EXIT QUIZS Flashcards
In a community that is regulated from the bottom up, the abundance of plants is regulated primarily by ________________. Still, when it is regulated from the top down the effect of herbivory is _______________.
the availability of resources, intense
Why did the average size of the medium ground finches on Daphne major increase in size during the 1976 drought but decrease in size in ~2005?
Selection favoured larger beaks in the 1976 drought as they were better able to acquire large, hard seeds. In the 2005 drought, the presence of large ground finches out-competed the large-billed medium ground finches for these seeds, resulting in the greater success of smaller-beaked medium ground finches.
Which of the following is a FALSE STATEMENT about how the presence of a predator may affect species richness
The removal of a predator always leads to a greater number of species in a community
Which of the following indices of communities does NOT incorporate information on the relative abundance of the species in that community?
Species Richness
Which of the following is a consequence of charcter displacement?
The co-existance of sympatic species.
According to the facilitation hypothesis, what is the BEST explanation for why early colonizing species disappear from the community?
Their modification of the environment makes it less suitable for their continued survival, and more suitable for other, later-arriving species
A species experiences prolonged directional selection, resulting in the evolution of larger body size. What other changes to that species’ life history traits are likely to accompany this change in body size?
Longer generation time and smaller brood sizes
The age structure diagram of a population experiencing exponential growth will be ________; one that is >K will have a diagram that is _________
wider at the base; narrower at the base
A short generation time….
A. is typical of a r-selected species
B. is usually seen in small-bodied species
C. is typical seen in species with small rMAX values
A & B
In a mark-recapture study, an initial sample of 50 fish is captured, marked and re-released into a population, whose size is unknown.
Later, in a sample of 200 fish, 5 of the marked individuals is recovered.
Based on this data, what would you estimate the population size to be?
2000 fish
At what point in time is the rate of growth in a population experiencing logistic growth (LG) approximately the same as one experiencing exponential growth (EG)?
When the LG and EG populations are small
In a large (N=K), well-established population subject to logistic growth, a sudden decrease in the carrying capacity of the environment will lead to….
… a period of negative population growth, with the per capita population growth rate approaching 0 as the population size approaches the new carrying capacity.
High rates of survivorship in adults should favour the evolution of which life history strategies?
Production of few offspring needing much parental care
A species of plant grows in an environment where resources in the soil (i.e. nutrients, water) are extremenly rare, and are unevenly distributed across the landscape. Which of the following distribution is most likely for this species.
clumped distribution
What term best describes the relationship between auxin and ethylene?
antagonists
Which hormones would you expect to see in higher concentrations in plants during the late Summer & early Fall?
Ethylene and ABA
In the case of Walter & Paterson’s experiments, inducing a SAR response in parents had what effect(s) on their offspring?
Offspring were better prepared to withstand an a potential infection, compared to the control plants’ offspring.
The production of ________ in the tips of stems promotes ________ at the expense of _________, a phenomenon known as __________.
Question options:
auxin
axial growth
lateral growth
apical dominance
How does auxin mediate the gravitropic response of roots & shoots?
Auxin accumulates on the downwards-facing side of the stems and the roots. In the shoots, the increased auxin promotes greater cell-elongation, causing the tip of the stem to bend upwards. In the roots, the increased auxin inhibits cell-elongation, causing the tip of the root to bend downwards.
he left side of the phylogeny below depicts the cultivars of Brassical rapa (while the right side is our old friend and B. oleracea).
In both groups, there is a cultivar called cabbage. What is the most likely reason for their similarity?
Selection for the same traits by domesticators led to similar phenotypes over time
Treating a plant stem with a “mystery” plant hormone results in increased cellular division and elongation compared to a control plant stem. What kind of plant hormone is being used?
Auxin
In the case of diplostigmaty, what did the experimental removal of the apical stigma reveal about reproduction in Sebea aurea (see Fig 2 in the Kissling & Barrett paper)?
That the basal stigma is functional, and that this species is self-compatible.
What kind of fruit typically develops from a single flower that has a single carpel?
