UConn BIOL 1108 Final Exam (exams 1&2)

the only evolutionary process that leads to adaptive change

natural selection

you have spent time working with a population of salamanders. males range in size form 2-6 cm in length. you realize that the females only mate with the males that measure less than 3 cm long. you know that body length is controlled by a single locus in these salamanders. if you measured allele frequencies for that trait, would you expect to find that this population is in Hardy Weinberg equilibrium from one generation to the next?

no

in New Mexico, large expanses of black lava create patches of unique habitat. in every generation, selection favors the darkest colored fur in pocket mice in those habitats because they are best hidden from predators. the dark fur color of these tiny mammals is an example of:

directional selection

you have two populations of flowering plants. in these populations floral color is controlled by one gene. the red allele (Z) is dominant to the white allele (z). in population 1, 40% of the flowers are red. in population 2, 60% of the flowers are white. assuming H-W which population has a greater frequency of the Z allele? (recall p+q and p^2+2pq+q^2)

neither, they both have the same frequency

in a (H-W equilibrium) population of Supreme Digger beetles living in Tanisha's backyard, the frequency of dominant yellow winged beetles is 75%. can we determine allele frequencies? why or why not?

yes, the dominant phenotype can be either YY or Yy, so this means the frequency of y is 0.50 (the square root of 0.25)

match the concepts to the statements. you may or may not use a concept more than once or not at all. choose the best concept for each statement.

drift with bottleneck effect - elephant seals hunted to near extinction

evolution - change in allele frequencies in a population

gene flow - movement of alleles between populations

drift with founder effect - a few individuals colonize a new island

genetic drift - random change in an allele frequency due to predation

genetic drift - bottleneck and founder effects are types of this

you find that a wild population of bull snakes is not hardy Weinberg equilibrium. from this information alone, you can determine the mechanism of evolution operating on the population.

false

the term "N" refers to the number of individuals in a population. in general, in a sample of "N" individuals, the frequency of an allele is

the number of occurrences of the allele divided by twice the number of individuals in the sample

different species of fruit flies occupy each of the islands in the Hawaiian island chain, a group of volcanic islands that formed one after the other. one hypothesis for how the different fruit fly species formed, is that, after each new island was formed, fruit flies from existing islands colonized it and subsequently diverged. if this hypothesis is correct, it would be an example of:

allopatric speculation via dispersal followed by adaptive radiation

two species of frog have a mating season in the same pond. one breed in early summer and one in late summer. this is an example of what kind of reproductive isolation

pre zygotic, temporal (time) separation

according to the biological species concept, two individuals of opposite sex are members of the same species if:

they can produce fertile offspring

unlike the biological species concept, the morphospecies concept relies on:

phenotype

horses and donkeys can interbreed, but their offspring (mules) are infertile. this is an example of what kind of reproductive isolating mechanism?

post zygotic, genetic incompatibility

match the concepts to the statements. you may or may not use a concept more than once, or not at all. choose the one best concept for each statement.

directional selection - one extreme trait is favored in the environment

disruptive selection - both extremes of a trait are favored in the environment

stabilizing selection - the intermediate trait is favored in the environment

in a phylogenetic tree, a node represents:

the common ancestor from which the descendant species diverged

which phylogenetic group includes a common ancestor and all the descendants of that ancestor?

monophyletic

with the advent of tools to incorporate molecular data, phylogenetic analysis can be used to:

all of the answer options are correct

when comparing phylogenetic trees showing various hypotheses of evolutionary relationships between a group of animals, the tree with _____ would be the weakest candidate

the most changes

two taxa which are more closely related to each other than any other taxon are called:

sister groups

molecular phylogenies show all land plants are a monophyletic group. this suggests that

there was a single transition from aquatic to terrestrial habitats

the fossil record provides us with direct evidence of evolutionary history

true

a phylogenetic tree is a

hypothesis about the evolutionary history of taxonomic groups

why do we believe that "at the least" male Homo sapiens neanderthals mated with non-African ancestral Homo sapiens sapiens?

because neanderthal nuclear DNA sequences are present in the human gene pool

how does the level of genetic variation in humans typically compare to other species?

lower than other species

one reason we see relatively little genetic variation among human regional populations is that:

humans migrated out of Africa so recently that we haven't had enough time for regional variation to accumulate

adult humans display several traits very similar to traits seen in juvenile of our sister group, the chimpanzees. what is the evolutionary explanation for this?

some adult human traits are thought to be neotenic

humans are members of the monophyletic

great ape group

the fossil "Lucy" is significant because, at ____ years old, this is the first species known to

