Lesson 18 Definitions

Question 1

Heterotroph

Answer 1

consumer

Question 2

Autotroph

Answer 2

producer

Question 3

trophic level

Answer 3

organism’s place on food chain

Question 4

detritivore

Answer 4

eats detritus (dead organic material)

Question 5

biological magnification

Answer 5

magnification of certain pollutants as food travels up a food chain

Question 6

natality

Answer 6

birth rate

Question 7

mortality

Answer 7

death rate

Question 8

density

Answer 8

the number of organisms in an area divided by the amount of area

Question 9

biotic potential

Answer 9

maximum rate a population would grow, given optimum food, water, and space

Question 10

environmental resistance

Answer 10

when combined elements restrain a certain species from growing uncontrollably

Question 11

carrying capacity

Answer 11

the maximum population of a particular organism that a given environment can hold

Question 12

succession

Answer 12

different organisms occupy an ecosystem, depending on the stage

Question 13

competition

Answer 13

two species share a requirement for a limited resource

Question 14

predation

Answer 14

one organism eats the other

Question 15

niche

Answer 15

total of all activities and relationships that individuals of a species have

Question 16

altruism

Answer 16

behavior of an animal that benefits another at its own expense

Question 17

kin selection

Answer 17

the evolutionary strategy that favors the reproductive success of an organism’s relatives, even at a cost to the organism’s own survival and reproduction

Question 18

symbiosis

Answer 18

two species interact (includes parasitism, commensalism, and mutualism)

Question 19

species richness

Answer 19

number of different species in an area

Question 20

life history

Answer 20

the series of changes undergone by an organism during its lifetime.