Concept explainers
a.
To draw:
The general shape of age and structure diagrams characteristics of (a) expanding, (b) stable and (c) shrinking population. And also explain why an individual can predict the next several decades of growth by the current age structure of populations.
Introduction:
Age structure graph is also called as population pyramid that shows the distribution of different age groups individuals within a population. Vertical axis of graph shows the different age groups of an individual while horizontal axis shows the gender of an individual. This diagram is used to predict the age distribution and growth of future population.
b.
To determine:
The general shape of age and structure diagram characteristics of a stable population.
c.
To determine:
The general shape of age and structure diagram characteristics of shrinking population.
Want to see the full answer?
Check out a sample textbook solutionChapter 27 Solutions
Pearson eText Biology: Life on Earth with Physiology -- Instant Access (Pearson+)
- 1.) At approximately what year did the human population enter an exponential growth phase? 2.) Prior to that time, what was the approximate carrying capacity of Earth? 3.) State three significant technological developments that have acted to increase the carrying capacity of Earth’s environment since that time. 4.) Provide two examples of density-dependent factors that are contributing to or have the potential to contribute to environmental resistance in human populations.arrow_forwardExplain the difference between logistic and exponential population growth. What do these growth curves look like. Which represents human population growth over the last few thousand years?arrow_forwardSome demographers claim that the total world population has already begun to slow, while others dispute this claim. How would you recognize a true demographic transition as opposed in mere random fluctuations in birth and death rates?arrow_forward
- Write a generalized model for exponential population growth. Define your terms. Then, draw a plot showing an example, being sure to label your axes. Write a formula that extends the preceding model to incorporate carrying capacity, producing sigmoidal population growth. Define your terms. Then, draw a plot showing an example, being sure to label your axes.arrow_forwardA few plant-eating salamanders manage to float on a log to a large island in the Pacific that did not have any other salamander species previously. The salamanders find the island has abundant plants for food and no predators. On average, a salamander has four offspring per year and lives for one year. Refer to the equation for the logistic growth model if you were modeling salamnder population growth with this logistic growth equation, during the first few years, a) N<K b) N=K c) N>K d) there is no relationship between N and Karrow_forwardA population that did not grow in close relation to the amount of resources available in the environment, and dramatically overshot the carrying capacity, would experience: A. logistic growth, such as shown on the S-shaped curve B. exponential growth, such as shown on the J-shaped curve C. unpredictable growth, such as shown on the ?-shaped curve D. exponential growth, such as shown on the S-shaped curve E.logistic growth, such as shown on the J-shaped curvearrow_forward
- In the logistic growth equation the highest instantaneous population growth rate (dN/dt) is reached When the population is smallest, because then intraspecific competion and thereby resource limitation is weakest When the population is near K, because the largest population still growing has the highest growth rate, as it has the highest number of reproducing adults When the population is in the middle between zero and K (N = K/2) because then the trade-off between still having modest negative effects of intraspecific competition on growth rate but having a relatively high population size of individuals that could be reproducing is optimalarrow_forwardIn the logistic model of population growth, per capita growth rates are highest at __ densities and population growth rates are highest at ___ density (NOTE: assume ‘high’ refers to at or near K). A) low, intermediate B) low, low C) low, high D) None of the above are truearrow_forwardThe common carp is an non-native fish species in North America. A few individualsare introduced into a lake near Ottawa, where they experience no predation orcompetition from native fishes. What kind of growth the population of carp isexpected to follow in the first few years following its introduction. 1. linear 2.logistic 3.exponential 4.logarithmicarrow_forward
- In a graph of population size versus time, a J-shaped curve is characteristic of (a) exponential population growth (b) logistic population growth (c) zero population growth (d) replacement-level fertility (e) population growth momentumarrow_forwardIf each adult female powerful owl produces 1 female juvenile (F) each year, the adult survival rate (Sa) is 0.8, the juvenile survival rate (Sj) is 0.4, and the population is N2022=1400 adult females and 1400 juvenile females in 2022, what will be the female population size in 2027 (N2027)? Show your calculations. (hint: use excel to set up a model and check your work)arrow_forwardA population of bats exhibits logistic growth. The carrying capacity is 600 bats and the maximum per capita Growth rate (rmax) is 0.20. The population size was determined periodically. Determine the population growth rates based on a population size of 50, 100, 200, 350, 480, 500, 525, and 600 bats. Include up to three decimal places in your answers. Show all work! üüüüüüüü rmax N (K-N)/K Population growth rate a. 0.20 b. 0.20 c. 0.20 d. 0.20 e. 0.20 f. 0.20 g. 0.20 h. 0.20 b. Describe the relationship between population size and growth rate. üüarrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage Learning