chapter 19

Question 1

what are the two opposing forces that operate in the growth and development of populations

Answer 1

biotic potential–»ability to reproduce and survive at a given rate

environmental–»opposition to growth from biological, chemical and physical forces in nature

Question 2

what is exponential growth, what is logistic growth, what is carrying capacity

Answer 2

exponential–» J shaped curve—rate of growth of a population under ideal conditions, unregulated growth, cannot continue indefinitely because food supplies and space become limited and waste products build

logistic–» S shaped curve— population growth that is slowed by limiting factors— growth may start off exponential but it levels off at the carrying capacity of the environment

carrying capacity –» number of individuals that an environment can support for a prolonged period of time

Question 3

what are 3 ways an individual’s contribution to population growth can be increased, which is the most important

Answer 3

–»producing a larger number of offspring at a time

–»having a longer reproductive life

–»reproducing earlier in life.

Question 4

what are the characteristics of an r-selection strategy, what are the characteristics of a K-selection strategy

Answer 4

r-selection -->>
		typically reproduce once 
		have many young
		young are small
		young mature rapidly
		young have little or no parental care

K-selection-->>
		Typically reproduce more than once
		Have few young at a time 
		Young are larger 
		Younger mature more slowly
		Young have parental care, often intensive care

Question 5

what are some examples of density dependent and density independent factors that regulate population growth

Answer 5

density dependent–»
resource limitationsfood, space
predation–»predator more likely to encounter crowded prey population
intrinsic
factors–»high density leads to stress syndrome which can delay maturation or inhibit reproduction or suppress immunity

density independent-->>
	seasonal weather changes freezing in winter, heat in summer catastrophic weather events -->> floods, earthquakes, forest fires—severe enough to kill 50% of the population—large or small population

Question 6

what is the approximate human world population

Answer 6

2.5 billion

Question 7

what is the main distinction between an expanding population and a stable population

Answer 7

stable population–»about half of the human population is in developed countries that have completed the demographic transition

expanding population–» the other half of the human population is in underdeveloped countries that are stuck in the second stage of the transition where birth rates are still high