bio for the informed citizen - ch. 18
Carrying capacity
A certain town reached the maximum number of squirrels that can its environment can sustain. What is that number called? a. Environmental capacity b. Full capacity c. Carrying capacity d. None of these
A snapshot of a population at a given point in time: displays the number of individuals in age categories The age pyramid has separate sides for males and females, and each bar on the pyramid shows the number of individuals in a given five-year age class. Thus, an age pyramid shows both the sex ratio and age structure of a population. Age pyramids fall into three shape categories. Typically, the age pyramid is widest at the bottom, since children usually are the largest age group, and narrows toward the top due to mortality. Other shapes are possible, however, including reasonably vertical sides for the non-elderly age classes, as well as a tapering bottom that is narrower than the top. Properly interpreted, the shape of an age pyramid tells us a great deal about conditions in a country and the social challenges it is likely to face.
Age pyramid
Explain what age pyramids can tell us about a country's conditions and social challenges. • Demography is the study of population growth based on its age structure. • Females have a greater impact on population growth than males, and it varies based on their age. • An age pyramid shows the demographics of a population, both the sex ratio and age structure. • There are three possible shapes to age pyramids that describe conditions in a country and allow comparisons between countries: 1. Widest at the bottom shows that children are the largest group, and the number of individuals declines due to mortality associated with aging. 2. A tapering bottom, narrower than the top, indicates an aging population with a low birth rate. 3. Comparatively vertical sides suggest a stable growth rate and good longevity.
How Is Population Growth Influenced by Age and Sex?
We can opt to slow our growth
How is our population growth unlike bacterial growth? a. Bacteria reproduce sexually b. We can opt to slow our growth c. Bacteria can opt to slow their growth rate d. An open field of grasses and wildflowers
.06
If the birth rate in a particular country is .06 and the death rate is .01, what is the growth rate? a. .05 b. .06 c. .07 d. .01
10%
In Kenya, adding 1 year of education to a woman's life reduced the likelihood of teenage birth by what percentage? a. 20% b. 15% c. 5% d. 10%
48
In developing countries, how many infants out of every 1000 die before their first birthday? a. 48 b. 38 c. 28 d. 18
A growth pattern that proceeds at the same rate over a given time frame
Linear growth
A pattern of population growth that takes density dependence into account: starts off exponential and stops when the population reaches carrying capacity. on a graph, you would see the slow linear phase of growth and then the sharp rise of the exponential growth, and then you should see a leveling off at carrying capacity. The leveling off point is considered the logistical growth phase
Logistic growth
The maximum number of individuals the environment can support. The population starts off growing exponentially, but eventually, growth slows density-dependent factors reduce the growth rate. A second result is that as birth rates go down and death rates go up, there must be a point at which they are equal. When the growth rate is zero, the population is in equilibrium and its size does not change. This unchanging population size has a name—the carrying capacity. You can think of carrying capacity as the maximum number of individuals the environment can "carry," or support.
Carrying capacity
The scientists analyzed DNA from these subjects and discovered that they had a mutation in a gene called CATSPER1. The CATSPER1 gene makes a protein that is found on the flagellar "tail" of sperm cells. When a sperm cell encounters an egg, its tail begins to wiggle violently, a process known as hyperactivation. Hyperactivation is required for the sperm to get through the egg's outer membranes for fertilization. The CATSPER1 mutation prevented the sperm cells from hyper-activating, so they could not fertilize the egg.
Catsper 1 Mutation
A principle that underlies exponential growth: occurs its new entities are themselves capable of creating new entities. The principle that underlies exponential growth is compounding. In any growth process, new entities are added to the population. Compounding occurs if the new entities are themselves capable of making still more new entities. Any compounding growth process can grow exponentially. Without compounding, new entities contribute to the growth just by being there, but they do not themselves make more new entities.
Compounding
10
The US Constitution requires that a census be taken at least every how many years? a. 10 b. 15 c. 20 d. 25
A state when the population size does not change. You can think of growth rate as having two positive components (birth and immigration) and two negative components (death and emigration). The growth rate is the "balance" among these four components. If the positive components outweigh the negative, the growth rate is positive and the population grows exponentially. However, if the negative components outweigh the positive, population growth is negative and the population gets smaller. If birth and immigration exactly equal death and emigration, the growth rate is zero. When this occurs, the population is in equilibrium and its size does not change. As we will see later in the chapter, countries show a variety of growth rates. Many developing countries have large positive growth rates, while many European countries have negative growth rates.
