Chapter 9

Question 1

population dynamics

Answer 1

major abiotic and biotic factors that tend to increase or decrease the population size and age and sex composition of a species.

Question 2

density

Answer 2

number of individuals in a certain space.

Question 3

age distribution

Answer 3

the proportion of individuals of each age in a population

Question 4

clumping

Answer 4

when a species stay in tight packs.

Question 5

uniform dispersion

Answer 5

all the species have an equal space between them.

Question 6

random dispersion

Answer 6

when a species is distributed unevenly in an area.

Question 7

immigration

Answer 7

migration of a species into a country or area to take up permeant residence

Question 8

emigration

Answer 8

when a species leaves their native country and goes to live somewhere else.

Question 9

prereproductive stage

Answer 9

organisms that are not mature enough to reproduce.

Question 10

reproductive stage

Answer 10

organisms that are capable of reproduction

Question 11

post reproductive stage

Answer 11

and organisms that are too old to reproduce.

Question 12

biotic potential

Answer 12

maximum rate at which the population of a given species can increase when there are no limits on its rate.

Question 13

intrinsic rate of increase

Answer 13

rate at which a population could grow if it had unlimited resources.

Question 14

environmental resistance

Answer 14

all the limiting factors that act together to limit the growth of a population.

Question 15

carrying capacity

Answer 15

maximum population of a particular species that a given habitat can support over a given period.

Question 16

logistic growth

Answer 16

pattern in which exponential population growth occurs when the population is small, and the population growth decreases steadily with time as the population approaches the carrying capacity.

Question 17

exponential growth

Answer 17

growth in which some quantity, such as population size or economic output, increases at a constant rate per unit of time (such as 2% per year). Ex: 2, 4, 8, 16, 32, 64 and so on; when the increase in quantity over time is plotted, this type of growth yields a curve shaped like a J.

Question 18

sigmoid/S-shaped curve

Answer 18

leveling off of an exponential, J-shaped curve when a rapidly growing population exceeds the carrying capacity of its environment and ceases to grow.

Question 19

overshoot

Answer 19

organisms use up their resource supplies and temporarily exceed the carrying capacity of the environment.

Question 20

reproductive time lag

Answer 20

the period need for the birth rate to fall and the death rate to rise in response to resource overconsumption.

Question 21

dieback/crash

Answer 21

sharp reduction in the population of a species when its numbers exceed the carrying capacity of its habitat.

Question 22

density-independent population control

Answer 22

affects a population’s size regardless of its density. ex: flood

Question 23

density-dependent population control

Answer 23

factors that limit population growth have a greater effect as a population’s density increase. ex: no food

Question 24

stable fluctuation

Answer 24

a species whose population size is said to have a fairly stable population size.

Question 25

irruptive fluctuation

Answer 25

their population growth may occasionally explode, to a high peak and then crash to a more stable lower level or in some cases a very level.

Question 26

cyclic fluctuation

Answer 26

population size over a regular time period, populations rise and fall.

Question 27

irregular fluctuation

Answer 27

some populations appear to have irregular behavior in their changes in population sir, with no recurring pattern.

Question 28

asexual reproduction

Answer 28

reproduction in which a mother cell divides to produce two identical daughter cells that are clones of the mother cell. this type of reproduction is common in single-celled organisms.

Question 29

r-selected species

Answer 29

species with a capacity for a high rate of population increase (r). have many, usually small offspring and give them little or no parental care or protection.

Question 30

K-selected species

Answer 30

species that produce a few, often fairly large offspring but invest a great deal of time and energy to ensure that most of those offspring reach reproductive age.

Question 31

survivorship curve

Answer 31

graph showing the number of survivors in different age groups for a particular species.

Question 32

late loss

Answer 32

a population that typically has high survivorship to a certain age , then high mortality.

Question 33

early loss

Answer 33

a population survivorship is low early in life.

Question 34

constant loss

Answer 34

a population shows fairly constant death rate at all ages.

Question 35

founder effect

Answer 35

when a few individuals in a population colonize a new habitat that is geographically isolated from other members of the population.

Question 36

demographic bottleneck

Answer 36

occurs when only a few individuals in a population survive a catastrophe such as a fire of hurricane.

Question 37

genetic drift

Answer 37

involves random changes in the gene frequencies in a population that can lead to unequal reproductive success.

Question 38

inbreeding

Answer 38

occurs when individuals in a small population mate with one one another.

Question 39

metapopulations

Answer 39

mobile populations that are geographically separated from one another can exchange genes when some of their members get together occasionally and mate.

Question 40

sexual reproduction

Answer 40

reproduction in organisms that produce offspring by combining sex cells or gametes (eggs or sperm) from both parents. this produces offspring that have combinations of traits from their parents.