Q: A researcher uses the mark-recapture method to estimate the population size of turtles in a pond. She marks 40 turtles, releases them, and later captures 50 turtles, 10 of which are marked. What is the estimated population size ($$N$$)?

$$N = \frac{40 \times 50}{10} = 200$$

Question 1

Which of the following best describes the difference between an exotic species and an invasive species?

Accepted Answer

An exotic species is introduced to a new area but does not necessarily cause harm, whereas an invasive species is an introduced species that causes ecological or economic damage.

Question 2

A scientist is studying the effect of sunlight angle on climate. Which of the following best explains why the equator is warmer than the poles?

Accepted Answer

The equator receives sunlight at a higher angle of incidence, resulting in more concentrated solar energy per unit area.

Question 3

Which of the following is the best definition of a biome?

Accepted Answer

A large geographic area defined by its climate, vegetation, and characteristic organisms.

Question 4

A population of deer in a forest is observed to have a clumped distribution. Which of the following is the most likely explanation for this pattern?

Accepted Answer

Resources such as food and water are unevenly distributed, causing deer to gather in certain areas.

Question 5

Which equation correctly represents exponential population growth?

Accepted Answer

$$\frac{dN}{dt} = rN$$

Question 6

If a population surpasses its carrying capacity ($$K$$), what is the most likely outcome?

Accepted Answer

The population will crash due to resource depletion and may oscillate around $$K.$$

Question 7

Which of the following best describes the difference between fundamental and realized niche?

Accepted Answer

The realized niche is the portion of the fundamental niche actually occupied due to biotic interactions such as competition.

Question 8

Which of the following is an example of a top-down control in an ecosystem?

Accepted Answer

Predators regulating the population size of herbivores.

Question 9

A researcher uses the mark-recapture method to estimate the population size of turtles in a pond. She marks 40 turtles, releases them, and later captures 50 turtles, 10 of which are marked. What is the estimated population size ($$N$$)?

Accepted Answer

$$N = \frac{40 	imes 50}{10} = 200$$

Question 10

Which of the following is an example of secondary succession?

Accepted Answer

Regrowth of a forest after a wildfire that left the soil intact.

Question 11

Which of the following best describes the concept of a keystone species?

Accepted Answer

A species whose impact on its community is disproportionately large relative to its abundance.

Question 12

Which of the following is an example of Batesian mimicry?

Accepted Answer

A non-toxic butterfly species resembling a toxic butterfly species.

Question 13

Which of the following best explains why seasons occur on Earth?

Accepted Answer

The tilt of Earth's axis causes different angles of sunlight at different times of the year.

Question 14

Which of the following is a density-independent factor affecting population size?

Accepted Answer

A severe drought reducing water availability.

Question 15

Which of the following best describes the Shannon diversity index?

Accepted Answer

A measure that combines species richness and evenness to quantify community diversity.

Question 16

Which of the following is an example of a constitutive defense in plants?

Accepted Answer

Thorns present at all times on a rose bush.

Question 17

Which of the following scenarios best illustrates the concept of character displacement?

Accepted Answer

Two bird species evolve different beak sizes when living together, reducing competition for seeds.

Question 18

Which of the following is a real-world example of mutualism?

Accepted Answer

Bees pollinating flowers while collecting nectar.

Question 19

Which of the following best describes the Coriolis effect?

Accepted Answer

The deflection of moving air and water due to Earth's rotation, causing global wind patterns.

Question 20

Which of the following is the best example of an inducible defense?

Accepted Answer

A plant increasing toxin production only after being grazed by insects.

Ecology: Introduction, Population, and Community Study Guide

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