Simple fruits
What is a benefit of self-incompatability?
Offspring are potentially more genetically diverse
A seed undergoes “imbibition” because the inside of the seed has a ____ water potential compared to the water around it, and water molecules ______.
lower move into the seed’s cells
What kind of germination results in the cotyledons being pushed out of the ground?
Epigeal germination
Which of the following is a potential downside of vegetative reproduction?
There is decreased genetic diversity in the population as a result of vegetative reproduction
In angiosperms, which two cells of the embryo sac are fertilized by the two sperm cells?
The egg and the central cell.
Herkogamy reduces the chance of self-pollination by changing the _________ of the stigma and the anthers, while dichogamy changes the ______ of the stigma and the anthers.
physical location
timing of maturation
In the diagram below, what part of the flower is indicated by the number 11?
The sepals, the non-fertile whorl of the flower.
Which term best describes a solution that contains a lower concentration of dissolved solutes than is found inside a cell?
Hypotonic
Crassulacean acid metabolism (CAM) photosynthesis is found in over 400 genera vascular plants scattered across 36 families. Different groups employ different enzymes to catalyze malate decarboxylation. In such cases of convergent evolution, CAM photosynthesis can be thought of as…
homoplasious
In the process of cation exchange, plants are able to liberate __________ that are bound to the surface of clay particles by actively transporting ___________ out of their hairs into the surrounding soil.
Positively-charged ions; CO2 and H+
Which of the following best describes the plasma membrane of plant cells?
Selectively permeable
What is the driving force for water and solute movement through the phloen?
A positive pressure generated at the source by the loading of sugars by the companion cells into the sieve cells
How do the soils of a typical coniferous forests compare to those of a typical deciduous forest?
a - The coniferous forests experience more leaching
When molecules move via active transportation there is a net movement from areas of ______ concentration to areas of _______ concentration, while molecules moving via passive transportation (such as by diffusion) move ______ their concentration gradient.
high low against
Which ONE of the following FIVE options is NOT a potential consequence of extensive acid rain?
An increase in the rate of nitrification in the soil
Why should you cut the stems of your store-bought flowers before placing them in a vase of water if you want to prevent them from wilting?
To prevent air bubbles from forming in the xylem, which would disrupt the water tension
What explains the similarity in purpose of the leafy jaws of Dionaea muscipula and the pitcher structure of Nepenthes lowii?
Similar selective pressure from their environment
Which of the following functions a property of BOTH roots and stems?
Transporation of nutrients
Plants grow throughout their entire lives because of ______ that continues to divide.
meristem tissue
Which of the following is the best description of sclerenchyma cells?
Cells with highly-lignified secondary cell walls, that are dead upon maturity
In a woody eudicot, what is the fate of primary phloem?
Primary phloem will become crushed between the secondary phloem and the bark, as secondary growth proceeds.
Which layer of cells within the dicot root retains the capacity to divide and start the development of secondary (lateral) roots?
Pericycle
Leaf tendrils and stem tendrils are examples of what phenomenon?
Convergent Evolution
In a woody eudicot, which of the following indicates the correct ordering of plant tissues, from the outside of the stem to the inside?
Primary Phloem
Secondary Phloem
Vascular Cambium
Secondary Xylem
Primary Xylem
In what way is the structural organization of eudicot stems similar to that of monocot roots?
In both groups, vascular bundles are arranged in a circle, dividing the ground tissue into the cortex and pith
Which of the following is NOT a characteristic of a dicot?
Leaf veins parallel
in exogenous trees, the youngest material is found near the ______, while in an endogenous tree, the youngest tissues will be found near the ____.
outer surface of the stem; centre of the stem
What do leaf tendrils and cactus spines represent?
Homologous structures
What kind of phylogenetic tree is the LEAST informative?
An unscaled, unrooted tree
What kind of phylogenetic tree is depicted below?
A rooted, scaled tree
The IGF1-AS variant (aka “allele”) rs22397284 that is associated with large dogs differs at the highlighted location when compared to other genetic sequences. What is the most plausible explanation for the evolution of this allele?
