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Aboral surfaces are surfaces away from or opposite the mouth. It is also the opposite of oral which is the end containing the mouth of a radially symm. animal.
(1) oral= mouth side (bottom)
(2) aboral= opposite "w/o mouth"
- Segmentation: each segment repeats all the way down the worm. It is a very efficient design. Besides it provides for regional specialization.
- Setae: chitinous bristles
- Annelid head: prostomium & peristomium
Annelid excreation and nephridia
nephridia segmentally arranged
Structures derived from a common ancestor or same evolutionary or developmental origin
The fundamental difference between males and females is determinedby the differences in the size and function of their gametes: male gametes aresperm that only contain genes and are mobile, whereas female gametes are eggsthat contain genes, resources, and are immobile. Males are therefore more competitivethan females in most cases to find a sexual mate, since there are fewer femalegametes made than males. There is a lower chance that a male will get to matethan the chance of that of a female mating.
An obvious byproduct of this reproductive success is the outcome ofa higher percentage of the population that possesses the original trait ofsuperior sexual attraction. One of the most common examples set forth is thatof the male peacock, who has developed a complex and attractive plumage formale attraction, even at the expense of hindering movement by the massiveplumage.
Females would like to mate with the male who is good at survival.The best evidence is old age, meaning they prefer to mate with the oldestmales. The older the individual, the more it proves that they are good atsurviving. Frogs prefer males with the deepest croaks and mockingbirds prefermales that sing the most different songs.
The orange spots on guppies are made of carotene; a chemical foundin plants that the guppies eat. So, the guppies with more orange are betterforagers.
Because female gametes are “costly” to make, on few are made, andfemale reproductive success is limited by the amount of resources females haveto make babies or care for them after they are born. So, male reproductivesuccess is “mate limited,” meaning they are limited by the females’ choosiness(their “mates”).
One of the most telling behaviors in humans of sexual selectioncomes from the pheromone experiment (t-shirt experiment), which implies thatthere is a chemical component to the way humans chooses their mates. Also thelevels of attractiveness that come from symmetry explain how humans are wiredto find the most “fit” mate which is implied from the symmetry of men’s andwomen’s faces (an indication of health/fitness).
a hungry vampire bat solicits food from a potential donor, first by grooming around thestomach area and then licking the donor's face. The donor bat thenresponds by regurgitating blood if receptive.
The math required for groupselection does not work out, because the math of natural selection does notallow organisms to artificially reduce their fitness for the “good of thespecies.” Natural selection works on the survivability of individuals and theirtraits in a population, not the survivability and traits of the group as awhole.
Exponential growth is an unrealisticpatter for most species because there is a limited amount of resources, sothere will never be enough food or other resources necessary for survival tosupport an exponentially growing population.
Carrying capacity (k) is thepopulation size at which the population growth rate equals 0. This means thatthere is a peak that the population reaches, at which the population stopsgrowing and it levels off. This is due to competition and lack of abundantresources needed to support an exponential growth situation in a population.
The S-shaped curvecomes from the decrease in dN/dt as time progresses, after the populationgrowth rate has hit its peak. The rate at which the population grows willincrease to a point, and then it will decrease until the population levels offat the carrying capacity (k). This is seen in the application of biology whennatural selection acts on a population to stabilize the population size,because the resources become limited as the competition increases with a largerpopulation.
Competition is an interaction betweenspecies or organisms, in which the fitness of one is lowered by the presence ofanother. Limited supply of at least on resource (food, water, territory, etc.)used by both is required.
Exploitative competition is the mostcommon type of competition and it is the simple act of one organism consumingor using a resource before another competitive force/organism uses it.
Interactions betweenorganisms can vary over time because the environment will change over time. Theenvironment can change any time and can greatly affect one or both of thepopulations in a certain study of community interactions. Especially in desert environments, wherethe environment is greatly varied from hour-to-hour, day-to-day, andseason-to-season (with humidity, temperature, etc), there are other factorsbesides interspecific competitive interactions.
The world iscomplicated because there are an infinite amount of different paths theenvironment can take and that can have an infinite amount of possibilities onthe interactions between species in a community and amongst species in apopulation. The world is complicated because even after 50 year studies ofcertain communities or ecological regions, scientists may still have no idea orvery little of an idea as to what long-term responses of an ecosystem tofluctuations in the environment actually look like.