Equilibrium
24 billion
Experts have projected the human population to reach 12 billion by 2040. How many humans are projected by 2080? a. 24 billion b. 20 billion c. 18 billion d. 16 billion
a growth that proceeds at an increasing rate over a given time frame. Exponential growth starts very slowly but then rapidly increases, always sharply curving upwards in the most recent day
Exponential growth
2
For human population growth to be zero, what does total fertility need to be? a. 2 b. 0 c. -2 d. 1
How fast a population grows. The growth rate tells us how fast a population grows. It also tells us how many people are added to the population during a year (or another appropriate period of time). To figure out how many people are added, just multiply the population size by its growth rate. Let's work through an example. Suppose a population starts with 1000 individuals ( N sub o ) and grows at 5% per year( r = 0.05). How big will the population be in 50 years ( t )? Multiply r by t, raise e to this power, and multiply by N 0 . The answer you get is 12,182 individuals, a 12-fold increase in 50 years.
Growth rate
Distinguish between linear and exponential growth and explain how the growth rate is determined. • Populations grow when new individuals are added; if this is the result of migration, the growth rate is linear, but if the individuals added reproduce, the growth is compounded, and the population grows exponentially. • Growth rate addresses two questions: How fast will it grow? How big will it get? • Population growth rate is calculated by adding births and immigrations and subtracting deaths and emigrations; a population is in equilibrium when the increase equals the decrease. • Doubling time is the amount of time required for a population to double in size.
How Can Populations Grow So Fast?
Females have greater impact
Who has the greatest impact on population growth? a. Both males and females have equal impact b. Males have greater impact c. Females have greater impact d. Neither males nor females have any impact.
Compare and contrast the factors that contribute to growth in developing and developed countries. • Total fertility is the number of children a woman could have, on average; birth rate is the average number she does have. • A total fertility of two would just replace the parents and result in zero population growth (ZPG). • Age at first reproduction is when women fi rst reproduce, and it tends to be later in life in more developed countries. • Developing countries tend to have both higher total fertility rates and lower ages of first reproduction, resulting in faster population growth. • Countries undergo a demographic transition as they develop.
Why Do Developing and Developed Countries Grow Differently?
Describe the effects of population density and carrying capacity on the principle of logistic growth. • Density-dependent factors—insuffi cient resources, waste production, disease, and aggression—eventually inhibit exponential growth. • The density-dependent factors result in logistic growth for most populations; growth starts out fast, slows as the population becomes larger, and stops as it reaches carrying capacity ( s -curve on a graph).
Why Don't Populations Grow Forever?
Children are usually the largest age group
Why are age pyramids typically widest near the bottom? a. The elderly are usually the median age group b. Children are usually the smallest age group c. The elderly are usually the largest age group d. Children are usually the largest age group
Since we are a globally mobile species, migration can also affect a country's population growth. Like birth and death rates, migration breaks down into two components: immigration (those moving in) and emigration (those leaving). Like the birth rate, immigration adds to a population, and like the death rate, emigration subtracts from it. If we take migration into account, we get our final formula for the growth rate: growth rate = (birth rate − death rate) + (immigration rate − emigration rate)
immigration/emmigration + growth rate
In a population, birth rate is the number of babies born per capita, and death rate is the number of deaths per capita. The (net) growth rate is the birth rate minus the death rate. Consider an example 5 babies are born and two people die: growth rate = (birth rate − death rate) = (5/100 − 2/100) = 0.03
natural growth rate
Home to nearly 20% of the world population China has implemented dramatic population control measures
population control measures
birth rate + death rate - immigration + emmigration -
what are the four factors of growth rate?
exponential growth
what is a fundemental property of all populations
Natural Growth Rate
what is growth rate called if you just factor in the birth and death rate?
exponential growth
what type of growth does a onecelled organism like bacteria have?
Demonstrate how data on population growth can be used to plan for population shifts and resource depletion. • Demographic information is necessary for anticipating shifts and planning government and resource allocation accordingly. • The U.S. Census Bureau provides detailed information about the demographics and number of people living in the United States. • The age pyramid at any given time allows predictions to be made about demographic shifts in the future. 1. Uganda has a lot of children, so its population will increase and the country will need to provide care for children and, eventually, jobs. 2. Italy's population is much older, so they will need to plan to support a retiring workforce with fewer younger workers. • As countries develop, they increase their use of limited resources, so it's important to plan accordingly by developing new resources or minimizing consumption.
