Processes of Population Change

Direct answer: B is correct. Internal migration means that people move from one part of the same country to another. The source region loses people and the destination region gains them, so the distribution of population changes. However, the people remain within the country, so the national total does not directly increase or decrease because of that movement. Option A involves people entering from another country, so it can increase the national total as well as alter distribution. Option C increases natural population change through more births. Option D can also increase total population by reducing deaths, but it is not migration. The key distinction is between redistribution inside a country and movement across national borders. Memory cue: internal migration relocates people; international migration changes the country total as well.

Direct answer: A is correct. Natural increase is calculated by subtracting deaths from births. If the death rate falls sharply while the birth rate remains high or falls more slowly, the gap between births and deaths becomes larger. More children and adults survive, so the population can grow rapidly in a short period. This is why a decline in mortality may accelerate growth even without any rise in births. Option B is the opposite of the demographic relationship and is not caused automatically by fewer deaths. Option C is not a necessary result; out-migration may rise, fall or remain unchanged. Option D confuses population growth with area, which does not determine how many people are born or die. Memory cue: fewer deaths with births continuing means a wider birth–death gap and faster natural increase.

Correct answer: A. The dependency ratio compares people usually outside the working-age group, especially children and older persons, with people of working age. When many working-age residents leave a source region, the number of workers falls. Even if the numbers of children and older persons do not change, they become a larger proportion of the remaining population. This can increase the relative burden on the remaining workers, families, and public services. A is correct because it describes this change in population composition. B is wrong because migration does not make the birth rate always zero. C is wrong because the question says working-age people leave, not all elderly people. D is wrong because a census may still be conducted; data collection is not the cause of the ratio change. Memory cue: fewer workers with the same dependants means a higher dependency ratio.

Correct answer: A. Infant mortality is the number or rate of infant deaths in a population. When health care, nutrition, sanitation, or protection improve, more children may survive. If families continue having roughly the same number of births for some time, the number of surviving children rises before birth behaviour changes. This time gap can initially increase natural population growth. A is correct because it describes this temporary or early effect without claiming that it must continue forever. B is wrong because lower infant mortality does not immediately stop births. C is unrelated: migration remains movement between places. D is wrong because better survival does not necessarily make the total population decline. Later, families may revise their desired family size, so the growth pattern can change. Memory cue: survival may change first; fertility behaviour often responds later.

Correct answer: A. Birth rate is a population measure showing the number of live births in relation to the population during a given period, often expressed per thousand people per year. It is not determined only by biology or physical geography. Social conditions such as the usual age at marriage, education, access to information and health services, ideas about family size, and the status of women can influence when and how many children families have. A is correct because it gives genuine social influences. B is wrong because river flow does not alone decide births. C is too absolute; birth rate and death rate are different measures, but both are parts of population change and may be studied together. D confuses a rate with area. Memory cue: birth rate reflects people’s reproductive behaviour within a social and economic setting.

Correct answer: A. Age structure means the distribution of a population among age groups, such as children, working-age adults, and older persons. It is important because a large young population may contribute to future births as it enters reproductive ages, while a large older population may increase the need for health care and support. The proportions of working-age and dependent groups also help us understand dependency and planning needs. A is correct because it names two direct uses of age structure: estimating future birth potential and understanding dependency. B concerns physical geography, not population composition. C confuses land area with people. D concerns weather and does not measure demographic structure. Memory cue: age structure helps answer who is present now and what population needs may arise later.

Correct answer: A. Comparing two census totals can show whether the population increased, decreased, or remained nearly stable between two dates. However, the totals alone do not explain how the change occurred. To understand the causes, we must examine births, deaths, and migration, and where relevant the age structure and other demographic conditions. A is correct because asking for causes requires more information than the two final totals provide. B is wrong because two numbers may be sufficient for a simple numerical comparison if only the final change is needed. C is not a reason for incompleteness; if there are truly no births, deaths, or migrations, the population process would be very limited. D is wrong because a fixed boundary can make comparison clearer, although it does not explain causes. Memory cue: census totals show the result; demographic processes explain the result.

Correct answer: A. Population size changes through natural processes—births and deaths—and through migration—people entering or leaving. If the number added by births and in-migration is equal to the number removed by deaths and out-migration, the total population can remain nearly unchanged. This is a balance of flows, not proof that nothing is happening. A is correct because it describes active processes whose net effect is zero. B is wrong because it describes an absence of two processes, and it says nothing about migration. C is wrong because people may move even when the total population is stable. D is conceptually incorrect: area and population are different measurements. Memory cue: a stable total can hide movement; always ask what is happening behind the final number.

