response)
t cells under goe maturation in the ___ through…
thymus
positive selection and negative selection
positive selection
only selecting for t cells that can react to antigen presented on MHC
negative selection
causing apoptosis in self reactive t cells
helper t-cells (CD4+)
cell mediated (cytotoxic) immunity
- respond to antigen on MHC-II and coordinate rest of immune system
- secrete lymphokines to activate other arms
- Th1 cells
- Th2 cells
Th1 cells
cell mediated (cytotoxic) immunity
secrete interferon gamma, which activates macrophages
Th2 cells
cell mediated (cytotoxic) immunity
activate B cells, primarily in parasitic infections
cytotoxic t-cell (CD8+)
cell mediated (cytotoxic) immunity
repond to antigen on MHC-I and kill virally infected cells
suppressor (regulatory) t cells
cell mediated (cytotoxic) immunity
tone down the immune response after an infection
promote self tolerance
memory T cells
cell mediated (cytotoxic) immunity
remember and can mount faster immune response
autoimmune conditions
self antigen is identified as foreign
immune system attacks the body’s own cells
allergic reaction
nonthreatening exposures incite an inflammatory resposne
active immunity
activation of B cells that produce antibodies to an antigen
immunization
induces active immunity prior to exposure to a particular pathogen
passive immunity
transfer of antibodies to an individual
lymphatic system
circulatory system that consists of one way vessels with intermittent lymph nodes
- equalizes fluid distribution
- transports fats and fat soluble compounds in chylomicrons
- provides sites for mounting immune response
lymphatic system connects to cardiovascular system via
thoracic duct in posterior chest
HIV
loss of helper t cells
prevents immune system from mounting an adequate response to infection
degranulation
when antigen binds to antibodies on surface of mast cell and exocytosis of granule contents happens
primary response
initial activation of memory cells
can take several days
lymphokines
recruit other immmune cells and increase their activity
self tolerance
when suppressor t cells turn off self reactive lymphocytes to prevent autoimmune diseases
what are the 3 main effects circulating antibodies can have on a pathogen
- mark a pathogen for destruction by phagocytic cells
- cause agglutination of pathogen into insoluble complexes that can be taken up by phagocytic cells
- neutralize pathogen by preventing it from invading tissues
how do antibodies become specific for a given antigen?
- b cells that mature in bone marrow have some specificity
- antibodies that can respond to a given antigen undergo hypermutation
- only those b cells have the highest affinity for the antigen survive and proliferate, increasing the specificity for the antigen over time
a t cell appropriately passes through positive selection, but then inappropriately passes through negative selection. what will this t cell be reactive toward?
reactive to self antigens
True or False? The lymphatic vessels are special in that they create a closed loop.
False. The lymphatic vessels DO NOT create a closed loop. It is connected to the systemic circulatory system.
As we move from an oxygenated capillary to the deoxygenated capillary, is there an increase or decrease in pressure?
There is a decrease in pressure.
Do blood vessels or lymph have a higher percentage of protein? Why is this important?
Blood vessels. This is because so much fluid gets out from blood vessels, making lymph very diluted. Having a higher concentration of protein in the blood makes it more osmotically active, pulling water back into the blood stream, preventing edema (swelling).
As we move down a capillary, the blood is more osmotically active. Does this cause fluid to enter or leave the capillary?
Because there is a higher osmotic pressure inside the capillary, this causes fluid to re-enter the capillary.
Which of the following are antibacterial enzymes found in the skin?
(A) Sweat
(B) Defensins
(C) Integrins
(D) Langerhans
(B) Defensins
Defensins are antibacterial enzymes found in the skin. Sweat is not an enzyme, but it does have microbial properties!
Which acts faster? Non-specific/Innate Immunity or Adaptive/Specific Immunity?
Innate Immunity acts faster as Adaptive Immunity requires time to recognize and prepare defenses against invaders. Think about how B and T Cells need to replicate and divide in order to prepare for a certain invader.
True or false? The main actors of the specific immune system are lymphocytes.
