holland ecology exam 2

when conditions are favorable for a population at low density, such as when a species colonizes a new environment, population growth is typically

exponential

the pattern shown in figure 9.6 best resembles

exponential growth

Which model of population growth would you employ if reproduction occurs in discrete time periods rather than being continuous?

geometric

a systematic compilation of mortality and and survival data for a population is called a

life table

if survival rates do not vary with age as in many species of perennial plants, reptiles, adult birds, and rodents, survivorship curves are typically

type 2

the Dall sheep (a) curve represents which type of survivorship curve?

type 1

the number of births per female of age x is referred to as the:

age-specific birthrate

the average number of female offspring born to a female over her lifetime is referred to as the

gross reproductive rate

why is the b0 = 0 at time period x0 for some species?

some species do not reproduce during the final time period

a population that is growing has a net reproductive rate (R0) that is

>1

a population reaches a stable-age distribution when the

proportion of individuals in each age group remains the same

the leading cause of current species extinction is

habitat destruction

which populations are at greatest risk for extinction?

very small ones

a trade-off for having many offspring would be

that they would likely be small in size

an advantage to sexual reproduction is

increased genetic variability

human reproductive systems are best described as

dioecious

at birth, California sheephead fish begin their life as females and then become males. this is referred to as

sequential hermaphroditism

the data in the figure above support which of the following trade-offs

the number of offspring is correlated with growth

in long-lived species, the primary advantage of delaying reproduction (late maturity) is

larger body size during the first reproduction event

animals with extremely high fecundity tend to have

lower survival rates

altricial young are relatively

helpless at birth but require relatively little time for incubation and gestation

an insect larva that is immediately ready to move away fromits hatching site and feed after birth is termed

precocial

pacific salmon migrate upstream and after breeding, soon die. they are termed

semelparous

true or false? weedy plants are considered to be k-strategists

false

the carrying capacity refers to the

maximum sustainable population size for the prevailing environment

in logistic growth, the point at which population growth ceases is referred to as the

carrying capacity

the figure above depicts which type of population growth

logistic

which of the following is density-independent factor?

extreme weather event

as the density of a population increases the

individual growth rate decreases

you see two squirrels fighting over a food resource. this most likely represents

contest competition

what might be an outcome of planting soybean plants at very high densities in a field?

reduced seed production per plant

As population density increases in harp seals (Phoca groenlandica), females

begin reproduction at a larger age

which statement about stress is incorrect?

- stress increases as population density increases

- stress can trigger the release of specific chemical signals or pheromones

- stress can stimulate growth and increase the rate of reproduction

- stress results in increased vulnerability to disease

stress can stimulate growth and increase the rate of reproduction

the induvial that disperse in response to high population density are

usually, the younger members of the population

among mammals the home range is usually larger for

carnivorous species than for herbivorous species of the same body size

this figure illustrates that territory size is positively correlated with

body size

when individuals in a small population have difficulty finding a mate, this is referred to as

the allee effect

when the trunk or limb of a tree provides the substrate on which an epiphytic orchid grows, the arrangement benefits the orchid, which gets nutrients from the air and moisture from aerial roots while the tree is unaffected. the relationship is referred to as

commensalism

when the relationship between two interacting species is detrimental to the populations of both species the interaction is referred to as

competition

which of the following interactions would be considered predation?

+-

a remora feeds on the scraps that escape from a shark's mouth while feeding. it has no clear positive or negative impact on the shark. this is an example of

commensalism

what is the difference between a parasite and a parasitoid?

a parasitoid typically kills its host

which of the following has the strongest impacts on species 1 population size? N2 =

750

the length of a butterfly tongue perfectly matches the nectar tube of a flower it pollinates. this is an example of

coevolution

what might happen over time if two bird species competed for the same seed resource and one preferred larger seed while the other species preferred smaller ones

break sizes might shift over time

On a dare, a student challenges another student to lick a California newt (Taricha torosa). From which population of newts should the student grab an individual to reduce his or her risk of a toxic dose?

from a population with no garter snakes

the neurotoxin that taricha spp. possess to ward off predators is

tetridotoxin

mycorrhizal fungi have a mutually beneficial relationship with plants in environments with soils that are

low in nutrients

the red line in the figure above (the furthest to the right) represents

highly resistant garter snake population

A species of cattail inhabits both deep and shallow water in the absence of a competitor but only shallow water in the presence of it. This is an example of

a realized niche

the process where one species gives rise to several others that exploit different features of the environment and occupy different niches is known as

adaptive radiation

what does the following formula represent? dN1/dt = r1N1(1-(N1+N2)/K1)

population growth of species 1 in presence of species 2 limited by a shared carrying capacity

chemicals released by plants to inhibit germination and establishment of other species is known as

allelopathy

in the following formula, what does B (beta) represent in dN2/dt = r2N2(1-(N2+BN1)/K2)

competition coefficient

according to the figure above, when these 2 species are grown together, what will the outcome be?

P. aurelia wins

competitive exclusion principle assumes that the

environmental conditions remain constant

How can one grass species be dominant one year, while another is dominant a few years later and then the first becomes dominant again?

changes in precipitation across years

Typically species compete for

multiple resources simultaneously.

The different chipmunk species correspond to the different tree species along an elevational gradient. This is likely because

several resource factors for both groups change with elevation

The K in the term K-strategist refers to

carrying capacity

The net outcome of predator-prey interactions in the basic Lotka-Volterra models is that

predator and prey populations oscillate with each predictably increasing and decreasing in response to the other

in a simple experiment involving only predator and prey with no refuge,

predators will typically drive their prey to extinction

Huffaker's experiment involving 2 species of mites and oranges show that

with sufficient complexity, predator and prey populations will oscilate

in the lotka-volterra model of predator- prey interactions, population growth is regulated through

reproduction for the predator and mortality for the prey

when predators come together in areas of high prey density, it is referred to as

an aggregative response

the figure above shows that

lynx populations numerically respond to hare populations

Coevolution between predator and prey suggests

as predators become smarter at catching prey, prey will become smarter at escaping predation.

If you are stranded on a desert island, which prey should you avoid consuming?

brightly colored brey

which of the following is an example of cryptic coloration?

a motled brown bird that nests on the ground

which of the following has caused massive declines in US commercial fish populations?

huge factory trawlers and high tech detection methods such as use of planes and drones