The common ancestor of the dogs, pandas, ferrets and cats all had “C” at that base pair location. After the dog lineage split for the others, there was a C to T substitution mutation.
The similarity of homoplasious traits is due to ____________, while the similarity of homologous traits is due to ___________.
convergent evolution; common ancestry
Which of the following groups is NOT a monophyletic group?
Charophyta
From the perspective the common ancestor of the primates, rodents and rabbits, crocodiles and birds, in this phylogenetic tree the Amniotic egg is a _________ trait, while a bony skeleton is a ________ trait.
derived; ancestral
The group “Reptilia” has been traditionally defined as including the turtles, lizards, snakes, and crocodiles (but not birds). What kind of phylogenetic grouping is this?
A paraphyletic group
A recent study has reported that in ornithischian (bird-hipped) dinosaurs that the secondary evolution of quadrupedality from a ancestral bipedal state happened independently at least THREE times, and in each case the change is associated with very different mechanically solutions (in other words, the relevant forelimb muscles evolved in different ways to cope with the increased load-bearing pressures). This is an example of __________. If we grouped these clades of newly-quadrupedal dinosaurs together into a single cladistic group we would be creating a __________.
convergent evolution
polyphyletic group
Which group(s) is most closely related to the Amphibians?
Crocodiles, Birds, Primates & Rodents/Rabbits (equally)
According to the phylogenetic tree depicted below, which is the “most advanced”?
All are equally “advanced”
The “mega-gel” evolution video illustrates which phenomena?
All of the above
The appearance of the “Big Bird” species in the Galapagos is best described an example of what phenomena?
Punctuated Equilibrium via hybridization
In wild varieties of grains _________ is a phenotype favoured by _________ selection, while for a domesticated grain ______ is favoured due to the action of ________ selection
dehiscence
natural
indehiscence
artificial
For a population to undergo adaptive evolution via natural selection which of the following factor(s) MUST be present?
Only A, C & D are necessary
The genetic sequence of a homeotic gene in two distantly related species is compared and are found to be extremely similar in sequence. What can you infer about this situation?
That the phenotype associated with this gene experiences strong stabilizing selection in both species.
BONUS QUESTION: Prior to the industrial waste clean-up in Manchester & Liverpool the allele responsible for the typica morph was still present in the gene pool of peppered-moths (Biston betularia) collected in those cities. What is the most plausible reasons for this observation?
the allele in question is recessive & autosomal
Which of the following statements is NOT a correct statement/prediction about the future of the SARS-COV-2 virus?
The virus will inevitably evolve to become less deadly over time
The diversity of species of Darwin’s finches in the Galapagos is an example of _______, arising primarily due to ________.
an adaptive radiation
natural selection acting on (largely) allopatric populations
Which ONE of the following is an accurate statement regarding the evolution of species?
Individuals experience selection but cannot evolve
Which ONE of the following statements regarding the case studies of the peppered-moths (Biston betularia) and the spindle ermine moths (Yponomeuta cagnagella) is accurate?
That an individual’s fitness is conditional on it’s environmental context
What is a consequence of differences in competitive ability of individuals in a population?
Differences in the opportunity to pass on alleles to the next generatoion
What pattern of speciation could arise if a group experience prolonged stabilizing selection?
Anagenesis
Which of the following is the most common way in which new species form?
Allopatric speciation
A speciation event that occurs as a result of disruptive selection acting on a population that straddles an environmental gradient is an example of:
Parapatric speciation
Which of the following modes of reproduction can be accomodated by the Biological Species concept?
Sexual Reproduction
According to the morphological species concept, a species is a population of organisms…
… that are similar in anatomical characteristics.
What mechanism of speciation is MOST likely to explain the pattern of co-divergence of populations of Galápagos hawks (Buteo galapagoensis) and a parasitic feather louse species (Degeeriella regalis)?
geographical isolation
What is the greatest challenge to a successful sympatric speciation event?