True. The main actors of the specific immune system are lymphocytes such as B and T Cells.
Which of the following are different types of phagocytes in the body?
I. Neutrophils
II. Macrophages
III. Dendritic Cells
(A) III only
(B) III and I only
(C) I and II only
(D) I, II, and III
(D) I, II, and III.
Neutrophils, Macrophages and Dendritic Cells are all different types of phagocytes found in the body.
True or false? Macrophages are the fast and abundant phagocytes.
False. Neutrophils are the fast and abundant type of phagocytes.
Macrophages are the the most versatile but not as abundant as neutrophils.
CRB Compare the Complement System and Interferons, which are two other parts of the nonspecific Immune Response.
The complement system is based off many proteins in the blood, and will punch holes in bacterial cell membranes in the blood.
Interferons are proteins that prevent viral replication and dispersion, and will be produced by cells that have been already infected by viruses.
True or false? The humoral response of the B-lymphocytes comes into play if the cell has been colonized by a virus or bacteria
False. Humoral response comes into the picture if the bacterial/virus cells are floating around in the humoral fluid and haven’t colonized a cell yet.
B Cells have receptors presented on their membranes that recognize the proteins of invaders. We might think of these receptors as:
(A) Membrane-bound Antigens
(B) Membrane-bound Antibodies
(C) Membrane-bound MHC I
(D) Membrane-bound MHC II
(B) Membrane-bound Antibodies
Each B-lymphocytes have membrane-bound antibodies (aka Immunoglobulins) on their surfaces. Antigens refer to the proteins that are recognized by antibodies.
Antibodies have various mechanisms of action, including Opsonization, Neutralization, and Agglutination. Describe each of these three mechanisms.
Opsonization - tags pathogens for phagocytosis by other white blood cells.
Neutralization - masks dangerous parts of the pathogen, making them no longer pathogenic.
Agglutination - Multiple pathogens are bound up together, making them easier for digestion/phagocytosis.
Which of the following are examples of Professional (MHC II) Antigen Presenting Cells (APCs)?
I. Macrophages
II. Basophils
III. T Cells
(A) I Only
(B) II Only
(C) I and II Only
(D) I and III Only
(A) I Only
Examples of Antigen Presenting Cells (APCs) include Macrophages, Dendtritic Cells and B Cells.
What is the primary difference between the role of B Cells vs. T Cells?
B Cells produce antibodies.
T Cells recognize and destroy invaders and infected cells.
When a pathogen binds to a receptor on a B-Cell, the B-Cell will form both Memory B Cells and Effector B Cells. What is the difference between these two B Cell types?
Memory B Cells are basically copies of the original B Cell. Their purpose is to recognize future invaders of the same type hence the name “memory”.
Effector B Cells are Antibody producing “factories” with the sole purpose of producing tons of antibodies.
There are two major types of T Cells: Helper T Cells (Th) and Cytotoxic T Cells (Tc). What is the difference between these two?
Cytotoxic T Cells will recognize cells that are infiltrated by an invader and destroy those infected cells.
Helper T Cells will recognize cells that are presenting an antigen via MHC II. Upon binding they will divide into Memory and Effector Th Cells.
Which of the following is not an effect that Antibodies can have on pathogens?
(A) Binding to a specific antigen on the pathogen and attract other leukocytes.
(B) Bind and cause Degranulation, where the granules in the cell undergo exocytosis.
(C) Bind and cause pathogens to Agglutinate, or clump together, so they can be phagocytosed.
(D) Block the ability of pathogens to invade tissues.
(B) Bind and cause Degranulation, where the granules in the cell undergo exocytosis.
Antibodies actually cause Degranulation in Mast Cells, which leads to the mass release of Histamine and inflammation.
Which of the following terms best describes how B cells can change the type of antibody they produce (between IgM, IgG, etc.)?
(A) Clonal Selection
(B) Natural Selection
(C) Isotope Switching
(D) Isotype Switching
(D) Isotype Switching
Isotype Switching is when B cells can change the type of Antibody they produce.
