Learning Materials
Features
Discover
Chapter 36: Problem 13
Species with limited resources usually exhibit a(n) ____ growth curve. a. logistic b. logical c. experimental d. exponential
Over 30 million students worldwide already upgrade their learning with 91影视!
These are the key concepts you need to understand to accurately answer the question.
All the tools & learning materials you need for study success - in one app.
Get started for free
The following statements compare r-selected and Kselected species. Identify the statement that makes an accurate comparison. a. r-selected and K-selected species both have limitations in the amount of energy they can invest in reproduction, so they both use similar strategies. b. r-selected and K-selected species both have limitations in the amount of energy they can invest in reproduction, but they use completely different strategies. c. r-selected and K-selected species use similar reproductive strategies but r-selected species require less energy to reproduce than K-selected species. d. r-selected and K-selected species use different reproductive strategies because r-selected species require less energy to reproduce than Kselected species.
The following problem extends the Hardy-Weinberg model of population dynamics that was covered in Chapter 19. It applies mathematics that would be appropriate after a second course in Algebra. While the concept applied in this problem are within the scope of the Exam the mathematical representations are not and the item is provided to allow students who are able another look at the concepts. The Hardy-Weinberg model of population dynamics is an algebraic representation of the relationships among genotype frequencies, F, and the probability of the dominant allele A, p, and the recessive allele a, q. The Hardy-Weinberg model of population dynamics is based on several assumptions. One of these assumptions is 鈥渞andom mating.鈥� If all genes in a population are equally able to reproduce, this means that all genes are equally fit and equally fertile. Consequently, the population never evolves. Populations do evolve and the Hardy-Weinberg model can be modified slightly to allow evolution to occur. Suppose that there is an initial population at generation zero and the probability of the dominant allele at that time is p0. Later, at population k the probability is different. But if the frequencies of the three different combinations of alleles is known then the probabilities pk and qk can be calculated at generation k (1) \(p_{k}=F_{k}(A A)+1 / 2 F_{k}(A a) q_{k}=F_{k}(a a)+1 / 2 F_{k}(A a)\) And since p and q are probabilities for a case where only two alleles exist, p+q=1. Then also (p+q)2=1, leading the Hardy-Weinberg equation (2) \(F_{k}(A A)=p_{k}^{2} w_{A A} / W F_{k}(A a)=2 p_{k} q_{k} w_{A a} / W F_{k}=\) \(q^{2}_{k} w_{a a} / W W=p^{2} w_{A A}+2 p q w_{A a} / q^{2} w_{a a}\) Haldane divides by the factor \(\mathrm{W}=\mathrm{F}_{\mathrm{k}}(\mathrm{A} \mathrm{A})+\mathrm{F}_{\mathrm{k}}(\mathrm{Aa})+\mathrm{F}_{\mathrm{k}}(\mathrm{aa})\) so that the probabilities that are still calculated with equation (1) to continue to satisfy the condition for p and q to represent probabilities:\((p+q)^{2}=1\) A. Justify Haldane's model in terms of what the factors \(\mathrm{w}_{\mathrm{AA}}, \mathrm{w}_{\mathrm{Aa}}\) and \(\mathrm{w}_{\mathrm{aa}}\) mean. B. Suppose that \(w_{A A}=w_{A a}=1,\) but that \(w_{\text { aa }}=0.8\) . Predict what will happen to the population over time. Fitness is determined by the environment. Moree (The American Naturalist, 86, 1952) measured the relative fitness in Drosophila melanogaster of a recessive allele that imparts black eye color as population density increases. A varying number of flies with an equal number of males and females were placed in a pint jar and progeny counted. In each experiment the population was initially heterozygous. C. Apply Haldane鈥檚 approach to calculate the probabilityp in the first generation after mating 150 female and 150 male flies that are heterozygous using wAA = wAa = 1. Rendel (Evolution, 5, 1951) conducted an investigation of the dependence of fecundity (fertility) on light in ebonyeyed D. melanogaster. A summary of some of the data that he reported is shown in the table below: D. Pose two scientific questions concerning the behavioral response indicated by the data that can be tested experimentally. E. Is there a question you can add here to wrap up this set with this LO from the list? In this case 鈥渓ight鈥� is the single environmental factor, and they two phenotypes are ebony and wild type that result from different genotypes within the population of flies.
Describe phototaxis. a. Phototaxis is the directed movement of an organism in response to gravity. b. Phototaxis is the long-range movement of an organism in response to a change in season. c. Phototaxis is the movement of an organism in search of food. d. Phototaxis is the directed movement of an organism in response to light
Fruit flies are found in many different areas in the world. Fruit flies that are resistant to cold temperatures tend to have decreased fecundity at early ages compared to flies that are not capable of surviving the cold. Explain a likely reason for why this set of traits is observed. (credit: Anthony Zera Publications) a. Flies having traits that traded early reproductive energy for greater storage of energy in their bodies were favored via natural selection because they survived the cold better than flies that did not have these traits. b. In cold conditions, flies have less need for reproduction than in warm conditions and so energy normally used for reproduction is diverted to other survival functions. c. Flies respond to weather conditions to shift their energy resources to either storage in their bodies in the cold or to reproduction when conditions become warm again. d. All fruit flies have the same genetic makeup, but express different patterns of genes under different conditions, which results in expression of certain genes for cold conditions and others for warm conditions.
A pond ecosystem in an open field begins to be shaded by the growth of trees around its perimeter. Predict changes in this pond after the trees grow large enough to completely shade the pond. a. The population sizes of all organisms will decrease in response to lower energy flowing into the pond. b. The population densities of all organisms will increase in response to lower temperatures in the pond. c. The population distributions of large organisms will shift from clumped to random in response to lower energy flowing into the pond. d. The population distributions of small organisms will shift from uniform to clumped in response to lower temperatures in the pond.
What do you think about this solution?
We value your feedback to improve our textbook solutions.
Explanations 
Textbooks 
Flashcards 
91影视 AI 
Notes 
Study Plans 
Study Sets 
Find a degree 
Magazine