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rj biol - set#1

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What flower whorl is collectively made up of petals? Which other flower parts are the petals of most flowers homologous, in what ways, and what is the origin of petals in some flowers?
The corolla is collectively made up of petals. The petals of most flowers are homologous with stamens in that both are affected by genes that do not affect either carpels or sepals. In a small number of flowers, petals evolved from sepals, which enlarged and developed color.
why higher DDT levels in carnivores vs. herbivores?
carnivores eat several herbivores, get sum of DDT. DDT can't be broken down, so accumulates in carnivores. Called biological magnification.
Define Biotic potential of a population, what is the definition for actual rate of pop. increase, what two factors effect it?
biotic potential of a population is the rate at which a given population will increase with no limits placed on it. The actual rate of population increase is the difference between birth rate and death rate per individuals per time. Two factors that affect it are emigration and immigration.
muellerian mimics
unrelated but similarily protected species w/similar aposematic coloration: bees wasps yellowjackets, mudwasps, stinging insects
What does alteration of generations refer to in plants. Distinguish between sporophyte and gametophyte. With which stage is an adult animal comparable? How are plants and animals reproductively dissimilar?
In plants, alternation of generations refers to alternation of a diploid generation with a haploid generation. Sporophytes are diploid, spore-producing reproductive structures; gametophytes are haploid, gamete-producing reproductive structures. The sporophyte is comparable to an adult animal, although it differs in that adult animals produce sperm and egg (gametes), whereas a sporophyte plant does not directly produce gametes.
effects of excess fertilizer to nitrogen cycle?
imbalance=cultural eutrophication=algae bloom=chain reaction. lack of heterocysts mean too much nitrogen (they then don't need to be there to produce it, also less denitrifying bacteria.) algae makes oxygen, photosynthesizes-->increase in organisms that eat algae, zooplankton. use up all oxygen. kill nekton(fish), less fish for birds etc. up through levels. Also lack of oxygen means conversion of nitrates and sulfites into hydrogen sulphide and ammonia. (bad.) also burns crop land, assists weed growth off crop land, fill in streams lakes, ponds. initial increase in plant growth means more herbivores, carnivores and detritivores, then more imbalance and limiting factors. (all bad.)
How does predation help maintain communities that are rich and diverse in species?
Predation contributes to the elimination of the sick, weak, and genetically inferior members of prey populations.
density dependent population limiting factors?
food, shelter, light, access to mates, space, disease, parasites, predators. intra and inter species competition, demography - %of pop. at or approaching reproductive phase.
What is a biome? What two key factors affect distribution of biomes around earth?
A biome is an assemblage of organisms that has a characteristic appearance and that occurs over a wide terrestrial geographical area. The two key physical factors that effect the distribution across the earth of biomes are (1) amounts of heat that reach the earth and its seasonal variation and (2) global atmospheric and resulting oceanic circulation patterns.
why does net productivity decrease with more mature ecosystem?
more biomass uses more energy=less production. net productivity is measure of all organic matter produced, less amount used to create organic material available. more mature ecosystem means more biomass consuming more of primary product - more energy and material required to sustain and fuel older ecosystem, consume more net product.
Three types of dispersion in a population? Which most frequent in nature, & why?
random spacing, even spacing, and clumping. Most frequent in nature = clumping, because specific environmental conditions are neither randomly nor evenly distributed. Animals congregate for various reasons, young of a species are likely to be near the parents.
evolution of life from simple molecules through to appearance of eukaryotes
aggregations of chemicals in oceans on earth --> protocells = differentiation of fluids inside vs. outside "cell" -->some had amino acids, catalyzed reactions that permitted growth, increased longevity-->'selection' passed on to offspring=hereditary basis of life-->offspring created by buds in bilipid or protein membrane, pinched off-->protein first or lipid controversy?RNA - need for heredity-->then bacteria-->pelomyxa (early eukaryote)-->eukaryotes. possible origin of eukaryotes from prokaryotes=endosymbiosis.
HOw does the reproductivity and colony size of social versus solitary bees relate to the kinds of flowers that they pollinate. Is it more likely that a flower visited by a social or solitary bee will become highly specialized toward that be and why? How
Social bees have large colonies and must visit many types of flowers to get enough food; they produce several generations over a summer and must vary their flower choices over time as well; solitary bees have only a single brood to raise and use only a single type of flower. It is more likely that this flower will be visited by a solitary bee because it visits only a single type of flower; thus they can evolve together. Coevolution is advantageous to both parties as follows: plants get an efficient, reliable source of pollination and the bee gets a constant source of food.
why coast of bc so productive - capacity to support fish vs. mid-pacific?
more food. proximity to land. nutrients from land. shallower water from coast to continental shelf=more sunlight. more photosynthesis. more plankton, more nekton. also upwelling hapens here, provides addt'l nutrients, and wave action contributes additional oxygen to water. Mid pacific=no benefit of land nutrients, too deep, not so much sunlight/photosynthesis, not as conducive to food production, less oxygen, no upwelling.
Of aposematic colouration, cryptic colouration, and batesian mimicry, which is associated with an adult viceroy butterfly? Which with a larval monarch butterfly, which with a larval viceroy butterfly?
The adult viceroy butterfly exhibits Batesian mimicry; the larval monarch butterfly exhibits aposematic coloration; and the larval viceroy butterfly exhibits cryptic coloration.
features that define life and why each feature necessary?