3.2 million; be fully bipedal

you inherited from your mom both her straight nose and her recipe for chocolate chip cookies. both are very favorable traits. which trait will spread more quickly through the population?

the recipe, because it can be passed on to all relatives through learning

to which super kingdom does the organism that causes amoebic dysentery belong?

amoebozoa

why do mitochondria and chloroplasts have small genomes?

because over time, much of they nucleic acid has migrated to the host cell nucleus or become unnecessary

to which superkingdom do camels belong to?

opisthokonta

why is the eukaryotic tree of life unrooted?

the most ancient common ancestor is not known

8 hundred million years ago, what change in atmospheric conditions coincided with an increase in eukaryotic diversity?

increase in O2

red tides are caused by organisms in the Superkingdom Ranelamintha

false

how do eukaryotic cells build and maintain genetic diversity?

through sexual reproduction

a symbiont is an organism that lives in close association with another species

true

a heterotrophic protist builds its own food through photosynthesis

false

whales belong to the superkingdom archaeplastida

false

photosynthesis has evolved only one times in living organisms

false

chloroplasts are thought to have evolved in protist groups from every kingdom

false

which of the following is a characteristic of complex multicellular organisms, but not simple multicellular organisms?

the functional specialization of subsets of cells in the organism

a coenocytic organism is

multinucleated

cardiac muscle cells have gap junctions between adjacent cells. what is the function of those gap junctions?

they are involved in cell-cell communication of the cells of the heart

the evolution from simple multicellular organisms to complex multicellular organisms required

the development of a system that enabled bulk transport

which of the following is a characteristic of complex multicellularity?

interior cells are exposed to a different physical and chemical environment than exterior cells

most taxonomic groups with simple multicellular organisms never gave rise to complex multicellular descendants

true

the branch of biology known as evolutionary-development (evo-devo) focuses on

how mechanisms of the development of organisms have been influenced by evolution

which of the following statements about diffusion is false?

it transports materials actively along a concentration gradient

complex multicellularity evolved multiple times in living organisms

true

how do the two species that make up lichen benefit from their symbiotic association?

the fungi receive carbohydrates and, in some cases, nitrogen from the algae, while the algae gain a "home" that anchors them on the substrate

how do fungi digest their food sources?

by secreting enzymes externally, directly into their surrounding environments

remnants of a decaying tree

on a hike through the forest, you notice a circle of mushrooms, each with a stalk, cap, and gills on the underside of the cap. if you dig into the soil below the ring, which of the answer choices might you find?

moist soil

which of these locations is a point of entry through which viral and bacterial pathogens can infect plant tissues?

open stomata

in both bryophytes and vascular plants, meiosis occurs in the dominant or most conspicuous phase of the life cycle

false

in bryophytes and some vascular plants, the sperm swims to the egg

true

in which lettered location in the figure would you find electrons moving between large protein complexes?

thylakoid membrane

in which of the lettered locations in the figure would you find carbohydrates synthesis taking place?

stroma

in which lettered location of the figure is light initially captured?

thylakoid membrane

the multicellular sporophytes of bryophytes are haploid

false

which of the fungal structures aid in spore dispersal?

fruiting bodies

during which of the processes does the cytoplasm of two hyphal cells fuse to form a eukaryotic (n+n) cell?

plasmography

a researcher isolates a species of fungus that only reproduces sexually. he introduces individual hyphae, all of the same mating type (i.e. with the same mating-type alleles), into a Petri dish. what do you expect will happen with the fungi in the dish?

no spores will be formed by the fungi in the petri dish

angiosperms only provide energy-rich nutritive materials to ovules that have been successfully fertilized, whereas gymnosperms typically provide those resources even to unfertilized, and therefore sterile, ovules. what accounts for this angiosperm advantage?

double fertilization

about two-thirds of human caloric intake consists of wheat, rice, and corn. what tissues constitute the majority of the nutritional content of the plant-based foods?

endosperm and female gametophytes

which of the challenges faced by plants in the early colonization of the land was solved by a change in the life cycle to "alternation of generations"?

fertilization of the egg and dispersal of offspring

the xylem of angiosperms is composed of ______, allowing these plants to thrive in tropical climates and have high rates of photosynthesis. gymnosperms are successful in cold climates because their xylem is composed of ______, which reduce the risk of cavitation due to freezing.

vessels, tracheids

oil and coal are what remain of ancient forests after millions of Yeats of exposure to subterranean high temperatures and pressures. what group of land plants is though to have contributed most to this fossil energy source?

lycophytes

A seed from a yew tree germinates on the forest floor. During the first few months of its life, the sapling dedicates most of its resources to increasing in height rather than producing the defensive compound taxol. What is this allocation of resources an example of:

a trade-off

which of these organisms can act as plant pathogens?

