Chapter 52

Question 1

population

Answer 1

A group of organisms of one species that interbreed and live in the same place at the same time

Question 2

quadrats

Answer 2

It marks off an exact area so that the plants in that area can be identified and counted. About quadrats: quadrats should be placed randomly so that a representative sample is taken.

Question 3

evolutionary ecology

Answer 3

lies at the intersection of ecology and evolutionary biology. It approaches the study of ecology in a way that explicitly considers the evolutionary histories of species and the interactions between them.

Question 4

intrinsic rate of increase

Answer 4

The rate at which a population increases in size if there are no density-dependent forces regulating the population

Question 5

mark-recapture study

Answer 5

a method commonly used in ecology to estimate an animal population’s size. A portion of the population is captured, marked, and released. Later, another portion is captured and the number of marked individuals within the sample is counted.

Question 6

immigration

Answer 6

Migration into a place

Question 7

exponential growth

Answer 7

Growth of a system in which the amount being added to the system is proportional to the amount already present: the bigger the system is, the greater the increase.

Question 8

population cycles

Answer 8

a phenomenon where populations rise and fall over a predictable period of time. There are some species where population numbers have reasonably predictable patterns of change although the full reasons for population cycles is one of the major unsolved ecological problems.

Question 9

emigration

Answer 9

migration seen as an the exit of individuals from one region

Question 10

density-independent

Answer 10

Any factor limiting the size of a population whose effect is not dependent on the number of individuals in the population.

Question 11

age structure

Answer 11

This characteristic is as simple as it sounds: it’s a summary of the number of individuals of each age in the population. Age structure is useful in understanding and predicting population growth.

Question 12

demography

Answer 12

the science of populations.

Question 13

population density

Answer 13

a measure of the number of organisms that make up a population in a defined area.

Question 14

age pyramid

Answer 14

a graphical illustration that shows the distribution of various age groups in a population (typically that of a country or region of the world), which forms the shape of a pyramid when the population is growing.

Question 15

generation

Answer 15

All of the offspring that are at the same stage of descent from a common ancestor: Mother and daughters represent two generations.

Question 16

density-dependent

Answer 16

Any factor limiting the size of a population whose effect is dependent on the number of individuals in the population.

Question 17

replacement rate

Answer 17

The rate at which new offspring are born compared to the death rate.

Question 18

life table

Answer 18

a table which shows, for each age, what the probability is that a person of that age will die before his or her next birthday (“probability of death”).

Question 19

carrying capacity

Answer 19

the maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water, and other necessities available in the environment.

Question 20

zero population growth

Answer 20

A condition in which a population neither grows nor declines, because the number of births in a year equals the number of deaths.

Question 21

per capita rate of increase

Answer 21

A rate of increase which is proportional to the number of individuals in a population.

Question 22

cohort

Answer 22

a group of individuals that are the same age and can be followed through time

Question 23

logistic growth equation

Answer 23

expressed as change in population/change in time=growth rate(initial population)(carrying capacity -initial population/carrying capacity)

Question 24

logistic population growth

Answer 24

the density-dependent decrease in growth rate as a population size approaches carrying capacity

Question 25

fecundity

Answer 25

the average number of female offspring produced by a single female in the course of her lifetime

Question 26

finite rate of increase

Answer 26

the rate of increase of a population over a given period of time. calculated as the end population size over the start population size

Question 27

age-specific fecundity

Answer 27

the average number of female offspring produced by a female in a certain age class

Question 28

population viability analysis

Answer 28

a model that estimates the likelihood that a population will avoid extinction for a given time period

Question 29

density dependent factor

Answer 29

in population ecology referring to any characteristic that varies depending on population density

Question 30

age class

Answer 30

all the individuals of a certain age in a population

Question 31

fitness trade-off

Answer 31

in evolutionary biology, an inescapable compromise between two traits that cannot be optimized simultaneously

Question 32

life history

Answer 32

the sequence off events in an individuals life from birth to reproduction to death, including how an individual allocates resources to growth, reproduction, and activities or structures related to survival

Question 33

population dynamics

Answer 33

changes in the size and other characteristics of populations through time

Question 34

net reproductive rate

Answer 34

the growth rate of a population per generation; equivalent to the average number of female offspring that each female produces over her lifetime

Question 35

metapopulation

Answer 35

a population made up of many small, physically isolated populations