Potential homogenization due to gene flow between groups
Why does substantial intra-specific (within species) variation pose difficulties when applying the Morophological Species concept?
You may accidentally decide that you are looking at >1 species.
In the Biological Species concept ______ causes species to remain separate and distinct from each other, while in the Ecological Species concept ________ is the mechanism for speciation.
a lack of gene flow
selection
According to the Differential Fitness Species Concept, can individuals from different species exchange genes and still be considered different species?
Yes, provided that the genes exchanged have no deleterious effect on fitness.
Why are chromosomal inversions of great potential importance to the potential sympatric speciation of apple maggot host races?
They are an area of decreased recombination.
What does the Morphological Species Concept have in common with the Phylogenetic Species Concept?
Both define species based on the presence of unique features that are not seen in other groups.
Which ONE of the following FIVE statements CORRECTLY describes the position of the gametophytes in the plant life cycle?
Gametophytes develop from spores
Which of the following trait(s) assist in plants obtaining nutrients from the soil?
A & B
Which of the following is NOT a derived trait in the Seedless Vascular plant lineages?
Cuticle
If you were creating a cladogram of the land plants, which taxa from the following list would be most appropriate to designate as your “outgroup”?
a bryophyte
Which of the following is NOT a trait that has evolved in response to selection for survival in an arid, terrestrial, environment?
All are the product of selection for survival on (dry) land
Your friend bring you a mystery plant with the following characteristics: sporophyte dominant, pollen grains, and flowers. This plant belongs which group?
The angiosperms
The occurance of of wind pollination in some angiosperm as well as in gymnosperm pollen are likely due to…
Convergent evolution
In the figure below are the seven possible phylognetic trees that represent the evolution of land plants. In which tree(s) are the brypothytes
A
The presence of pollen in BOTH the angiosperm and gymnosperm taxa is LIKEY an example of….
Homologous traits
In the figure below are the seven possible phylognetic trees that represent the evolution of land plants. I have superimposed circles to represent the theoretical necessary location of derived character states, to account for the appearance of these different lineages. Given the information provided, which of these tree(s) is(are) the most likely to be the correct representation of evolutionary history?
The plot contains derived character traits, with solid blue indicating the evolution of lignin, solid green indicating the appearance of the stomata, and (in some cases) the empty green circle indicating the loss of stomata.
E, F, & G
Which was the first taxonomic group to exhibit heterospory?
The seedless vascular plants
According to the mathematical model of Kimura & Ohta (Genetics 61, 763-771 (1969)) for genetic drift which of the following populations is most likely to be the first to see the complete loss of genetic diversity at a given gene loci (where we assume there are only 2 alleles “A” & “a”, no immigration or emigration, the population size remains constant, mating is random, there are no new mutation, and no selection)
Initial population size of 100, f(a)=0.9
BONUS:
I have been maintaining a population of fruit flies (Drosophila melanogaster) in my lab under conditions in which there is random mating, large population size, no immigration/emmigration/mutation, and no selection (i.e. none of the assumptions of the Hardy-Weinberg model are violated). In this population I observe that 1% of the flies express the brown-eye phenotype (resulting from being homozygous for a recessive allele) rather than the wild-type red phenotype.
What is the frequency of the dominant allele at this genetic loci?
0.90
In cases of negative frequency-dependent selection, _______ phenotype typically has _______ fitness
the least common
the highest
At the gene that produces for alcohol dehydrogenase (ADH; an enzyme that is necessary for flies to metabolize and detoxify ethanol), there are two possible alleles: the dominant allele E, which codes for a functioning enzyme, and the recessive allele e (that, when expressed results in a phenotype incapable of metabolizing and detoxifying ethanol).
If I started a population in which the initial frequencies of both E and e alleles was 0.50 and cultured these flies for many generations (by mating them randomly in each generation and keeping them at a large population size with no chance of immigration or emigration), in an environment where I fed the developing flies food that contained significant amounts of ethanol, what would you predict would happen to this population over time to the frequency of the e alleles?