Correct answer: A. Improvements in health care, sanitation, nutrition, and disease control can reduce the death rate. If the birth rate does not fall by the same amount at the same time, the difference between births and deaths—natural increase—becomes larger. Thus the logical sequence is health improvement, lower mortality, and higher natural growth. A is correct. B begins with a rise in death rate but then claims health improvement and higher life expectancy, so its order and relationships are inconsistent. C is contradictory because it starts with zero migration and then refers to high in-migration; in-migration would add people to the destination, not directly describe loss from the source in the same place. D is wrong because increasing area does not cause a zero birth rate or a population explosion. Memory cue: better survival can first increase natural growth when fertility changes more slowly.

Correct answer: A. Young people often form an important part of the reproductive-age and working-age population. If many of them leave a state, fewer people may remain in age groups that could produce births in the future. This can reduce the state’s future birth potential and may also alter its age structure and dependency pattern. A says “may,” which is appropriate because the result depends on the number, sex composition, duration, and later return or replacement of migrants. B is wrong because out-migration does not automatically cause in-migration. C is impossible as a general conclusion; migration cannot make the death rate always zero. D is wrong because people leaving cannot immediately double the total population. Memory cue: when young adults leave, look ahead at the age structure and future births, not only at today’s population total.

Correct answer: A, rapid rural-to-urban migration. A source region is the place from which people leave, while a destination region is the place where they settle. When many rural residents move to a city, the village may lose working-age people, labour, consumers, or family members, although it may receive remittances. The city may gain workers, skills, and consumers, but its housing, transport, water, sanitation, schools, and health services may face additional pressure. Thus, the same movement produces different effects in the two places. B is incorrect because equal births and deaths do not describe a different source and destination effect. C is incorrect because without migration there is no migration-related difference. D is incorrect because unchanged area does not explain population movement or its consequences. Memory cue: source sends people; destination receives people.

Correct answer: A. Regional imbalance means that population change is not similar in all regions. If some regions receive many migrants while other regions lose many people through out-migration, the receiving regions may grow faster and the losing regions may grow slowly or decline. The difference between them therefore becomes larger. Births and deaths also affect population, but the conditions in B and C state only that one rate is equal; they do not necessarily create the strongest regional contrast. D is incorrect because no migration removes this particular source of regional difference, although regions could still differ in births and deaths. To solve the question, compare the direction of movement: in-migration adds people to one place, while out-migration removes people from another. Memory cue: opposite migration directions widen regional gaps.

Correct answer: A. A decline in the death rate, especially when people survive to older ages, can increase the number and proportion of elderly people. Population ageing means that older age groups form a larger share of the total population. Better survival does not mean that every person becomes old at the same time; rather, more people reach advanced ages and remain alive for longer. B may change the local age composition through migration, but it is not the direct meaning of a declining death rate. C usually keeps the younger share large and therefore does not explain ageing. D is irrelevant because ageing can result from survival patterns even when migration has little or no effect. Remember that ageing is about the proportion of older people, not merely the total population. Memory cue: lower mortality plus longer survival can raise the elderly share.

Correct answer: A. Total population change may be understood by considering births, deaths, in-migration, and out-migration together. Births and in-migration add people to a population, while deaths and out-migration remove people. In simple form, change equals births plus in-migration minus deaths minus out-migration. If all four processes occur, ignoring any one of them can give an incorrect picture of whether the population is growing or declining. B includes only one component and therefore cannot represent a complete situation. C concerns land area, not a direct component of population change. D excludes two important components, so it cannot require all four. The formula is a checking tool, not a reason to assume that every place has equal values. Memory cue: add births and arrivals; subtract deaths and departures.

Correct answer: A. In-migration brings people into a city. New workers can fill jobs, support businesses, increase production, and add skills and demand, creating economic opportunities. However, if housing, water, sanitation, transport, schools, hospitals, and other services do not expand sufficiently, the growing population can produce overcrowding and pressure on urban facilities. The same process can therefore bring benefits and difficulties at the same time. B is incorrect because no arrivals mean no in-migration. C describes out-migration, not in-migration. D is unrelated to the central condition and is an extreme statement that does not explain the two-sided urban effect. A balanced answer must mention both the gain in labour or economic activity and the shortage of services. Memory cue: migrants may add workers but also add demand.

Correct answer: A. Family welfare programmes often aim to influence decisions about family size, timing of births, spacing between children, and the use of health or contraceptive services. These decisions are connected with education, awareness, family attitudes, access to services, income, customs, and personal choice. Such social and behavioural changes usually take time to spread through households and communities. Even after a programme begins, children already born remain part of the population, so the overall population pattern does not change instantly. B is incorrect because a programme does not necessarily make the death rate rise. C is unrelated: migration stopping is not the reason birth behaviour changes slowly. D concerns area, not reproductive decisions. Memory cue: policies may start quickly, but social behaviour changes gradually.