How Do We Use Information About Population Growth?
All of these
Which of the following is responsible for the difference in growth rates between developed and developing countries? a. Age b. Nutrition c. Women's rights d. All of these
Older people are more susceptible to disease
Which of the following is a way in which age affects growth rate? a. Older people are more susceptible to disease b. Older people have more children c. Younger people have fewer children d. None of these
A physical altercation over access to water in a region
Which of the following is a density dependent conflict? a. A physical altercation over access to water in a region b. A violent reaction between two elements of different densities c. An attack that occurs as retaliation for an earlier attack d. None of these
all of these
Which of the following is a potential outcome of overpopulation? a. Resource depletion b. Increased waste c. Political instability d. All of these
The change in population growth patterns seen over time as developing countries become developed countries Over time, developing countries become developed countries. Industrialization occurs, urbanization increases, and the number of people working on farms decreases. Education becomes more important as children become a less important part of the labor force. Demographic factors also change, a process known as the demographic transition. Demographic transition divides a country's history into several stages: pre-development, transitional, and developed. During the PRE-development stage, the country experiences very high birth and death rates. These populations live close to their carrying capacity, and overall population growth is limited. The TRANSITION begins when the country starts to develop due to improved agriculture and increased interaction with developed countries. This interaction can lead to better medical practices, more sanitation, a cleaner water supply, more technology, and better education, which increases the carrying capacity. The death rate drops rapidly, as more children survive and life expectancy increases. Since birth rates at first remain constant, population growth increases in an exponential fashion. Toward the end of the transition, birth rates drop to match death rates. Urbanization increases, the status of women improves, access to contraception reduces the number of births, and women tend to postpone childbirth well past puberty. In time, population growth levels off and eventually stops. In some cases, the birth rate may drop below the death rate, causing the population to shrink.
Demographic transition
The science analyzes population growth by examining a population's age structure and how age affects fertility, survival, and population growth.
Demography
All of these
Demography analyzes how age affects which of the following? a. Fertility b. Survival c. Population growth d. All of these
a factor responsive to population crowding. As a population grows larger, it begins to have a negative impact on its environment and on its members. The amount of food and space available to each individual decreases, and waste products and pollution increase. Diseases and parasites spread more easily. Close contact among individuals may lead to aggressive conflicts. Factors like these are called density-dependent, because they grow worse with density, or crowding. Density-dependent factors make it harder for individuals to reproduce and less likely that individuals will survive as population size increases.
Density-dependent
A true environmental visionary - In 1972 Meadows, Forrester, and others published a seminal book, The Limits to Growth, in which they explain exponential and logistic growth. They simulated the growth of almost every important aspect of the world economy using system dynamics and reached a startling conclusion: "If the present growth trends in world population, industrialization, pollution, food production, and resource depletion continue unchanged, the limits to growth on this planet will be reached sometime within the next hundred years. The most probable result will be a rather sudden and uncontrollable decline in both population and industrial capacity." She brought to the world's attention the fact that we would not survive unless we started living in a sustainable manner.
Donella meadows
The amount of time required for a population to double in size. This doubling time depends only on the growth rate, not on the population size. To calculate doubling time, divide 0.69 by the growth rate (0.69 is the natural log of 2 and is a numerical constant used in calculations of exponential growth): doubling time = 0.69/growth rate Doubling time often gives a clearer and more intuitive interpretation of population growth than does the growth rate. For example, Table 18.1 shows that in 2010, the growth rate for the United States was 8.3 per 1000 individuals, or 0.0083—neither number is easily visualized. The doubling time makes more sense. At this rate of growth, the U.S. population would double in 0.69/0.0083, or 83 years. For comparison, Kuwait's population doubles in only 19 years. Doubling times can be meaningful for social planning purposes, such as deciding how many schools an area needs and how quickly they must be built.