bacteria

Why do ant-plants invest in nectaries and protein/lipid food bodies on their young leaves?

it encourages the ants to visit these plant tissues which are most vulnerable to herbivory.

what methods do grasses employ to deter herbivores and survive heavy grazing?

grass shoot apical meristems remain close to the ground

nitrogen is required to synthesize which of these defensive compounds (which are, as a result, very costly for plants to produce)?

alkaloids

Milkweed plants produce a variety of defenses, such as leaf hair and latex-filled canals, to deter herbivores. How can monarch caterpillars circumvent these obstacles?

by cutting the veins that transport latex through leaves

Recall that the bullhorn acacia forms a symbiosis with P. ferruginea ants. A researcher takes an acacia seed and plants it in an area without P. ferruginea. What will happen to this acacia plant?

without P. ferruginea, the plant won't form any new defenses and will be eaten by herbivores

which of these statements is evidence for an arms race between plants and their antagonists?

diversification of the herbivorous insects and plants occurs at the same time over evolutionary time

why is it significant that pollen contains a multicellular male gametophyte instead of just male gametes?

the non-gamete cells of the male gametophyte control the growth and development of the pollen tube

what would be the result if the gamete release took a gamete to an environment not previously colonized by that species?

failure to colonize the new environment

which of the plant groups first developed a sporophyte that becomes self-sustaining (I.e. is not dependent on the gametophyte for nutrients)?

ferns

in the life cycle of mosses and ferns, which of the structures are diploid?

sporophyte

how do seeds compare to spores as dispersal units?

Seeds are larger and heavier and require extra investment in tissues that aid dispersal

which of the processes occurs in angiosperms when a sperm cell fuses with a haploid (1n) egg, and a second sperm merges with a diploid cell within the future seed to form the endosperm?

double fertilization

within the stem of a vascular plant, where would you expect to find the cells that are the most mature?

at the base of the stem near the soil

recall that in many plants, if the shoot apical meristem is removed, axillary buds become active and new lateral branches form. What is this an example of?

apical dominance

you purchase two identical houseplants and place them side by side on your windowsill. you water both plants equally. you leave plant A alone, but you pinch off the top of the growing stem of plant B, effectively removing the apical meristem. which results would you expect to occur?

plant B will be much bushier, with growth of many lateral branches

which structure is the source of new cells that allows mature stems to grow in diameter?

vascular cambium

vascular cambium is one of two lateral meristems; the other is cork cambium. a plant grows in diameter primarily through divisions of the vascular cambium. if you pull a small piece of bark off of a tree and look at the bark's inside surface, what tissue are you looking at? ignore any remaining cells of vascular cambium that may be left.

phloem

a botanist is studying the growth of rings of a redwood tree. she notices that three concentric rings are very thin compared to the surrounding growth rings. what can she deuce from the presence of these thing growth rings?

that tree may have experienced a rough or had limited access to nutrients during that time period

a houseplant is growing on your windowsill. every Sunday, without fail, your roommate turns the plant 180 degrees. when you ask your roommate why she does that, her reply is simply, "I want straight plants." does this method produce straight plants?

yes. rotating the plant will even the growth of the plant toward the light changing where the light hits the plant every week.

the formation of branches in a root allows the root to maximize surface area for the absorption of water and nutrients. how is that the new branches may begin transporting resources to the plant almost as soon as the branch is formed?

the new branch forms from the pericycle, which is in contact with the vascular cylinder of the root.

One of the earliest evolutionary adaptations that helps plants to retain water in a terrestrial environment is the:

cuticle

what is the role of the PEP carboxylase enzyme during both CAM and C4 photosynthesis?

to capture CO2 in the form of 4-carbon organic acids

CAM plants do not operate the Calvin cycle at night because:

it requires ATP and NADPH which are made only during daylight.

water transport in the xylem depends on:

hydrogen bonding between H2O molecules

which of the answer choices are accurate statements about both root hairs and mycorrhizae?

both increase in the surface area for nutrient uptake

photosynthesis in green plants is composed of the ______ in which H2O oxidized, and ________, in which CO2 is reduced

photosynthetic electron transport chain; the Calvin cycle

which of the following answer choices is an advantage of having two slightly different photosystems in the chloroplasts?

the electrons can be elevated to a higher energy level than is possible with a single photosystem.

In plants, the initial electron donor in photosynthesis is:

H2O

carbon enters the Calvin cycle in the form of:

CO2

in the evolution of photosynthesis, which of these processes happened first?

the acquisition of two photosystems by cyanobacteria