Chapter 8 - Population Ecology Flashcards
A group of individuals of the same species inhabiting a given area is called a(n) ________.
population
An individual tree or plant produced by sexual reproduction and thus arising from a zygote is a genetic individual’ known as a(n) ________.
genet
The ________ of a population describes its spatial location’ the area over which it occurs
distribution
As a result of environmental heterogeneity’ most populations are divided into smaller populations’ referred to as local ________
subpopulation
________ defines the size of a population, the number of individuals in it
Abundance
Population ________ is the number of individuals per unit area, or per unit volume.
Density
Because a direct count of all individuals within a population is often impossible, population density is usually estimated by one or more methods of ________
sampling
Counting the total number of individuals within a square or rectangle of known area, referred to as a(n)________’ is a sampling method that is commonly used to study plants or other sessile animals
quadrat
Populations can be divided into three ecologically important age classes: pre-reproductive, reproductive, and ________.
postreproductive
A graph that compares the relative number of individuals within different age groups of a population is called an age ________.
pyramid
In most mammalian populations, the ________ sex ratio at birth is often weighted toward males
secondary
Individuals moving from another location into a subpopulation is referred to as ________.
immigration
A round-trip movement of an individual from one place to another and back again is called ________.
migration
The primary factors driving the dynamics of population abundance are the demographic processes of ________ and ________.
birth; death
Which of the following is not a feature of a population;? A) size B) density C) number of species D) distribution
C) number of species
Which of the following is not a feature of a population? A. size B. density C. number of species D. distribution
C. number of species
A module that is produced asexually by an original genetic individual' which may remain physically linked to the parent or ma$ be separate' is referred to as a A. genet B. ramet C. clone D. bud
B. ramet
Which of the following represents a modular organism? A. lizard B. Coral C. Dog D. ant
B. Coral
A group of local subpopulations is called a(an) A. community B. species C. metapopulation D. ecogroup
C. metapopulation
The area inhabited by all individuals of a particular species is known as this population's A. geographic range B. density C. ecosystem D. habitat
A. geographic range
A population’s density is calculated as the
A. area over which the population is distributed.
B. number of individuals within the population.
C. unit of area divided by the number of individuals.
D. number of individuals per unit area.
D. number of individuals per unit area.
In populations of animals that defend an area for their own exclusive use or in plants thatcompete intensively for belowground resources such as water or nutrients' the spatial distributionof individuals is usually A. homogenous. B. clumped. C. random. D. uniform.
D. uniform
An ecologist counts the number of individuals in five samples of equal area for four species of organisms. Which of these counts best represents a clumped population? A. 23, 21, 25, 22, 18 B. 133, 124, 113, 128, 119 C. 47, 18, 93, 12, 28 D. 12, 13, 12, 13, 11
C. 47, 18, 93, 12, 28
Which of the following sampling techniques represents an index of abundance rather than anestimate of density;
A. number of oak trees within a quadrat
B. number of bear droppings along a trail
C. ratio of marked and unmarked mice in a field
D. number of ducks on a pond
B. number of bear droppings along a trail
The age of a tree is best approximated by
A) estimating tree height.
B) counting tree growth rings.
C) measuring the diameter of a trunk at breast height (dbh).
D) counting the number of leaves.
counting tree growth rings
The demographic age pyramid of a rapidly growing population is
A) wide at the base’ narrow at the top.
B) wide at the top’ narrow at the bottom.
C) wide at top and bottom’ narrow in the middle.
D) similarly wide from top to bottom
A. wide at the base’ narrow at the top.
The movement of individuals in space is called A) distribution. B) migration. C) dispersal. D) density
C. dispersal
An ecologist spent a year studying the population dynamics of a species of duck on a lake. At the beginning of the year' there were 86, adults. Of these' 16 adults left the lake' 12 adults arrived on the lake from elsewhere' 76, chicks hatched from eggs' 24 chicks survived to become adults'and 8 adults died. How many individuals emigrated? A. 8 B. 12 C. 16 D. 24
C. 16
Which of the following organisms is listed as a Federal Noxious Weed because of its profound negative impacts on ecosystems of the southeastern United States; A. gypsy moth B. corn C. ivy D. kudzu
D. kudzu
The members of a population often belong to different species.
False
A genet is produced asexually.
False
A ramet is genetically identical to its original parent
True
An individual plant is often more difficult to recognize than an individual animal
True
The distribution of species is rarely determined by minimum and maximum temperature tolerances.
False
Most populations are divided into subpopulations.
True
A uniform distribution of individuals within a population occurs if each individual’s position isindependent of others’ positions.
False
The most common spatial distribution among individuals within a population is clumped.
True
Ecological density is a measure of the number of individuals per unit of available living space
True
The density of a population is usually measured by counting every individual.
false
A quadrat is usually used to measure density in mobile populations of animals
false
The age of a fish can be determined by counting the annual rings of otoliths (ear stones)
True
Small trees are often the same age as large individuals in the canopy.
True
The sex ratio in a population is usually fixed and does not vary among age classes
False
All animals disperse actively’ whereas all plants disperse passively.
False
Unlike the one-way movement of an individual in emigration and immigration’ migrationrefers to round-trip movements
True
