Chapter 16 Exam Study Guide Questions

PLEASE answer these questions and definitions.

Chapter 16

1   Population ecology is the study of how populations interact with their environments.

      16.1 What is ecology?

      16.2 Why is a population perspective necessary in ecology?

      16.3 Explain why populations can grow quickly for a while, but not forever.

      16.4 Explain why a population's growth is limited by its environment.

      16.5 Why do some populations cycle between large and small?

      16.6 Explain why the "Maximum sustainable yield" is useful but nearly impossible to implement.

2   A life history is like a species summary.

      16.7 What are life histories shaped by?

      16.8 What are the trade-offs between growth, reproduction, and longevity?

      16.9 This is how we do it: Why does rapid growth come at a cost?

      16.10 How are populations described quantitatively?

3   Ecology influences the evolution of aging in a population.

      16.11 Things fall apart: what is aging and why does it occur?

      16.12 What determines the average longevity in different species?

      16.13 Can we slow down the process of aging?

4   The human population is growing rapidly.

      16.14 What do age pyramids reveal about a population?

      16.15 What happens when less-developed countries become more developed?

      16.16 Human population growth: how high can it go?

 

Key Terms

aging

carrying capacity, K

demographic transition 

density-dependent factors

density-independent factors

ecological footprint

ecology

exponential growth

growth rate

hazard factor

life history

life table

logistic growth

maximum sustainable yield

population density

population ecology

reproductive investment

reproductive output

survivorship curve

 

>16.1)Ecology:The study of how organisms interact with one another and with their physical environment.

>16.2)Population perspective is important in ecology because population can be used to develop population viability analysis which makes it possible to predict the long term probability of a species persisting in a given habitat.

>16.3)Populations cannot grow exponentially forever.Exploding populations always reach a size limit imposed by the shortage of one or more factors such as water,space and nutrients or by adverse conditions such as disease or drought.

>16.4)A population size is dependent on the carrying capacity of the environment and the intensity of density-dependent factors such as competition for resources which increase with population density increase,and can limit population size.

>16.5)Many populations exhibit periods of growth and decline due to cyclic changes in population growth caused by seasonal or environmental changes ,or driven by density -dependent processes such as predation.

>16.6)Multiple sustainable yield is important as it is the optimal strategy to harvest the most valuable life stage under existing environmental conditions. It cannot be implemented because of consistent variability in environmental conditions and species interactions such as predation.

>16.7)Life history is shaped by natural selection.

>16.8)Trade offs between growth,survival and reproduction:1)Number of offspring produced and the amount of energy put into each offspring in terms of physical resources and parental care.(2)Timing of first reproduction i.e early reproduction lowers the chance of dying without offspring.

>16.9)Rapid growth can cause antagonistic behavior and aggression among species which determine individual success under interference competition.

>16.10)Populations are described quantitatively by using quantitative characters,life history and population dynamics.

>16.11)Aging is the impact of time on human body,and can occur on multiple levels such as cellular aging.It is a gradual,continuous process of natural change that begins in early adult hood.Aging is caused biologically by the shortening of telomeres; however can also be caused by environmental factors such as ultraviolet rays,poor diet,and alcohol, as well as other psychological factors such as stress,which put the cells at damage.

>16.12)Factors that determine longevity in species:genes associated with blood fat, inflammation, cardiovascular and immune systems as the genes influence risk of heart diseases,stroke and insulin resistance.

>16.13)Ways to slow down aging:Decrease stress levels,add more physical activity,stay hydrated,eat natural food.

>16.14)Age pyramids:Reveals distribution of age groups in a population.

>16.15)Less developed countries would become more industrialized and have higher per capita income levels.

>16.16) Approximated human population growth to reach 9.7 billion by 20150.

>Aging:is the process of becoming older.

>Carrying capacity, K: The number of people, animals, or crops which a region can support without environmental degradation

>Demographic transition: is a model that describes population change over time.

>Density-dependent factors:Are limiting factors such as predation,which increase with the size of the population and limit growth as population size increases.

>Ecological footprint:Is a method promoted by the Global Footprint Network to measure human demand on natural capital.

>Ecology:The branch of biology that deals with the relations of organisms to one another and to their physical surroundings.

>Exponential growth:A type of growth whose rate becomes ever more rapid in proportion to the growing total number or size.

>Growth rate:the rate of natural increase is the difference between the birthrate and the death rate.

>Hazard factor:Any biological, physical, or chemical element that causes adverse responses in the environment

>Life history:Defines  the sequence of events related to survival and reproduction that occur from birth through death.

>Life table : A table which shows, details of an individual at each age, and the probability that they die before their next birthday.

>Logistic growth:Occurs when the rate of growth . decreases as the population reaches carrying capacity

>Maximum sustainable yield:The size of a natural population at which it produces a maximum rate of increase.

>Population density:The number of people per unit of area.

>Population ecology:The ecological study of how living and non-living factors influence the size,density, dispersion, and of a population.

>Reproductive investment: Refer to parental expenditure such as time; that benefits an offspring at a cost to parent's ability to invest in other components of fitness.

>Reproductive output:Refer to the average product of gamete abundance representing the reproductive effort of an individual. 

>Survivorship curve: A graph that shows the number of individuals surviving to a particular age for a given species or group of organisms.