Answer:
Explanation:
Food webs describe the relationships — links or connections — among species in an ecosystem, but the relationships vary in their importance to energy flow and dynamics of species populations. Some trophic relationships are more important than others in dictating how energy flows through ecosystems. Some connections are more influential on species population change. Based on different ways in which species influence one another, Robert Paine proposed three types of food webs based on the species of a rocky intertidal zone on the coast of Washington (Ricklefs 2008, Figure 2). Connectedness webs (or topological food webs) emphasize feeding relationships among species, portrayed as links in a food web (Paine 1980). Energy flow webs quantify energy flow from one species to another. Thickness of an arrow reflects the strength of the relationship. Functional webs (or interaction food webs) represent the importance of each species in maintaining the integrity of a community and reflect influence on the growth rate of other species' populations. As shown in Figure 2, limpets Acmaea pelta and A. mitra in the community consume considerable food energy (energy flow web), but removal of these consumers has no detectable influence on the abundance of their resources (functional web). The most effective control was exerted by sea urchin Stronglocentrotus and the chiton Katharina (Ricklefs 2008).
Answer:
D
) ratio of neutrons to protons in each element.
A successful food web needs to have all of the organisms mostly bigger than the ones that they are eating otherwise the food web wouldnt neccessarily work properly and then the food webs would all be messed up.
Finish. The work is done then the work is finish.
<span>11.2 Florida voters. Florida played a key role in the 2000 and 2004 presidential elections. Voter
registration records in August 2010 show that 41% of Florida voters are registered as Democrats
and 36% as Republicans. (Most of the others did not choose a party.) To test a random digit
dialing device that you plan to use to poll voters for the 2010 Senate elections, you use it to call
250 randomly chosen residential telephones in Florida. Of the registered voters contacted, 34%
are registered Democrats. Is each of the boldface numbers a parameter or a statistic?
Answer
41 % of registered voters are Democrats: parameter
36% of registered voters are Republicans: parameter
34% of voters contacted are Democrats: statistic
11.7 Generating a sampling distribution. Let’s illustrate the idea of a sampling distribution in
the case of a very small sample from a very small population. The population is the scores of 10
students on an exam:
The parameter of interest is the mean score ÎĽ in this population. The sample is an SRS of size n =
4 drawn from the population. Because the students are labeled 0 to 9, a single random digit from
Table B chooses one student for the sample.
(a) Find the mean of the 10 scores in the population. This is the population mean ÎĽ.
(b) Use the first digits in row 116 of Table B to draw an SRS of size 4 from this population.
What are the four scores in your sample? What is their mean ? This statistic is an estimate of
ÎĽ.
(c) Repeat this process 9 more times, using the first digits in rows 117 to 125 of Table B. Make a
histogram of the 10 values of . You are constructing the sampling distribution of . Is the
center of your histogram close to ÎĽ?
Answer
(a) ÎĽ = 694/10 = 69.4.
(b) The table below shows the results for line 116. Note that we need to choose 5 digits because
the digit 4 appears twice.
(c) The results for the other lines are in the table; the histogram is shown after the table.</span>
