C = Decrease, No Effect, No effect, Increase, Increase:
According to Figure 2, in the presence of wolves [white bars], the proportion of time spent on rest is less, the proportion of time spent feeding on carcasses is more, and the proportion of time spent on vigilance is more than in the absence of wolves [gray bars]. Although the mean proportion of time spent on travel increases in the presence of wolves, the error bars overlap, showing that the difference is not statistically significant.
A = The population will be 3,845 after a year. The bison will not pose a problem until the following year, and no conservation action will need to take place:
dN/dt=rmaxN[[K−N]/K] should be used to determine the one-year change in population size: 0.28×3,652[[4,500−3,652]/4,500]=193. Adding 193 to 3,652 projects a population of 3,845, so the population will not reach the point at which bison migration occurs. However, it will reach a level to initiate migration the following year.
Climate change can affect oceanic ecosystems and their food webs. In the East China Sea [ECS], three major climactic events were considered:the Pacific Decadal Oscillation [PDO],the East Asia winter monsoon [EAWM], andthe El Niño Southern Oscillation.Figure 1 shows the relationships among these climactic events, surface sea temperature [SST], amount of phytoplankton, and copepod abundance. Copepods are important primary consumers in this ecosystem, and many species of fish depend on copepods as a food source. Solid arrows on the diagram indicate a statistically significant effect. The thicker the arrow, the greater the effect. Dashed arrows indicate statistically insignificant relationships.Figure 1. Structural equation model deciphering interactions among climate, phytoplankton, and copepods in the southern East China Sea. Solid arrows indicate significant effects, with the thickness of the arrow reflecting the relative effect. Dashed arrows indicate inconsequential effects.
What do the data in Figure 1 suggest about a null hypothesis that the East China Sea ecosystem is unaffected by climactic events?
Sea otters living along the Pacific coast were hunted to near extinction in the nineteenth century. After being protected from hunting in the early 1900s, a remnant population of otters near Adak Island, Alaska, recovered rapidly. Otters did not return to the environmentally similar nearby island, Alaid Island. Sea otters eat sea urchins, which eat kelp, a brown alga. Researchers surveyed both islands in 1988, to measure sea urchin biomass and kelp density. The data are presented in Table 1.In 1991, researchers at Adak Island observed the first attack by a killer whale on a sea otter in historical times. The researchers hypothesized that the population sizes of the larger marine mammals that the killer whales normally prey on declined, so the killer whales were starting to prey on different prey, including the smaller sea otters.
Which of the following best predicts the effects of an increase in killer whale predation on sea otters on the Adak Island ecosystem?
Baker's yeast, Saccharomycetes cerevisiae, is the species of yeast that is commonly used in baking, brewing, and making wine. It is a single-celled organism; each cell is capable of undergoing asexual reproduction by mitosis and sexual reproduction by meiosis, forming spores that combine with other spores.To find out if energy and nutritional resource availability determines which form of reproduction is used, researchers grew twenty yeast colonies on an agar medium plate providing ideal nutrient environments. Each colony was composed of a population of yeast that originated from a single yeast cell that had reproduced asexually to form a population of millions of yeast clones. That plate was used to produce replicate plates of yeast colonies. Each replicate plate was a mirror image of the original cultures, so each colony could be subjected to each treatment group. The replicate plates contained different media as follows.Robust media: Contains all nutrients required by yeast in excess amountsComplete media: Contains all nutrients at a level promoting exponential growth at rmaxMinimal media: Nutrients available at a low level, allowing growth, but stressing the yeast coloniesDeficient media: Nutrient content less than what is needed to sustain growth, extreme stress on yeast coloniesEight replica plates were made, two plates of each media, and all plates were incubated at 30°C for 24 hours. Yeast from each colony were observed through a microscope and their means of reproduction determined. Table 1 summarizes these results.
Which of the following best explains the data in Table 1 ?
function- cover body and line organs, serves as barrier ag pathogens and fluid loss
locations- nasal passage, kidneys, glands, intestines, skin, respt tract, anus, mouth, vagina
ex: squamous, flat short thin, leaky, exchange by diffusion [lin of blood vessels or air sacs in lungs]
cuboidal- dice shaped, secretion, [glands, kidney tubules]
columnar- tall large, secretion and absorption, [linings of intestines]
What do the data in Figure 1 suggest about a null hypothesis that the East China Sea ecosystem is unaffected by climactic events? A - The null hypothesis is rejected since there are significant effects of EAWM and PDO on surface sea temperature and copepod abundance.
Which of the following includes the most likely change in the coloration of the beetle population after pollution and a correct rationale for the change? The coloration range shifted toward more light-colored beetles, as in diagram I.
Which of the following best predicts the results of a drought in the savanna research area with regards to community resilience to this environmental change? The lightly grazed area is likely to recover more quickly from the drought due to greater biodiversity.
Which of the following best predicts the effects of an increase in killer whale predation on sea otters on the Adak Island ecosystem? The sea urchin population will increase and the kelp population will decrease, leading to reduced total biomass and diversity in the Adak Island ecosystem.