Fungi can take the nitrogen fromdead organisms and turn it in to nitrogen used by the rainforest. In deserts,the bodies stay there for much longer, because the environment is not assuitable to fungi, which are the primary decomposers.
This is an anthropomorphized view ofthis subject. Genes that code for traits that get passed on more (becausetraits survive and reproduce well), by the mathematics of it, become morecommon in the population in future generations in the gene pool.
The distancebetween the crests of electromagnetic waves is called the wavelength.Wavelengths range from less than a nanometer (gamma rays) to more than akilometer (radio waves). The entire range of radiation is known as theelectromagnetic spectrum. The higher the energy, the shorter the wavelength,and the longer the wavelength, the lower the energy. The segment most importantto life is the band from 380 nm to 750 nm. This is visible light.
This reaction ofphotosynthesis occur in the thylakoid of the chloroplast because that is wherethe pigments are contained that can absorb and harvest the light energy fromthe sun, transferring it to excite electrons. More specifically, thesereactions happen in the thylakoid membrane and build up an H+ (proton) gradientinside of the thylakoid space, helping to drive the phosphorylation of ATP bythe diffusion of protons through ATP synthase.
Cyclic electron flow(photosystem I) involves energy released from the capturing of the photon, tothe active transport of hydrogen ions from the stroma to the thylakoid space,resulting in a concentration gradient, which results in chemiosmosis and theproduction of ATP (result of chemiosmosis- process of converting ADP to ATP).The electrons return to the reaction center.
The energetic resultof cyclic flow is that the potential energy in electrons is transformed topotential energy stored in ATP.
The energetic resultof noncyclic electron flow is that energy from two photons of light isconverted into the potential energy in ATP and NADPH. Water is broken down torelease H+ and O2.
The potential energyin the ATP and NADPH produced during the light dependent reactions ofphotosynthesis can only be stored for a fraction of a second, thus this energymust be used immediately or the energy will be lost.
(C3) The Calvin Cycleincorporates each CO2 molecule, one at a time, by attaching it to afive-carbon sugar named ribulose biphosphate (RuBP). The product of thereaction, catalyzed by the enzyme rubisco, is a six-carbon intermediate sounstable that it immediately splits in half, forming two molecules of3-phosphateglycerate (for each CO2 fixed).
The adaptive basisof leaf structure came about due to the evolution of terrestrial plants.Because there isn’t as much moisture on land as there is for aquatic plants (obviously),the cuticle, stomata, vascular structures, and palisade cells are all examplesof how these plants have adapted to life on land, since they all act to makephotosynthesis the most efficient it can be (keep in water, preventdesiccation, regulate gas flow, etc.).
All plants do notuse CAM photosynthesis because not all plants need that adaptation. Not allplants live in arid environments; actually, most of them live in more moistenvironments.
Carbon dioxide + RuBP--> PGA
This carbon fixation occurs at night,through the open stomata, and is stored until morning when the light reactionscan use the CO2 and light energy to make glucose.
Carbon dioxide--> malate
An organism that undergoesphotosynthesis and cellular respiration that contains cell walls in theircells, chloroplasts; and plants are multicellular organisms that typicallyproduce their own food from inorganic matter by the process of photosynthesis.The cell walls contain cellulose for structure, and the organisms also containvascular systems, xylem and phloem.
Mosses are forced to besmall since they lack vascular tissue. They are thus forced to live in moistenvironments to avoid desiccation, to best pick up nutrients, and for theirswimming sperm to survive long enough to get to the egg in the archegonia.
When the swamps of the Carboniferous era began to dry up, theseedless vascular plants began to perish, and the primitive seed plants beganto rise to dominance. As in nonvascularplants, though, the sperm of ferns and all other seedless vascular plants areflagellated and swim through a film of water to reach eggs. In part because ofthese swimming sperm, seedless vascular plants today are most common in dampenvironments, which limits their geographic distribution.
They are most successful because their various modes of seed dispersal (including attraction of various other organisms that aid in dispersal) and because they have the most efficient and “sure” mode of reproduction.
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