Correct answer: A. Natural increase is the difference between births and deaths. It does not include migration. Therefore, a place may have only a small excess of births over deaths, giving it a low natural increase rate, but still receive a very large number of migrants. Those arrivals can make the total population grow rapidly. B would generally reduce the population because people are leaving. C describes negative natural change with no migration, so rapid total growth would not follow. D gives no natural increase and no migration, so it cannot produce rapid growth through these components. Always separate natural increase from total population change: total change also includes the balance between in-migration and out-migration. Memory cue: natural growth is births minus deaths; total growth also counts movement.

Correct answer: A. High natural increase means that births are greater than deaths, so the population grows through natural processes. If schools, hospitals, teachers, doctors, water supply, and other services do not grow at a similar pace, the same facilities must serve more people. As a result, the amount or quality of service available to each person may decline, producing per-person pressure. B would generally reduce pressure because services are increasing faster than the population. C indicates zero natural increase, so it does not describe high natural increase. D may reduce the population through net out-migration and therefore does not necessarily create the stated pressure. The key is to compare the rate of population growth with the rate of service expansion. Memory cue: more people with unchanged facilities means less service per person.

Correct answer: A. Population change is influenced by social as well as biological conditions. Education can improve awareness, broaden choices, and influence decisions about marriage, family size, birth spacing, and the use of health services. Health conditions, medical care, nutrition, sanitation, and disease control can influence survival and therefore the death rate. Studying both indicators gives a fuller understanding of why birth and death patterns change. B is incorrect because education and health are social indicators, not measures of area. C is incorrect because neither one makes migration impossible; educated and healthy people may still move. D is incorrect because these factors do not stop population counting. The two indicators affect different but connected demographic processes. Memory cue: education influences birth decisions; health influences survival.

The correct answer is A: consider the time interval when comparing two periods. Population change means the difference between population at the beginning and at the end of a stated period. First identify both dates, then subtract the earlier population from the later population. If needed, divide the change by the number of years to find an average annual change. For example, an increase of 10,000 people in one year is much faster than the same increase over ten years. A is correct because comparisons require a common time basis. B is unrelated to population measurement. C concerns area, not duration. D is a map activity and gives no information about population change. Memory cue: change must always be linked to “how much in how much time.”

The correct answer is A: a sudden rise in outside population shows rapid in-migration into the city. Local migration patterns tell planners where people are arriving from, how quickly numbers are changing, and which services may need expansion. The city may require additional housing, water supply, sanitation, transport, schools, health centres and employment planning. A is therefore the only option that describes a strong local population movement needing regional policy. B provides no migration pattern to study. C describes equal vital events but says nothing about movement between places. D is too broad because a national average can hide important differences between cities and districts. Memory cue: local migration requires local planning.

The correct answer is A. A fall in infant mortality means more children survive, but parents may continue to follow older ideas about having a larger family. Beliefs about family size, the preferred number of children, marriage age, education, income security and access to health services do not change instantly. Consequently, birth rates may remain high for some time and then decline gradually. A correctly describes this social delay, often called a lag effect. B would produce a rapid fall rather than a slow one. C is contrary to the meaning of lower infant mortality. D concerns migration and does not directly determine birth decisions. Memory cue: survival can improve before family-size behaviour changes.

The correct answer is A. High birth rates add many people, a low death rate means more people remain alive, and rapid in-migration adds people from other places. When all three occur together, population may grow quickly and planners must respond to several demands at the same time. They may need more schools, hospitals, housing, jobs, transport, water and sanitation, while also estimating future needs. A is correct because it combines three population-change processes that increase pressure. B reduces one source of increase. C describes no deaths and no migration but does not state high births; it is not the strongest or complete condition. D changes physical area, not population processes. Memory cue: births add, deaths remove, migration redistributes or adds people.

The correct answer is A. If migration is mainly undertaken by male workers, the number and proportion of males may rise in the destination area and fall in the source area. This changes the sex composition, even though the total population change may be described simply as migration. Such a movement can also affect household responsibilities, the available labour force and the balance between people of different ages and sexes. A is correct because it identifies sex-selective migration. B has no migration effect. C compares births and deaths but does not show that one sex is moving more than another. D concerns area, not gender composition. Memory cue: ask not only “how many moved?” but also “who moved?”

The correct answer is A. Labour availability means the number of people who can work. When many working-age residents leave a rural area for cities, the source village may have fewer people available for farming, construction, local businesses and other activities. This is called out-migration from the rural source area. A is correct because it directly removes workers from the local labour pool. B adds children, who may not immediately be part of the working population. C improves living conditions but does not itself remove workers. D generally means more people survive and is not a direct cause of labour loss. Memory cue: out-migration reduces the source area’s workforce; in-migration adds to the destination’s workforce.