True or False. B Cell receptors can bind both directly to invaders or to MHC complexes that are presenting part of that invader.
False. B Cell receptors do not bind to MHCs.
What happens if a bacteria gets into your bone marrow and binds to a B Cell?
The B Cells that recognize that antigen will be destroyed, leaving you susceptible to infection!
How do Autoimmune diseases relate to these ideas?
When you have B or T Cells that recognize self-antigens, that is known as an Autoimmune Disease.
What is the function of a Neutrophil?
Neutrophils function by phagocytosing invaders and then dying. They are like suicide bombers. After they die they make up what we call “pus”.
chromosome
contain genes in linear sequences
alleles
alternative forms of genes
dominant allele
requires only one copy to be expressed
recessive allele
requires two copies to be expressed
genotype
combination of alleles one has at a given genetic locus
homozygous
having two of the same allele
heterozygous
having two different alleles
hemizygous
having only one allele
(ex male sex chromosomes)
phenotype
observable manifestation of a genotype
complete dominance
effect of one allele completely masks the effect of another
codominance
has more than one dominant allele
incomplete dominance
has no dominant alleles
heterozygotes express a phenotype that is intermediate between the two homozygous genotypes
penetrance
proportion of a population with a given genotype who express the phenotype
expressivity
the different manifestations of the same genotype across the population
mendel’s first law
of segregation
an organism has two alleles for each gene, which segregate during meiosis, resulting in gametes carrying only one allele for a trait
- genes exist in alternative forms (allele)
- an organsim has two alleles for each gene, one inherited from each parent
- two alleles segregate during meiosis
- full dominance
mendel’s second law
of independent assortment
inheritance of one allele does not influence the probability of inheriting an allele for a different trait
Griffith experiment
demonstrated transforming principle
converting nonvirulent live bacteria into virulent bacteria by exposure to heat killed virulent bacteria
injected different live/virulent strains of pneumonia into mice to see if they died
avery-maclead-mccarty experiment
demonstrated that DNA is the genetic material
bc degradation of DNA led to a cessation of bacterial transformation
hershey-chase experiment
demonstrated that DNA is genetic material
only radiolabeled DNA could be found in bacteriophage-infected bacteria
locus
location on a specific chromosome
if expressivity is constant…
all individuals with a given genotype express the same phenotype
if expressivity is variable…
individuals with the same genotype may have different phenotypes
transforming principle
live nonvirulent bacteria acquired the ability to form smooth capsules from dead virulent bacteria
which phase of meiosis does mendel’s first law most closely correlate?
segregation
anaphase I of meiosis
which phase of meiosis does mendel’s second law most closely correlate?
of independent assortment
prophase I of meiosis
gene pool
all of the alleles in a given population
mutations
changes in the DNA sequence
point mutation
substituting of one nucleotide for another
frameshift mutation
moving the three letter transcriptional reading frame
silent mutation
has no effect on the protein
missense mutation
substitution of one amino acid for another
nonsense mutation
substitution of stop codon for an amino acid
insertions and deletions result in
shift in reading frame
deletion mutation
large segment of DNA is lost
duplication mutation
segment of DNA is copied multiple times
inversion mutation
segment of DNA is reversed
insertion mutation
segment of DNA is moved from one chromosome to another
translocation mutation
segment of DNA is swapped with a segment of DNA from another chromosome
genetic leakage
flow of genes between species through hybrid offspring
genetic drift
occurs when composition of gene pool changes as a result of chance
founder effect
extreme case of genetic drift in which small population finds itself in reproductive isolation from other populations
results from bottlenecks that suddenly isolate a small population, leading to inbreeding and increased prevalence of certain homozygous genotypes
codons
3 letter sequences in DNA
inbreeding depression
loss of genetic variation that cuases reduced fitness of the population
outbreeding/outcrossing
introduction of unrelated individuals into a breeding group
monohybrid
cross in which only one trait is being studied
parent generation
P
individuals being crossed