1organization of cells w/in org=div. of labour, allows metabolism, growth, continued life, passing along of gen. mat.
2.assimilation of carbon compounds: metabolism - provides energy for life
growth:internal accumulation of cells - (not like icicles)
ESSENTIAL: hereditary transfer mechanism is CRUCIAL To adaptation.
5. reproduction - continuation of species of organism, facilitate adaptation, longevity of species.
How do eutrophic lakes differ from oligotrophic lakes, which is more susceptible to pollution and why?
Eutrophic lakes = organic + abundant minerals; action of decomposers makes the hypolimnion stagnant during the summer. Oligotrophic lakes = scarce organic matter and nutrients; generally deep with abundant supply of oxygen in the hypolimnion. Oligotrophic lakes more susceptible to the effects of pollution because excess phosphorus from fertilizers increases productivity, which depletes the lake of oxygen.
autotrophs without heterotrophs in long term?
nope.autotrophs need carbon dioxide produced by heterotrophs breathing in oxygen produced by autotrophs. Same with other nutrients. heterotrophs are also decomposers and contribute other nutrients to forms that plants can use.
Why is it best to harvest individuals of a productive population partway up the sigmoid growth curve rather than when the population is at carrying capacity? What is the result of harvesting small populations?
Partway up the sigmoid growth curve reflects a rapid growth phase, and yields will therefore be better longer, extending the period of rapid growth. Harvesting small populations results in overharvesting, destroys long-term productivity, and increases the likelihood of extinction.
advantages of living in groups
decreased risk from predators (or of being one eaten), more to look out for predators, common "brain" knowledge where food volume and types can be found, stronger individuals within group. greater protection for young - sometimes larger numbers of young born. (offsets disease and parasite losses)
Discuss three ways that seeds reached the Hawaiian islands. What types of structures aided the seeds in their dispersal?
Seeds were buoyant and floated to the island; were carried by birds either on their bodies or inside their bodies as food; small and light seeds were blown to the island.
grassland vs. tundra - which more stable?
in general - diversity means stability. Grasslands able to support more. deep soil, sufficient water, good agric. Tundra=harsh. tenuous balance, organisms must store food, short growing period, permafrost. resilient organisms, but delicate balance.
What numerical relationship must exist between aposematically coloured individuals and batesian mimics, why?
must be much smaller # of mimics than aposematics. If same number of or more mimics, predators will have a good chance of getting an unprotected individual rather than a protected individual and will not learn avoidance of the model.
disadvantages of living in social groups
increased competition for food, mates, increased conflict, more parasites and disease.
What are the key characteristics of a desert biome: rainfall, amount of vegetation, temperature fluctuation on daily and seasonal scale, and tree type? What special adaptations have desert plants and animals developed?
extremely low precipitation, sparse vegetation, large daily temperature fluctuations, extreme heat in summer, deciduous and evergreen vegetation. adaptations include (1) succulent plants store water and exhibit CAM photosynthesis and (2) animals limit activity to moist periods and are nocturnal; animals able to store large quantities of water in their tissues.
optimal foraging theory?
foraging is compromise between costs of feedin and feeding benefits. Must be energy efficient. USed to predict foraging tendencies, but animals also consider possibility of increased predation (and may choose lower 'value' foods-compromising energy and nutrition to avoid being eaten). Optimal foraging means animals increase fitness - more efficient=more energy for reproduction, stronger healthier individuals.
What is exponential capacity for growth, when does it naturally occur, example?
exponential capacity for growth = rate of increase remains constant while the actual increase in numbers accelerates rapidly as the population size grows. typically occurs when a species expands into new habitat, e.g. introduction of bacteria into a fresh medium.
Is there a greater variety of species on land or in the ocean and why?
There is a wider variety on the land as a result of the sharper barriers between terrestrial habitats; ocean variation is less distinct and there is less variety of available niches, resulting in less evolutionary diversity.
what type of lake would have thermocline & why.
larger temperate region lakes. warm epilimnion upper layer forms at lake surface, colder hypolimnion below, thermocline between - abrupt region of change. sun penetrates top, warms top, stratifies and makes less dense this layer. colder, more dense below. warm floats on top of cold - narrow transition region or thermocline.
What are lichens, which fungal phylum is best represented here, and what is the function of each partner in the association?
Lichens are symbiotic associations between a fungus and a green alga and/or cyanobacterium. The best represented of this group is the Ascomycota. These species are not able to grow independently; the fungus directs the photosynthetic component to produce certain special metabolic substances.
Certain groups of herbivores can feed on plants protected by secondary chemical compounds. How do they do this and what are the advantages to feeding on these plants?
Some herbivores have evolved mechanisms over time that allow them to break down irritating compounds. By feeding on plants few to no other organisms eat, they are reducing outside competition on their food source.
What two classes comprise angiosperms? How are they structurally different and which derived from the other. Explain.
two classes are the monocotyledones and dicotyledones. They differ in the following ways. Monocots have parallel venation in leaves, flower parts in threes, and embryos with one cotyledon seedling leaf. Dicots have netlike venation in leaves, flower parts in fours or fives, and embryos with two cotyledon seedling leaves. Monocots are derived from dicots by the suppression of one of the cotyledons. This is evident from the fact that monocots and primitive dicots have single-pored pollen, whereas more advanced dicot pollen is three pored.
What is the difference between interspecific competition and intraspecific competition? What is gause's principle of competitive exclusion?
