General Ecology Exam 2

Which of the following terms describes the idea that because all individuals have limited access to energy, any energy acquired must be distributed to one of life’s necessary physiological functions, which reduces the amount that can be used for other physiological functions?

Principle of allocation

In the mathematical model for the principle of allocation, what does the E_assimilation represent?

The total energy converted to an organism’s biomass

Which of the following phrases describes how an individual animal would act to maximize energy intake relative to the energy spent acquiring that energy, with the overall goal of maximizing its evolutionary fitness?

Optimal foraging theory

When considering optimal foraging theory and using the individual energy allocation model, what relationship between E_intake and E_respiration would result in a predator making an optimal choice when it comes to consuming a prey item?

E_intake > E_respiration

When using the foraging model, which of the following variable combinations would mean that a predator has expended as much energy as they have gained from a prey item?

1. P = 1

2. P < 1

3. P > 1

4. E = C

5. E > C

6. E < C

1 and 4

Search costs for predators are minimal when _____, and handling costs for predators are high when ____.

prey is abundant; prey is hard to capture

True or False? The E_waste term in the principle of allocation equation for energy has greater importance to an organism than the W_waste term in the principle of allocation for water.

false

Which biome would see a plant devoting a large amount of energy to growing its roots to increase its intake of water from the soil?

Desert

Which photosynthetic pathway is the most energy-efficient method, and has the Calvin-Benson cycle occurring in the mesophyll cells?

C3 photosynthesis

Which of the following photosynthetic pathways would be best suited for a temperate forest?

C3 photosynthesis

Which of the following photosynthetic pathways is the best at conserving water?

CAM photosynthesis

Many plants, marine invertabrates, and marine fishes are ____, meaning that they do not regulate their internal temperature.

poikilotherms

Tuna are fish that regulate their internal temperature. They are considered _____, because they can generate lots of metabolic heat while swimming, but they do not keep their internal temperature within a narrow range.

non-homeotherm

Which of the following terms would describe a specific set of abiotic and biotic conditions under which an organism can live and reproduce?

Niche

The figure shows the Devil’s Hole pupfish’s water temperature and dissolved oxygen requirements. Which niche space term describes the reduced area (dotted line oval) present within the rectangle?

Realized niche space

What does the M in the mark-recapture model stand for?

Number of individuals marked and released during the first survey

Which statement defines a population?

A group of individuals of same species that is spatially distinct from other groups of individuals of the same species that can mate.

What does λ represent in the discrete-time population growth model?

The finite per capita rate of population growth

Which of the lines in the figure below represents a λ = 1 using the discrete-time population?

Line C

Which of these described populations would violate one of the geometric population growth model’s assumptions?

Wood rats that breed year-round

Which of the following statements describes an assumption made by the geometric population growth model?

Birth and survival rates will be constant for all individuals regardless of sex, age, or other differences.

What is one difference between the continuous-time population growth model and the discrete-time population growth model?

The discrete-time population growth model is best used for organisms that breed at specific intervals or during a discrete time period, whereas the continuous-time population growth model is best used for organisms that breed at any time and not during a discrete time period.

How did density dependence manifest in the experimental North American elk populations studied by John Kie and his colleagues?

Female elk and lower fat stores in the high-density plots.

In the logistic growth model, what should we expect of the parameters if the population size is small?

N < K

The parameter, r_dis is used for the _____, whereas the parameter, r_max is used for the ____.

discrete-time logistic growth model; continuous-time logistic growth model

How is carrying capacity different in the two types of logistic population growth?

The continuous-time logistic growth model’s population will approach the carrying capacity but never shoot above it, whereas the discrete-time logistic growth model’s population can oscillate around carrying capacity.

Which of the following r_dis values would result in stable limit cycles for a population that is under the discrete-time density-dependent population growth model?

2.25

The discrete-time logistic growth model can have four different dynamics that can mimic a species population growth around carrying capacity. Which of the four dynamics looks similar to how the population using the continuous-time logistic growth model would grow around carrying capacity?

Monotonic damping

What characteristics would be shared between species that have a Type I survivorship curve?

They have a high juvenile survival rate.

The geometric and exponential growth models make a similar assumption that birth and death rates will remain constant through time and regardless of population abundance. This assumption cannot be realistic as birth and death rates will vary based on a population’s abundance. Which term describes this phenomenon?

Density dependence

The equation for the ____ is Nt = N0ert, whereas the equation for the _____ is Nt = N λt.

continuous-time population growth model; discrete-time population growth model

Which two mechanisms will be excluded from a population growth model when a population is closed?

Immigration and emigration

Intraspecific competition differs from interspecific competition in that:

Intraspecific competition involves interactions between individuals of one species, whereas interspecific competition involves interactions between individuals of different species.

Which is true when comparing a species’ fundamental niche with its realized niche?

The fundamental niche will be equal to or greater than the realized niche.

The following figure illustrates the soil nitrogen utilization curves of two population of plants.

At what concentration (in ppm) would you expect the least amount of competition between Species 1 and Species 2 for soil nitrogen?

70

The following figure depicts the Tilman zero net growth isoclines (ZNGIs) for populations of two plant species, Population A and Population B, for two resources, soil nitrogen, and soil phosphorus concentrations. Based on these isoclines, what are the critical soil nitrogen and phosphorus concentrations for Population B?

15 ppm N and 5 ppm P

Refer the figure from Question 36 - it depicts the Tilman zero net growth isoclines (ZNGIs) for populations of two plant species, Population A and Population B, for two resources, soil nitrogen and soil phosphorus concentrations.

What is the predicted outcome if the supply point concentration of soil nitrogen is 10 ppm, and the supply point concentration of soil phosphorus is 50 ppm? In 2-3 sentences explain your answer.

Both will die.

Two species of Galapagos finch, Geospiza fortis and Geospiza fuliginosa, exhibit similar variation in their beak depth when found allopatric on the islands of Los Hermanos and Daphne Major, respectively. However, each species exhibits a shift in variation in beak size when found sympatric on the island of Santa Cruz, as shown in the figure below.

The evolutionary shift in the variation of beak depth because of competition between these species can be best described as _______.

character displacement

The lines in the following figure represent the zero growth rate isoclines for populations of two species, Population 1 (N1, solid line) and Population 2 (N2, dotted line).

What is the expected competitive outcome based on the positions of the two isoclines?

Population 1 will competitively exclude Population 2.

The line in the following figure represents the zero-growth rate isocline for a population (N1) in response to changes in the abundance of individuals of a competing population (N2).

What would K1 be for Population 1?

90

Following the Tilman model of competition, the equilibrium point of resource availability (where the flow of resources out of the system equals the flow of resources entering the system, without considering their removal by a population) is referred to as the:

resource supply point

This is NOT a question. Please refer to this figure to answer question 43.

The figure in Q42 presents the zero-growth rate isocline for a population, Population 1, and three points representing different scenarios where the abundances of Species 1’s Population (N1) and Species 2’s Population (N2) differ.

Based on the figure, at which point (A,B, or C) would Population 1 experience the fastest rate of population growth? In 2-3 sentences explain your answer.

zero-growth rate isocline = all same

Competitive exclusion

In class, we watched the “Salamander of the Gods” video. You saw stories about 2 salamanders:

a. What unique characteristics do axolotl and achoque share?

b. While working on the conservation of achoque, Omar and his team came to the Basílica de Nuestra Señora de la Salud about 20 years ago… Not for divine intervention. Why? What can nuns help with?

“Does Nature Have Rights?” Give 2 examples of how EcoMinga protects local biodiversity without invoking the constitution’s right of nature.