filial generation
F
offspring of the parents that are being crossed
dihybrid cross
studying two genes
punnet ratio
2 heterozygotes
1:2:1
PP:Pp:pp
test cross
used to determine unknown genotype
punnet ratio
dihybrid cross - 2 plants that are heterozygous for both traits
9:3:3:1
recombination frequency
θ
likelihood of two alleles being separating during crossing over in meiosis
genetic maps
can be made using recombination frequency as scale
hardy-weinberg principle
if a population meets certain criteria (aimed at a lack of evolution), then the allele frequencies will remain constant
allele frequency
how often an allele appears in a population
5 criteria for hardy weinberg equilibirum
- population is very large (no genetic drift)
- no mutations that affect gene pool
- mating between individuals is random (no sexual selection)
- no migration of individuals into or out of the population
- genes in population are all equally successful at being reproduced
hardy weinberg eqs
p + q = 1
p2 + 2pq +q2 = 1
p = freq of dominant allele
q = freq of recessive allele
natural selection
chance variations exist between individuals
advantageous variations afford the most opportunities for reproductive success
modern synthesis model
neo darwinism
accounts for mutation and recombination as mechanisms of variation
considers differential reproduction to be the mechanism for reproductive success
inclusive fitness
considers an organism’s success to be based on the number of offspring, success in supporting offspring, and the ability of the offspring to then support others
survival of offspring or relatives ensures appearance of genes in subsequent generations
punctuated equilibrium
considers evolution to be a very slow process with intermittent rapid bursts of evolutionary activity
stabilizing selection
keeps phenotypes in a narrow range, excluding extremes
directional selection
moves average phenotype toward one extreme
disruptive selection
moves the population toward two different phenotypes at the extremes
can lead to speciation
adaptive radiation
rapid emergence of multiple species from a common ancestor, each of which occupies its own ecological niche
species
largest group of organisms capable of breeding to form fertile offspring
species are reproductively isolated from each other by
pre or post zygotic mechanisms
divergent evolution
occurs when two species sharing a common ancestor become more different
parallel evolution
occurs when two species not sharing a recent ancestor evolve to become more similar due to analogous selection pressures
convergent evolution
occurs when two species not sharing a recent ancestor evolve to become more similar due to analogous selection pressures
molecular clock model
degree of difference in the genome between two species is related to the amount of time since the two species broke off from a common ancestor
fitness
related to relative genetic contribution of indivdiual to the next generation
polymorphisms
naturally occurring differences in form between members of the same population
niche
specific environment, including habitat, available resources, and predators, for which a species is specifically adapted
prezygotic mechanisms
prevent formation of zygote completely
includes: temporal isolation, ecological isolation, behavioral isolation, reproductive isolation, gametic isolation
postzygotic mechanisms
allow for gamete fusion but yield either nonviable or sterile offspring
includes: hybrid inviability, hybrid sterility, hybrid breakdown
temporal isolation
breeding at different times
behavioral isolation
lack of attraction between members due to differences in pheromones, courtship displays, etc)
reproductive isolation
incompatible reproductive anatomy
gametic isolation
intercourse can occur, but fertilization cannot
hybrid inviability
formation of a zygote that cannot develop to term
hybrid sterility
forming hybrid offspring that cannot reproduce
hybrid breakdown
forming first generation hybrid offspring that are viable and fertile, but second gen hybrid offspring are inviable and infertile
Mutations are only a serious issue if they occur on the level of:
(A) DNA
(B) mRNA
(C) tRNA
(D) Protein
(A) DNA
A mutation in DNA will result in ALL future proteins being mutated.
DNA mutations may be inherited or they may occur spontaneously. Spontaneous mutations may result from:
I. DNA replication errors.
II. DNA transcription errors.
III. Environmental factors.
(A) I Only
(B) I and II Only
(C) I and III Only
(D) I, II, and III
(C) I and III Only
Spontaneous mutations may result from:
(1) DNA replication errors.
(2) Completely random events.
(3) Environmental factors.