Interspecific competition is competition among different species. Intraspecific competition is competition among individuals of a single species. Gause's principle essentially states that no two species can occupy the same niche.
Nine characteristics of early angiosperms that are thought to contribute to their success.
flowers, gamete transfer (without requiring water), outcrossing, fruit dispersal, tough leaves, leaves with stomata, leaves with cuticles, specialized conducting elements, and production of natural insecticides.
What is carrying capacity, is it static or dynamic, and why?
Carrying capacity is the number of individuals that can be supported in a habitat indefinitely. dynamic measure, as environmental characteristics are also dynamic.
How do archaebacteria differ from eubacteria, which group is the most prominent of archaebacteria, what unique metabolism do they exhibit, what are their oxygen requirements, how do they control this themselves?
Archaebacteria differ from the eubacteria in a number of ways, most notably in the rRNA base sequences, the absence of muramic acid in their cell walls, and their often extreme habitats (anaerobic, very salty, very hot, etc.). The methanogens are the most prominent group of the Archaebacteria. Their unique metabolism allows them to synthesize methane from carbon dioxide and hydrogen, generating energy along the way. They are obligate anaerobic organisms-oxygen is literally toxic to them. They can sustain their own anaerobic environment through the reduction of elemental sulfur to hydrogen sulfide (the "rotten egg" gas).
what types of growth regulating effects are density dependent, and what types are density independent?
Density-dependent factors are those in which the resources are in short supply, causing the individuals to compete more intensely as the population grows. Density-independent factors are those caused by factors that operate regardless of population size (i.e., weather and physical disruption).
Key aspects of Taiga - seasonal temperatures? precipitation? day length? soil nutrition? species variation? how is tundra different from taiga?
long cold winters, short summers, very dry winters, greatest precipitation in summer, short days in winter, long days in summer, infertile soils, coniferous trees, limited variability of species. tundra = virtually no trees, only scrubby plants, open grassland - boggy at times, underlying layer of permafrost-ground that never thaws.
Is a small or large population more likely to become extinct, why, and how does inbreeding effect the poss. of extinction?
small population more likely to become extinct -->random events more likely to adversely affect smaller population. Inbreeding=loss of genetic vigor, loss of variability affects ability to adjust to changing conditions, increases poss. of extinction.
What are three major oceanic habitats, what distinguishes each, and what life lives in each?
three major oceanic habitats are (1) neritic zone-shallow zones along continental coasts, large number of species; (2) surface zone-upper layers of open sea - diverse species; (3) abyssal zone,deep-water areas shown to have more diversity than was thought as sampling techniques have improved.
Is the term niche synonymous with the term habitat? Why or why not, how does an organisms theoretical niche differ from its actual niche?
No. habitat is part of the niche, but only the physical part; organism's niche also includes behavior, seasonal factors, and daily patterns. Theoretical niche = potential niche if no competitors present; Actual niche is what organism occupies under natural circumstances.
Why have scientists altered their concept of a final climax vegetation in a given ecosystem? What types of organisms are often associated with early stages of succession?
Three factors have altered concept: (1) climate is continually changing; (2) succession is a slow process; and (3) the nature a region's vegetation greatly affected by human activities. Organisms often associated with early stages of succession are those that exhibit symbiotic relationships: lichens = algae + fungi; legumes = plant + bacteria; and mycorrhizae = plant + fungi.
What are morphological defenses plants use to defend themselves from herbivores, how does the nutritional suitability of a plant effect its being eaten by animals?
Defense structures include thorns, spines, prickles, sticky plant hairs, and high levels of silica. Nutritionally, if a plant lacks several of the 12 essential amino acids, it is less likely to be useful food.
What does it mean if a plant is dichogamous. Explain genetic self-incompatibility, what is the advantage to these characteristics?
Dichogamous plants are functionally staminate at one point in time and functionally pistillate at others; that is to say, the plant has both male and female parts, but they are not fertile at the same time. Genetic self-incompatibility refers to plants that cannot fertilize themselves due to incompatibility of pollen with stigma or inviability of the embryo. The advantage to this is that it promotes outcrossing, leading to more genetic diversity in the population.
What is a seed, why is it a crucial adaptation to terrestrial life, how does the seed of a gymnosperm differ from the seed of an angiosperm, and how are they similar?
A seed is a developing sporophyte in a state of arrested embryonic development surrounded by a protective coat. The seed is crucial because it protects the embryo from drying out or being eaten and provides a source of energy for the growing plant. In angiosperms, the ovule is completely surrounded by the tissue of the sporophyte; in gymnosperms the ovule is partially or totally exposed at pollination. In both plant types, male and female gametophytes develop within the sporophyte and are completely dependent upon it for nutrients and water.
What is co-evolution, give advantages and examples.
Coevolution =long-term mutual evolutionary adjustment in organism characteristics in relation to one another, e.g. fruit provides food for animals which then increase seed dispersal of the plants; pollen or nectar provides animal food and causes flower pollination.
What conditions in Abyssal zone led early biologists to believe that nothing lived there, what provides the energy for deep-sea communities around warm water vents and what kind of organisms found there?
abyssal zone appears inhospitable: intense pressure, low temperature, and complete lack of light - no photosynthesis. Sulfur-spewing hydrothermal vents provide chemoautotrophs with a metabolite (sulfur), and can support diverse community around vents, e.g. large tube worms, large clams, acorn worms, + many other unusual organisms.
