Learning Materials
Features
Discover
Chapter 36: Problem 20
Species that have many offspring at one time are usually _______. a. r-selected b. K-selected c. both r- and K-selected d. not selected
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
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.
\(\begin{array}{|c|c|}\hline \text { Date } & {N} \\ \hline 5 / 1 /12 & {56} \\\ \hline 6 / 1/12 & {98} \\ \hline 7 / 2 / 12 & {203} \\ \hline 8 / 10 / 12 & {421} \\ \hline\end{array}\) These data were collected on a population of beetles in Florida. Based on the data, how would you describe population growth in this case and what do you predict about growth of this population in the future? Explain your reasoning. a. Population shows logistic growth, as number of individuals doubles every month and will likely continue to grow logistically until its resources become depleted. At that point, the population growth rate will slow down and level off to zero. b. The population shows exponential growth, as the number of individuals doubles every month and will likely grow logistically in the future when the resources become limited. At that point, the population growth rate will slow down and level off to zero. c. The population shows exponential growth, as number of individuals doubles every month and will likely continue to grow exponentially until its resources become limited. At that point, the growth will become logistic; the population growth rate will slow down and level off to zero. d. The population shows logistic growth and is likely to grow exponentially as the resources are probably increasing. The population growth rate will increase in the future as well.
Different species have different survival curves. A Type III survival curve would most likely be observed for _____. a. whales b. seals c. salmon d. polar bears
Some fish swim in schools, which can respond rapidly by moving quickly away from predator threats. In schools, fish swim in a coordinated pattern without moving chaotically and bumping into one another. Which type of communication between individuals could account for the precisely coordinated movements of all of the fish in a school in response to a threat? a. aural signals b. pheromone signals c. tactile signals d. visual signals
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