The bottom part of Chromosome 7 switches places with the top part of Chromosome 7. This is an example of a(n):
(A) Inversion
(B) Translocation
(C) Insertion
(D) Deletion
(A) Inversion
An Inversion is a mutation in which two genes of the same Chromosome switch places.
True or false? Crossing over occurs at Tetrads, when there are two sister chromatids attached at by a Centromere (X in appearance).
False. Crossing over occurs at Tetrads, where the homologous chromosomes, each with two sister chromatids attached by Centromeres, are close enough to exchange genetic material (XX in appearance).
Compare the term Allele with the term Gene. Give an example.
A Gene is a portion of DNA that results in a certain trait.
An Allele is a version of a gene.
For instance, you may have a gene for hair color. The three alleles for this gene might be brown, black, or blonde hair.
A cross between a blue bird and a white bird produces only offspring that are light blue (they only have light blue pigments). The color of birds is determined by just two alleles. What are the genotypes of the parent birds in the original cross? Is this an example of incomplete dominance or codominance?
Since the parents produced offspring that are only light blue we must be dealing with incomplete dominance, thus the genotype of the blue bird parent is homozygous blue (BB) and the white bird parent is homozygous white (WW).
Which of the following are forms of Genetic Drift?
I. The Bottleneck Effect
II. The Founder’s Effect
III. Outbreeding
(A) I only
(B) I and II only
(C) II and III only
(D) I, II and III
(B) I and II only
The Bottleneck Effect and Founder’s Effect are both forms of Genetic Drift.
CRB Compare the Bottleneck effect and the Founder’s Effect.
The Bottleneck Effect is whenever a population is drastically reduced, which typically decreases genetic variance. This can occur from a variety of natural disasters.
The Founder’s Effect is a subtype of the Bottleneck Effect, where a small subset of a population will move and find itself in reproductive isolation, again decreasing genetic variance.
p² refers to what?
2pq refers to what?
q² refers to what?
p² refers to the frequency of AA in a given population.
2pq refers to the frequency of Aa in a given population.
q² refers to the frequency of aa in a given population.
What was the conclusion of the Avery-MacLeod-McCarty experiment?
The Avery-MacLeod-McCarty experiment determined that the inheritable disease was passed along by DNA and only DNA, indicating it is the molecule of heritability.
What are autosomal chromosomes?
Autosomal chromosomes are the 22 pairs of homologous chromosomes found similarly in both males and females.
True or false? Autosomal Dominant or Autosomal Recessive genes should have no preference for either sex.
True. Autosomal Dominant or Autosomal Recessive genes should have no preference for either sex.
Crossing Over is the process by which:
I. Genetic Information is transferred from one Homologous Chromosome to another.
II. DNA physically moves from one Homologous Chromosome to the another.
III. Genetic Recombination occurs.
(A) I Only
(B) I and III Only
(C) II and III Only
(D) I, II, and III
(D) I, II, and III
Crossing Over (aka Genetic Recombination) is the process by which Genetic Information is transferred from one Homologous Chromosome to another as DNA physically moves from one Homologous Chromosome to the another.
Which of the following principles was NOT part of Darwin’s original theory of evolution by natural selection?
(A) Evolution is a gradual process that occurs over long periods of time.
(B) Variation occurs among individuals in a population.
(C) Mutations are the ultimate source of genetic variation.
(D) Individuals that possess the most favorable variations have the best chance of reproducing.
(C) Mutations are the ultimate source of genetic variation.
This was not part of Darwin’s original theory of evolution.
CRB Define Differential Reproduction. Does it relate more to Darwinism or Neo-Darwinism?
The term Differential Reproduction describes Mutations or Recombinations that lead to advantageous phenotypes (typically meant as increasing reproductive success) are more likely to be passed on to future generations.
Since this term accounts for genetics, it is more closely related to Neo-Darwinism.
An organism’s relative fitness is measured by fecundity. What does this mean?
An organism’s relative fitness is measured by fecundity, which is basically the ability of one to survive and reproduce offspring. In other words, fitness is measured by the contribution to the gene pool of the next generation.
Which of the following are other modes of Natural Selection?