What are the earths repositories for nitrogen, what is the process of nitrogen fixation, and what types of organisms fix nitrogen?
earth holds nitrogen as atmospheric nitrogen gas, fixed nitrogen in the soil, and nitrogenous compounds in organisms. Nitrogen fixation involves= converting gas to ammonia, performed by bacteria, especially those associated with legumes, and certain cyanobacteria.
Temperate deciduous forest
In areas of northern hemisphere - warm summers, cold winters, sufficient precipitation. cover much of eastern US and Canada.
What defines a symbiotic relationship, what are the three classes of symbiosis and how do they compare?
Symbiotic relationships involve two or more kinds of organisms living together in a more or less permanent situation. The classes of symbiosis are (1) commensalism, in which one organism benefits while the other neither benefits nor is harmed; (2) mutualism, in which both organisms benefit; and (3) parasitism, in which one organism benefits while the other is harmed.
What is meant by "double fertilization", what two distinctly different tissues arise from the process and what is the genetic complement and function of each?
Double fertilization occurs when one sperm nucleus fertilizes the egg and the other fuses with one of the polar nuclei. The zygote and endosperm arise from this; the zygote is diploid and grows into the embryo; the endosperm is triploid and supplies nutritive tissue for the embryo.
What is demography, what two factors are taken into accoun, and what are the characteristics of a stable population?
Demography is the statistical study of populations, which involves predicting the ways in which populations will change in the future. The two factors taken into account in demographic studies are age distribution of the population and changing population size through time. The characteristics of a stable population are births plus immigration equals deaths plus emigration, and population size and age structure remain constant.
Key characteristics of temperate grasslands - productivity? seasonal temperature? rainfall? how do they resemble savanahs?
extremely rich soil, long cold winters, and relatively abundant rainfall. resemble savannas = large quantities of perennial grasses which support herds of large grazing mammals.
What happens to an organisms niche when it newly occupies habitat lacking other organisms? what happens to niches of evolving species in terms of competitive exclusion?
Under these circumstances, the niche widens. If the species become different enough to have different niches, there is no exclusion; if they are not different enough, additional selection will occur or one will become excluded.
What is the effect of deforestation on the water cycle and flood control? What is its effect on the nutrient cycles and overall fertility of land?
Deforestation produces fewer plants, which results in greater water runoff and increased land damage due to flooding. With regard to the nutrient cycles and overall fertility of the land, with increased water runoff, greater amounts of nutrients are lost from the immediate environment and fertility is decreased.
Compare and contrast K strategists with r strategists. What type of growth curve dot hey exhibit, what limits the growth of the populations, when in their lifespan do they reproduce? what is the relative generation time, number and size of offspring? To
K strategist exhibits a sigmoid growth curve, and the limiting factor is K, the carrying capacity. These types of organisms reproduce late and have long generation times. They have few, large offspring and provide lengthy parental care; their offspring mature slowly. An r strategist exhibits an exponential growth curve, and the limiting factor is r, the intrinsic rate of increase. These types reproduce early and have short generation times. They have many, small offspring and provide little parental care; their offspring mature rapidly.
Characteristic of temperate grassland and where
cover large areas in interior of north america, also in eurasia and south america. With sufficient precipitation, very good for agriculture. Common in our prairies.
What is denitrification, what organisms carry it out and what would happen if all the organisms that do it, died?
Denitrification is the conversion of nitrate to nitrogen gas and nitrous oxide. The process is carried out by several different genera of bacteria, and serves an important role, because without it occurring, all nitrogen would become fixed and ultimately washed out to sea, unavailable for use by the different ecosystems.
why is the kingdom protista said to be an artificial group, how is it different from other kingdoms?
Protista have been grouped together for convenience, rather than grouped together because of evolutionary relationships to one another.
What are the benefits and costs of territorial behaviour, and when is it disadvantageous?
territory is an area which is used exclusively by one animal or social group and is actively defended against intrusion by others. Animals are territorial when the benefits of exclusive use of resources in a territory outweigh the costs of defense and risk of injury or predation.
Whats the difference between asymmetry, radial symmetry, and bilateral symmetry? Which groups of animals display which kinds of symmetry? What are the advantages of being bilaterally symmetrical?
asymmetrical animal has no recognizable symmetry, except perhaps by chance; this lack of symmetry is characteristic of the sponges. Radially symmetrical animals can be bisected in any direction within a single plane, and includes the jellyfishes and ctenophores. Bilaterally symmetrical animals comprise the rest of the invertebrates and invertebrates and can be bisected only in one plane along a single axis, producing two equal halves. Bilateral symmetry allows for cephalization-a concentration of sensory organs at the anterior end of the animal.
How are biomass and productivity related to successional stage of an ecosystem? How is the # of species, esp. heterotrophs, related to successional stage of ecosystem and why?
Biomass and productivity are related to the successional age of an ecosystem in that older ecosystems have greater biomass, but lower net productivity. There are more species in mature ecosystems, and especially many more heterotrophic species in mature ecosystems. This results because mature ecosystems better regulate their nutrient cycles and generally have more specialized organisms.
Why does natural selection favour mate choice, and what factor is most important in determining which sex exhibits mate choice according to Trivers?
Mate choice can be adaptive if individuals in a breeding population differ in the quality of their genes of resources they hold. The advantages of mate choice include selecting parasite-free individuals (a trait which may be heritable) or acquiring food or nest sites needed for reproduction. Trivers' observation was that parental investment would be the most important quality to look for in mate selection.
