Part 3 Topic D

Question 1

external fertilization

Answer 1

fertilization that takes place outside the body of the female; in aquatic organisms, for example, eggs and sperm are released into the water

Question 2

internal fertilization

Answer 2

fertilization that takes place inside the body of the female

Question 3

internal fertilization is an adaption for…

Answer 3

living on land, prevents gametes from drying out (some marine animals reproduce this way too)

Question 4

external fertilization is generally associated with the release of….

Answer 4

large numbers of gametes and the production of large numbers of offspring (each has a lower probability of survival)

Question 5

internal fertilization typically produce….

Answer 5

fewer offspring and invest considerable time and energy into raising offspring

Question 6

r-strategist

Answer 6

a species that produces large numbers of offspring but provides few resources for their support

Question 7

K-strategist

Answer 7

a species that produces relatively few young but invests considerable resources into their support

Question 8

according to the model of r-stragetists and K-strategists, the environment places ______

Answer 8

selective pressures on organisms to drive them in one or the other direction

Question 9

what environment did r-strategists evolve in?

Answer 9

unstable, changing, and unpredictable environments; advantage of reproducing quickly and producing many offspring

Question 10

what environment did K-strategists evolve in?

Answer 10

stable, unchanging, and predictable environments; more crowding and larger populations; intense competition for limited resources so increased parental care and few offspring are favoured

Question 11

age structure

Answer 11

the number of individuals within each age group of a population

Question 12

what do ecologists use to understand past and predict future changes in populations?

Answer 12

ecologists use birth rates, expected longevity of individuals, and the proportion of individuals in a population that is able to reproduce

Question 13

estimating the number of individuals of differing ages enables ecologists to predict….

Answer 13

whether the size of a population will increase or decrease

Question 14

a growing population has what shaped distribution?

Answer 14

pyramid shaped distribution, larger young class than older class

Question 15

a stable population has a ______ distribution of age classes

Answer 15

even

Question 16

in humans, differences in age structures reflect….

Answer 16

socioeconomic variation among countries

Question 17

differences in age structure in other species reveal…

Answer 17

threats from various sources

Question 18

survivorship curves record changes in…

Answer 18

survival probability over an organism’s life-span

Question 19

demography

Answer 19

the study of the size, structure, and distribution of populations over time, including changes in response to birth, aging, migration, and death

Question 20

cohort

Answer 20

a group of the individuals born at a given time (usually group that we begin our studies with)

Question 21

life table

Answer 21

a table that presents information about how many individuals of a cohort are alive at different points in time (used to identify patterns of survival in population)

Question 22

survivorship

Answer 22

the proportion of individuals from an initial cohort that survive to each successive stage of the life cycle

Question 23

populations differ in the ages at which they experience the most ______

Answer 23

mortality

Question 24

survivorship curve Type I

Answer 24

most humans and other large mammals survive their early years and show a steep decline in the last part of their life-span

Question 25

survivorship curve Type II

Answer 25

small mammals and birds tend to lose numbers steadily throughout their lives

Question 26

survivorship curve Type III

Answer 26

many Turtle Grass seedlings and those of most other herbaceous plants DO NOT SURVIVE THE EARLIEST PERIOD of life, but those that do survive show only slow additional declines over time

Question 27

associate r-strategists with…

Answer 27

Type III survivor: r-strategists reproduce at rates approaching r, the intrinsic rate of growth

Question 28

associate K-strategists with…

Answer 28

Type I survivor: population densities commonly lie near the carrying capacity K, when resources become scarce

Question 29

r-strategists and K-strategists are on opposite ends of:

Answer 29

extremes-possible reproduction strategies in between can exist

Question 30

life history

Answer 30

the typical patter of resource investment in each stage of a given species’ lifetime

Question 31

control over allocation of energy resources involves :

Answer 31

physiological trade-offs

Question 32

the various ways in which animals and plants allocate resources to growth and reproduction is rooted in their:

Answer 32

physiological and their physiological traits are themselves, evolved traits