I. Sexual Selection, where mates are chosen for certain traits/phenotypes, which will be more likely to be seen in future generations.
II. Kin selection, where one animal will sacrifice itself to save its genetically-similar family members or pack.
III. Visual Selection, where only the most physically appealing specimens will reproduce and have their traits seen in future generations.
(A) I only
(B) I and II only
(C) II and III only
(D) I, II and III
(B) I and II only
Each of the following are modes of Natural Selection:
I. Sexual Selection, where mates are chosen for certain traits/phenotypes, which will be more likely to be seen in future generations.
II. Kin selection, where one animal will sacrifice itself to save its genetically-similar family members or pack.
What is the difference between natural selection vs group selection vs artificial selection?
Natural selection is favoring some individual organisms over others, and leading to the evolution of traits that benefit individuals themselves.
Group selection is the idea that genetic traits that benefit the population as a whole will be selected even if it does not increase the fitness of the individual with the trait.
Artificial selection is a result of the whim of man, thus we may prefer to choose a characteristic which would have never been selected by nature.
The studies of changes between black and light color in populations of the Peppered moth show which of the following:
(A) Natural selection can quickly change allele frequencies and common phenotypes in a population
(B) Species can always adapt to environmental changes
(C) Predators prefer light colored moths
(D) Dark colored moths are physiologically superior to light colored moths
(A) Natural selection can quickly change allele frequencies and common phenotypes in a population.
The studies of changes between black and light color in populations of the moth show that natural selection can quickly change allele frequencies and common phenotypes in a population.
Genetic drift will increase or decrease genetic diversity in dynamic population?
Genetic diversity is decreased through genetic drift.
Imagine that aliens were found on another planet filled with water, and their life forms looked a whole lot like Earth’s fish. Which type of evolution would this most be like?
(A) Divergent Evolution
(B) Parallel Evolution
(C) Convergent Evolution
(D) I will go read about the 3 main patterns of evolution and come back!
(C) Convergent Evolution
There is no reason to assume that these aliens and Earth’s fish are related, so the fact that they have evolved similar characteristics should be chalked up to Convergent Evolution.
Gene flow will increase or decrease genetic diversity in dynamic population?
Genetic diversity is restored by gene flow.
Which of the following is most likely to result in the loss of rare alleles?
(A) Founder Effect
(B) Genetic Drift
(C) Gene Flow
(D) Bottleneck Effect
(B) Genetic Drift
Genetic drift is most likely to result the loss of rare alleles because if an allele has a high frequency of at baseline, the chance of it being passed down to subsequent generations is higher than alleles at a lower frequency. The Founder Effect and Bottleneck Effect are specific examples of genetic drift.
Describe the relationship between Evolution and Natural Selection.
Natural Selection is one mechanism that Evolution can occur through, but Evolution can occur through other mechanisms too. This means that Natural Selection and Evolution are NOT synonymous.
A gene seeks only to be passed along to offspring if there are other copies of the gene in other individuals and the success of other individuals to reproduce. What does this concept illustrate?
(A) Natural Selection
(B) Group Selection
(C) Artificial Selection
(D) Inclusive Fitness
(D) Inclusive Fitness
This concept illustrates concept of inclusive fitness: a theory suggesting that the genetic success of an organism is dependent upon cooperation with other individuals in a population. A gene will be more prevalent in future generations if all individuals who carry that gene are successful at reproducing, rather than just one individual with that gene.
Eldrige and Gould had their own theory of evolution, based on fossil records showing little change over long periods, followed by short periods with lots of increased diversity and evolutionary changes. Which of the following is the name of their theory?
(A) Differential Evolution
(B) Epochal Evolution
(C) Punctuated Equilibrium
(D) Differential Equilibrium
Eldrige and Gould had their own theory of evolution, based on fossil records showing little change over long periods, followed by short periods with lots of increased diversity and evolutionary changes. Which of the following is the name of their theory?
(A) Differential Evolution
(B) Epochal Evolution
(C) Punctuated Equilibrium
(D) Differential Equilibrium