What are the characteristics of a primitive angiosperm flower? How can scientists determine whether a flower is primitive or advanced?
primitive angiosperm flower has numerous, free, spirally arranged sepals, petals, stamens, and carpels, with little visual differentiation between petals and sepals. Scientists can determine whether a flower is primitive or advanced by comparing the wood and pollen of the plant to those of known primitive plants, observing fusion and/or reduction in flower parts, and comparing the flower to fossil flowers.
What is reciprocal altruism, what is kin selection, and how does kin selection increase inclusive fitness?
Reciprocal altruism is when individuals perform an act of altruism in expectation that they will receive similar treatment from others. Altruistic behavior is that which is not in the individual's self-interest. Kin selection maximizes one's inclusive fitness if by sacrificing one's self for one's relatives his total gene contribution to the next generation increases. Inclusive fitness refers to the total number of one's genes that are passed on to the next generation. Kin selection can lead to altruistic behavior when the individuals in a society are related to one another.
What characteristics distinguish animals from other organisms? What is the structural nature of animal cells that differentiates them from plant cells?
Animals are multicellular heterotrophs that digest their food internally. This distinguishes them from the other kingdoms of living organisms. Animal cells are distinct from plant cells in that they do not have cellulose-containing cell walls.
What is behavioural ecology and how do behavioural ecologists assess adaptive significance of behaviour?
study of the adaptive significance of behavior: measures the adaptiveness of behavior by estimating fitness (reproductive success). Fitness can be estimated from the effect behavior has on survival, or some measure of reproduction such as the number of matings an individual has, the benefits and costs of the behavior, or the number of offspring produced.
What is the principle difference between gymnosperms and angiosperms? Is fertilization in angiosperms direct or indirect? Why? From what part of the flower does angiosperm fruit develop?
Angiosperms differ because they contain ovules enclosed within carpels, the parent sporophytic tissue. Fertilization is indirect. Fertilization is indirect because the ovules are enclosed within an ovary, and can only be accessed by a pollen tube generated by the pollen grain. The angiosperm fruit develops from the carpel.
What is the lateral line system in fish and how does it function?
The lateral line system is the ability to detect changes in the pressure of water and sense movements of objects. Pressure waves created by objects moving in the surrounding water deflect cilia on hair cells that send positional information to the brain.
Why must flowers pollinated by birds produce greater amounts of nectar than those pollinated by most kinds of insects? How do such plants deter insects from wasting their nectar?
Plants pollinated by birds must produce more nectar because birds use a lot more energy than insects. Deterring factors are red flowers, which attract birds but are not especially noticeable to insects; odorless flowers, because birds have strong visual, but weak, olfactory senses; and well-protected nectaries, which are available only to a strong beak.
What is one advantage of possessing jaws, from what structure did jaws evolve and what is the evolutionary derivation of teeth as found in jawed mammals?
An advantage to possessing jaws is that it encourages active predation; it also improves the ability to collect food over sucking or filtering it. Jaws are a modification of one or more gill arches. Teeth are modified from skin.
Characteristics of Tundra biome & where?
about 20% of earths land surface, open grassland, boggin in summer, over layer of permafrost - in arctic and mountain zone (alpine) regions.
What are three primary characteristics of chordates and give an example.
single, hollow dorsal nerve cord; a dorsal notochord; and pharyngeal gill slits. The three subphyla are Urochordata (tunicates), Cephalochordata (lancelets), and Vertebrata (vertebrates).
How efficient is energy transfer from one trophic level to the next? What type of diet - carnivorous or herbivorous provides more food value to given living organisms and why? Is it more efficient to feed starving people corn, or hamburgers?
10% of the energy is transferred from one trophic level to the next. Herbivorous diets provide the greatest food value to living organisms because they involve eating the primary producer on the first trophic level rather than a primary or secondary consumer, which is a higher trophic level; therefore less energy is lost going from one trophic level to the next. The more efficient method would be to feed them corn.
What is the difference between an acoelomate, a pseudocoelomate, and a coelomate animal? What advantages does a coelomate animal have over acoelomate or pseudocoelomate animals?
acoelomate animal possesses no coelom (body cavity). A pseudocoelomate animal possesses no internal space between its gut and its external musculature. A coelomate animal possesses a true body cavity between the external surface of the gut and the internal surface of the body wall, in which many of the organs are suspended by connective tissues. Coelomates have as an advantage over pseudocoelomates and acoelomates the potential space for digestive tracts that are longer than their own body lengths, permitting a wider range of feeding strategy, as well as internal spaces for the development and storage of gametes.
What are mycorrhizae, what is the difference between endomycorrhizae and ectomycorrhizae, which fungi are most prominent in each and what is the function of each partner in the association?
Mycorrhizae are fungi that live in association with plant roots. Endomycorrhizae hyphae penetrate the outer cells of the plant root, whereas ectomycorrhizae surround but do not penetrate the roots. The most prominent mycorrhizal fungi are the Zygomycota. The plant supplies food to the fungi, while the fungi serve as extensions of root surface area, allowing the roots of the plant to better absorb materials from the soil.
What is the primary disadvantage of a bony skeletone compared to one of cartilage, what structure do most fish have to counter this and what is the evolutionary derivation of it?
The bony skeleton weighs more so that fish tend to sink with it. An air bladder provides buoyancy to counter the sinking. This bladder developed from a lunglike outpocketing of the pharynx.