The frequency of the e allele in the population will decrease but will never be completely eliminated from the gene pool
From a collection of 100 fruit flies collected ourside of Wilf’s I found 81 individuals that were homozygous for the dominant allele E, 18 individuals that were heterozygous, and 1 individuals that were homozygous for the recessive allele e (and are thus incapable of metabolizing and detoxifying ethanol).
Is this population at Hardy-Weinberg equilibrium, and if not how are they different than would be expected?
The population is at Hardy-Weinberg equilibrium.
From a collection of 100 fruit flies collected ourside of Wilf’s I found 76 individuals that were homozygous for the dominant allele E, 14 individuals that were heterozygous, and 10 individuals that were homozygous for the recessive allele e (and are thus incapable of metabolizing and detoxifying ethanol).
Is this population at Hardy-Weinberg equilibrium, and if not how are they different than would be expected?
The population is not at Hardy-Weinberg Equlibrium as there are more homozygotic dominant and more homozygotic recessive, and fewer heterozygotic individuals that I would have predicted.
Which of the following statements best describes the key findings of Slade et al.’s research on mice?
Captive-reared and wild-mice were largely seen to mate with partners originating from their same group (i.e. assortatively). This will cause the offspring genotype frequencies to differ from those frequencies expected under Hardy-Weinberg equilibrium, likely with more homozygotes than would be predicted.
I have a sample of fruit flies where the frequency of the dominant allele, E (which codes for a functional ADH enzyme), is 0.1, while the frequency of the recessive allele e (which when homozygous renders the flies incapable of metabolizing and detoxifying ethanol) is 0.9.
If I was to randomly mate these flies, and ensured that none of the Hardy-Weinberg assumptions were violated the frequencies of offspring in the next generation would be:
EE=0.01
Ee=0.18
ee=0.81
I have a sample of fruit flies where the frequency of the dominant allele, E (which codes for a functional ADH enzyme), is 0.8, while the frequency of the recessive allele e (which when homozygous renders the flies incapable of metabolizing and detoxifying ethanol) is 0.2.
If I was to randomly mate these flies, and ensured that none of the Hardy-Weinberg assumptions were violated the frequencies of offspring in the next generation would be:
EE=0.64
Ee=0.32
ee=0.04
In a follow up study, I made another collection of fruit flies from the orchard, and sequenced the DNA of 100 individuals to determine their specific genotype at the autosomal gene locus that codes for alcohol dehydrogenase (ADH; an enzyme that is necessary for flies to metabolize and detoxify ethanol).
The results of this study revealed that there were 11 individuals that were homozygous for the dominant allele E, 72 individuals that were heterozygous, and 17 individuals that were homozygous for the recessive allele e (and are thus incapable of metabolizing and detoxifying ethanol).
What is the frequency of the wild-type phenotype (capable of metabolizing and detoxifying ethanol) in this sample?
0.83
I recently visited a local orchard where I collected 100 individual fruit flies (Drosophila melanogaster), and took them back to the lab. There, I sequenced the DNA of each fly to determine their specific genotype at the autosomal gene locus that codes for alcohol dehydrogenase (ADH; an enzyme that is necessary for flies to metabolize and detoxify ethanol).
The results of this study revealed that there were 30 individuals that were homozygous for the dominant allele E, 60 individuals that were heterozygous, and 10 individuals that were homozygous for the recessive allele e (and are thus incapable of metabolizing and detoxifying ethanol).
What is the frequency of the “E” allele in this sample?
0.60
I recently visited a local orchard where I collected 100 individual fruit flies (Drosophila melanogaster), and took them back to the lab. There, I sequenced the DNA of each fly to determine their specific genotype at the autosomal gene locus that codes for alcohol dehydrogenase (ADH; an enzyme that is necessary for flies to metabolize and detoxify ethanol).
The results of this study revealed that there were 20 individuals that were homozygous for the dominant allele E, 30 individuals that were heterozygous, and 50 individuals that were homozygous for the recessive allele e (and are thus incapable of metabolizing and detoxifying ethanol).
What is the frequency of the “E” allele in this sample?
0.35