Doubling time
Age pyramid
Which of the following is a tool for showing an age 'snapshot' of a population at a given time? a. Age photo b. Age pyramid c. Age meter d. Age web
Pubescent
Which of the following is not a lifestyle stage through which women go? a. Pre-pubescent b. Reproductive c. Pubescent d. Menopausal
The number of children a woman COULD have, on average, if she lived at least until the end of her reproductive use (birth rate is the total number of children a woman DOES HAVE). As we have seen, population growth rates can be negative, zero, or positive. Total fertility provides similar information. If total fertility is 2, then each couple exactly replaces itself with children. We can call this zero population growth (ZPG). If total fertility is more than 2, each couple more than replaces itself, and population size increases. If total fertility is less than 2 the population size decreases. A second important demographic factor is the age at first reproduction. This refers to when women actually give birth to their first child, not the age of puberty. Women in developed countries tend to bear children later in life. This works to reduce population growth in several ways. First, a woman who postpones having children may not live to have as many. Second, postponing childbirth reduces the number of generations alive at any one time. If people live to see their great-grandchildren, then four generations are alive at once. Developing countries have a much higher total fertility rate than developed ones. Uganda has a total fertility rate of 6.06 children per female, the fourth highest in the world. This compares to 2.06 and 1.41 for the United States and Italy, respectively. If we consider developing countries as a group, their total fertility is notably higher than that of developed countries. In developing countries, about 48 of each 1000 infants die before they reach their first birthday, while in developed countries, 6 infants out of 1000 on average suffer this fate. In developing countries, bearing more children is a safety net to ensure that at least some of your offspring survive.
Total fertility
Linear growth is a growth pattern in which there is a fixed and even measure of growth over a period of time. It could be increasing or decreasing, but it follows a linear pattern. exponential growth follows the mathematical concept of duplication in which it starts of slowly looking almost linear, but over time, because of the doubling concept there will eventually come a place when the curve appears to go straight upwards logistic growth is the growth period that generally follows after a population has hit its carrying capacity. logistic growth has a bit of an s shape to it as the population ebbs and flows to maintain equilibrium around that carrying capacity.
What are the differences between Linear growth, exponential growth, and logistic growth?
a. Birth rate, death rate, immigration rate, and emigration rate pg. 537
What are the four factors that determine a population's growth rate? a. Birth rate, death rate, immigration rate, and emigration rate b. Birth rate, death rate, compounding, and immigration rate c. Birth rate, death rate, doubling time, and compounding d. Birth rate, death rate, doubling time, and carrying capacity e. Birth rate, death rate, carrying capacity, and emigration rate
Reduce consumption below the level of exponential growth
What can people do to avoid reaching peak oil? a. Create more oil b. Reduce consumption below the level of exponential growth c. Maintain current consumption levels d. Peak oil is a myth
They both increase at a compounding rate.
What do population growth and credit card interest have in common? a. They both show linear growth. b. They are both easy to control. c. They both increase at a compounding rate. d. Nothing
e. Sex ratio and age structure of a population. pg.543
What information is shown in an age pyramid? a. Exponential growth and logistic growth b. Carrying capacity and sex ratio c. Logistic growth and age structure d. Demography and sex ratio of a population e. Sex ratio and age structure of a population
c. The maximum number of individuals an environment can support. pg.541
What is carrying capacity? a. Logistic growth that starts off fast but slows down as the population gets larger b. Exponential growth c. The maximum number of individuals an environment can support d. Growth rate e. The minimum number of individuals an environment can support
b. A principle that underlies exponential growth and that occurs when new entities are themselves capable of making more new entities pg. 534
What is compounding? a. A principle that underlines linear growth b. A principle that underlies exponential growth and that occurs when new entities are themselves capable of making more new entities c. A principle that underlies demographic transition d. A principle that underlies population density e. A principle that underlies logistic growth
Compounding
What is it called when new entities are themselves capable of still more entities? a. The copy principle b. Negative growth c. Linear growth d. Compounding
Peak oil
What is the point at which oil consumption begins to drop called? a. Oil drop b. Oil fall c. Peak oil d. Oil crest
Demographic transition
What is the shift in demographics that accompanies development called? a. Demographic shift b. Demographic transition c. Gradual transformation d. None of these
linear
What kind of growth does a straight line on a graph represent? a. Exponential b. Linear c. Compounding d. Negative
11%
What percentage of the world population does not have access to clean drinking water? a. 11% b. 12% c. 13% d. 14%
eventually 1. there is not enough resources to support the population 2. food and space are limited 3. there is nowhere to dispose of waste 4. disease and parasites become a problem 5. overcrowding leads to conflict 6. these situations increase death rates and make it difficult to reproduce the factors described above are all factors that are DENSITY DEPENDANT factors, meaning they happen as a result of increased density. in these situations, the decreasing birth rates and increased mortality rates serve to bring the population back down to a size which can be supported (hopefully)
What stops the population from growing indefinitely
Shoe size (seriously ?)
Which of the following does the Census NOT keep track of? a. Shoe size b. Age c. Ethnicity d. Employment status