What characteristics are shared by green algae and plants? How do the details of cell division in both groups compare, how does this contrast with animal cells?
Green algae and plants share chlorophylls a and b, carotenoids, cellulose cell walls, and starch as a food storage product. Both groups have cellular division characterized by the development of a cell plate between the daughter cells (animal cells divide by pinching in half).
What type of digestive system do most insects possess? What digestive adaptations occur in those insects that feed on juices low in protein and why? What respiratory adaptations have occurred in some insects?
Most insects possess a tubular digestive tract that is somewhat coiled. Insects that feed on juices low in protein have a greatly coiled tract to provide greater opportunity to absorb nutrients and to allow their digestive enzymes, which are weaker, more length over which to work. Respiratory adaptations in insects include (1) tracheae enlarged to form air sacs surrounded by muscles that help force air deep into the body, (2) permanently closed spiracles, and (3) gases that cross between the trachea and exoskeleton via diffusion.
HOw is the phosphorous cycle different from the water, carbon, nitrogen and oxygen cycles & what are the natural sources of phosphorous?
phosphorus exists in mineral form rather than in the atmosphere, as in the other cycles. The natural sources for phosphorus are soil (small amounts), isolated rock outcroppings, ocean sediments, guano, and bone meal.
What are major evolutionary innovations among cnidarians as compared with sponges? Why are they important?
Cnidarians have a tissue level of organization, whereas sponges do not. Tissue-level organization allows for greater coordination within an animal.
Characteristics of Taiga (boreal forest) biome - along Eurasia and North America
vast coniferous forest, long winters, cold winters, but plants grow rapidly during long summer days - characteristic of much of BC
What is sexual selection and how does it differ from natural selection?
Sexual selection is the process by which individuals compete for access to mates; it involves competition among members of one sex for mates, and mate choice. Natural selection concerns the evolution of traits favoring survival; sexual selection concerns the evolution of traits that favor mating success.
Explain the difference between determinate and indeterminate growth in plants. What parts of the plant exhibit each type of growth?
Tissues that exhibit determinate growth (such as the apical meristem) do not continue to grow once a structure (i.e., a flower) is formed. Tissues with indeterminate growth (such as leafy shoots) continue to grow and differentiate.
What type of circulatory system do arthropods have? Describe the direction of blood flow - what helps to maintain this flow?
The arthropod circulatory system is an open one, with a dorsal, longitudinal heart. The blood flows from anterior end to the head, through internal body spaces toward the posterior end and back in the dorsal vessel. This one-way flow is maintained by valves in the posterior region of the heart.
What is an androecium, which flower parts is it comprised, what is the evolution of these flower parts and what structure produces the pollen grains?
An androecium is the male reproductive structure, and it is composed of the stamens, which have probably evolved from the systems of small branches among which the microsporangia were borne. The anther produces pollen grains.
What are the five key characteristics of amphibians and what is the primary differentiating characteristic of each order of amphibian?
Modern amphibians are characterized by the presence of legs, cutaneous respiration, lungs, pulmonary veins, and a partially-divided heart. Salamanders and newts have tails; frogs and toads lack tails as adults; and caecilians lack legs.
What proportion of the earths surface is covered by fresh water. Describe three zones of fresh water lakes and ponds.
Almost 2% of the earth's water is fresh. (1) littoral zone-shallow water along the edges; (2) limnetic zone-upper layer of open water; and (3) profundal zone-water below the limit of light penetration.
Which arthropod organ system transports oxygen throughout the body? In what way is this different from the vertebrates? What is the resultant evolutionary impact? Describe the respiratory system of a typical arthropod.
The respiratory system transports oxygen throughout the arthropod's body. This is different from vertebrates in that vertebrates use the circulatory system. The resultant impact is a limitation of the size of the organism, with each cell necessarily within diffusion distance of a respiratory structure in the arthropod. The respiratory system of a typical arthropod is numerous, small, branched, cuticle-lined air ducts called tracheoles with an opening to the outside via spiracles that can be closed to reduce water loss.
What evolutionary advantages does segmentation confer upon an organism?
Segmentation allows for greater evolutionary potential and flexibility. Segments can be duplicated or modified into specialized regions of the body.
What are the advantages of an exoskeleton? What occurs during the process of ecdysis? What controls the process?
exoskeleton provides a surface for the muscles to work against, protects against predators and injury, and reduces water loss. During ecdysis a new exoskeleton is grown under the old one, with fluid separating them; then the outer skeleton is shed and the body is expanded by blood circulation and air intake, and the soft new skeleton hardens as it is exposed to air or water. The control for this process involves hormones.
What is the difference between plankton and nekton in surface zone? How important are photosynthetic plankton to survival of earth? Is turnover of nutrients in surface zone slow or fast?
Plankton =microscopic organisms, algae, and cyanobacteria. Nekton = fish and other larger organisms that feed on the plankton. photosynthetic plankton =important: 40%+ of earth's photosynthesis occurs in plankton. rapid turnover of nutrients in the surface zone; most nutrients tied up in organisms.
What two processes have led to adaptive change during the course of human evolution? How can one estimate the relative contributions of these processes to the evolution of human behaviour?
Biological and cultural evolution have led to adaptive change in human evolution. Studying human behavior across several cultures can give indications of the relative contributions of these processes.
Why are most deserts 30 degrees north and south of equator, will deserts more likely be in interior, or at edge of continent, why? why is windward side of a mountian more moist than leeward side?
deserts located at 30 degree latitudes because the air is falling and being warmed; warm air holds more moisture than cool air, there is less precipitation. more likely that desert will form at interior of continent distance from the sea. windward side of mountain moister because air rises on this side, is cooled and loses its moisture-holding capacity, causing precipitation. On the leeward side the air descends, is warmed, and holds more moisture, blocking precipitation.
Define monogamy, polygyny and polyandry. In birds, how does the amount of parental care required by the offspring affect the evolution of a species mating system?
Monogamy is a mating system in which a male and female form a pair bond during a breeding season. Polygyny occurs when a male mates with more than one female, and polyandry occurs when a female mates with more than one male. The more care the offspring require, the more likely the (bird) animals will pair monogamously.
What are key characteristics of tropical rain forests: # of species, level of speciation, amount of rainfall, amount of nutrients in soil, and location of nutrient concentration? Why is slash and burn agriculture so harmful to tropical rainforests?
The key characteristics are a great variety of species, highly specialized, tremendous rainfall, poor soil nutrition, and most nutrients in living organisms-especially the trees. Slash-and-burn agriculture is damaging because burning destroys the nutrients rather than putting them back in the soil.
Into what funtional units are cells organized? What are collections of these units called? What are the simplest animals to have these?
Cells are organized into functional units called tissues, which aggregate to form organs. The simplest group in which organ level of development is seen is the Platyhelminthes.
what is the probably origin of eukaryotic mitochondria, was this a single or multiple event, why, and do all eukaryotes possess mitochondria?
Eukaryotic mitochondria are probably derived from symbiotic nonsulfur purple bacteria, apparently in a single event because all mitochondria are the same. All eukaryotes but Pelomyxa and a few other groups possess mitochondria.
What are maphighian tubules, how do they work, what system are they connected to, how are wastes processed by them and how is water loss regulated?
Malpighian tubules are projections from the digestive tract, between the midgut and the hindgut. The wastes are processed as follows: fluid is absorbed from the blood through the walls of the Malpighian tubules, nitrogenous wastes are concentrated, then they are emptied into the hindgut and eliminated. Water loss is regulated because water and salts are reabsorbed by the hindgut and returned to the circulation.
How are nutrients and oxygen supplied to three freshwater zones, and are they constant in zones all year?
Organic and inorganic nutrients are supplied to lakes chiefly from the terrestrial environments. Rain, of course, adds to lakes, and oxygen can also diffuse directly through the surface. "Nutrient richness" of healthy lake systems tends to be cyclical, being greatest in the thermal-induced fall and spring overturns.
What were the five major innovations allowing amphibians to invade land and why was each important?
(1) Legs were necessary to support the body's weight. (2) Lungs were necessary because the delicate structure of fish gills requires the buoyancy of water to support it. (3) The heart had to deliver greater amounts of oxygen required by walking muscles. (4) Reproduction had to be carried out in water, until ways could be found to prevent the eggs from drying out. (5) Techniques had to be developed to prevent the body from dessication.
What is the evolutionary significance of chlorophyta? Why is chlamydomonas an important member and what determines whether a collection of individuals is truly multicellular?
Chlorophyta include the ancestors of the plants and are therefore significant in evolution. Chlamydomonas is an important member of this phylum because many other simple green algae resemble it, but may lack flagella; other colonial green algae like Volvox appear similar to colonies of Chlamydomonas-like cells. A collection of individuals is truly multicellular if there is a division of labor among the cells so that certain of them perform very specialized functions.
What is the significance of the jointed appendage? Which groups have jointed appendages?
Jointed appendages confer a great degree of motility upon an animal. Arthropods and chordates possess jointed appendages.
What are pistillate versus staminate flowers, what is a dioecious versus a momcious plant? What is the advantage of each of these characteristics?
Pistillate flowers have only pistils and sterile or no stamens; staminate flowers have only stamens and no carpels. A dioecious sporophyte produces either ovules or pollen, whereas a monoecious sporophyte produces both ovules and pollen. These diverse characteristics promote outcrossing and reduce inbreeding.
What makes an animal a eumatazoan? What are the three distinct tissuelayers that form in a eumatazoan?
Eumetazoans possess three tissue layers: ectoderm, mesoderm, and endoderm.
seven ways that prokaryotes different from eukaryotes
(1) multicellularity: bacteria are not multicellular; (2) cell size: bacteria are very small; (3) chromosomes: bacteria lack a nucleus and DNA is not complexed with proteins; (4) cell division and genetic recombination: bacteria do not have true sexual reproduction, but can transfer genetic material; (5) internal compartmentalization: bacteria lack membrane-bound organelles; (6) flagella: bacterial flagella are composed of single fibers of flagellin; (7) autotrophic diversity: bacteria have different kinds of aerobic and anaerobic photosynthesis & variety of end products, e.g. sulfur, sulfates, and oxygen; other bacteria are chemosynthesizers, metabolizing various inorganic and organic compounds.
In the evolution of the animal body, what are eight significant evolutionary milestones? List an animal phylum that characterizes each milestone.
The evolutionary milestones in animal body plan evolution are multicellularity (sponges); tissues (cnidarians); organs (flatworms); body cavity (roundworms); segmentation (annelids); jointed appendages (arthropods); deuterostomic development (echinoderms); and development of the notochord (chordates).
What is the structure of a bacterial cell wall, how does it differ between gram +, gram- bacteria. Which type of bacteria more resistant to action of antibiotics and why?
bacterial cell wall is a network of polysaccharide molecules cross-linked by polypeptides. Gram-positive bacteria have a plain polypeptide-linked polysaccharide wall, whereas gram-negative bacteria have an additional layer of large lipopolysaccharide molecules deposited over a plain layer. Gram-negative bacteria are generally more resistant to most antibiotics because of the nature of the cell wall.
What are seven classes of vertebrates and give examples.
seven classes of vertebrates are as follows: Agnatha (lampreys, hagfishes), Chondrichthyes (sharks, rays, skates), Osteichthyes (bony fish), Amphibia (frogs, toads, salamanders), Reptilia (reptiles), Aves (birds), Mammalia (mammals).
Why does mutation play such an important role in creating genetic diversity of bacteria? How does bacterial recombination result in genetic diversity in bacteria, what is an example of effects of such variability?
Mutation is important because with rapid generation time, populations can double within several minutes, allowing a favorable mutation to be represented in large numbers quickly. Bacterial recombination results in genetic diversity because genes are transferred from one bacterium to another via viruses, plasmids, or other DNA fragments. An example of such variability is the development of antibiotic resistance.
What are three fundamental characteristics of reptiles, what are three other important characteristics, and give an example.
Modern reptiles are characterized by the presence of amniotic eggs, dry skin (covered with scales), and thoracic breathing. Reptiles also have internal fertilization, a partially divided ventricle in the heart, and are cold-blooded. The four living orders of reptiles are the Chelonia (turtles and tortoises), the Rhynchocephalia (tuataras), the Squamata (lizards and snakes), and the Crocodilia (crocodiles and alligators).
What is the primary difference between vertebrate and invertebrate animals? Which group is has more representative species populus?
Vertebrates possess a backbone-a dorsal vertebral column enclosing a dorsal hollow nerve cord. Invertebrates do not, yet they are by far more numerous than the vertebrates, containing among them all the arthropod and molluscan phyla, among others.
What is the relationship between notochord and the vertebral column in vertebrates, how is the latter structure associated with the nerve chord?
In the vertebrates, bony vertebrae replace the notochord. The nerve cord is protected within a U-shaped groove in the vertebrae.
What are the primary characteristics of wind pollinated plants? Do most wind-pollinated plants have separate pistillate and staminate flowers, or do they have flowers with both parts functional? Why?
Wind-pollinated flowers are small, greenish, and odorless; have reduced or absent corollas; and hang downward in tassels that wave in the wind. These plants have separate flowers, often even on separate plants. This promotes outcrossing.
In vertebrate societies, what are teh costs to an individual who makes an alarm call? Based on ground squirrel research, which individuals are most likely to make the calls and what benefits do they receive by doing so?
An individual who sounds an alarm call is drawing attention, and therefore, usually danger, to him/herself. Females with relatives nearby tend to be the squirrels that give alarm calls, thereby protecting a large quantity of genetic material they share with their sisters and their offspring, even if the female herself is attacked.
Why are sponges considered one of the most primitive groups of animals, what kind of ancestor did sponges probably evolve from and why?
Sponges can be put through a sieve and reduced to single cells, which will then reaggregate to form a new individual. Sponges evolved from the choanoflagellate protists, as evidenced by the presence of choanoflagellate-like cells (choanocytes) in the body of the sponge.
What type of symmetry and body plan is exhibited by adult echinoderms, what is the composition and location of their skeleton, how centralized is their nervous system, what is the nature of their vascular system and how are tube feet specialized for func
symmetry is radial and there is a five-part body plan in adult echinoderms. The skeleton is calcium-rich plates called ossicles that make up the internal skeleton covered by epidermis beset with numerous spines. Their nervous system is not centralized, with no head or brain, but rather the system is composed of central nerve rings that branch. The water vascular system is a ring canal with five radial canals so that water enters through the madreporite, flows to the ring canal through the stone canal, and ultimately into tube feet. They extend and contract their tube feet through the contraction of muscular ampullae at the base of each tube foot, which forces fluid into the tube foot, causing it to extend; then when the muscles contract, fluid is forced back into the ampulla. In sea cucumbers, sea lilies, and brittle stars the tube feet are specialized for feeding.
What does optimal foraging theory predict about an animals foraging behaviour, what unrelated factors may also influence foraging?
natural selection favors foraging behavior that maximizes the net energy gained from feeding on a given food item. theory may be influence by fact that some animals are in search of specific nutrients or attempt to avoid predation.
Why are flatworms bodies so thin? Why can roundworms be fatter?
Flatworms are thin because they have no body cavity through which gases can diffuse; gas transport must occur through the skin, so the organism cannot attain great thicknesses or oxygen will not reach all of the tissues. With the roundworms came the advent of a body cavity, permitting some degree of internal circulation of gases.
What is an instar as it relates to insect metamorphosis, what are two kinds of metamorphosis in insects, how are they different and what are the immature forms of each type called?
An instar in this context refers to stages between molts. The two different kinds of metamorphosis are simple-if wings are present, they develop externally during juvenile stages with no resting stage before the last molt into adulthood (immature stages-nymphs); and complete-wings develop internally during the juvenile stages and appear only during the resting stage prior to the adult (immature stages-larvae; resting stage-pupa or chrysalis).
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