AP Environmental Science Quiz: Survivorship Curves

What this quiz covers

This quiz focuses on Survivorship Curves, giving you a quick way to practice the rules, question types, and explanations that matter most for AP Environmental Science.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. Type III
2. Type II (correct answer)
3. Type I
4. Type I (high early mortality)

Explanation: Survivorship curves represent different mortality patterns across age classes. Type I curves show low early mortality and high late-life mortality, forming a curve that remains high until old age then drops steeply. Type II curves demonstrate constant mortality rates across all ages, appearing as a straight, steadily declining line on a linear scale because the same proportion dies each time period. Type III curves exhibit high juvenile mortality followed by lower adult mortality, creating a steep initial drop then a flatter tail. A graph showing an approximately straight decline with age indicates constant probability of death at any age, which defines Type II survivorship.

Question 2

1. Type II (constant mortality at all ages)
2. Type III (high juvenile mortality, few survive to adulthood)
3. Type I (low early mortality, most die late in life) (correct answer)
4. Type I (high juvenile mortality, then stable survivorship)

Explanation: Survivorship curves describe how mortality rates change across an organism's lifespan. Type I curves show high survivorship through early and middle life, with most deaths occurring in old age - forming a convex curve that drops steeply at the end. Type II curves show constant mortality risk across all ages, creating a straight diagonal line. Type III curves show very high early mortality with improved survival for those reaching adulthood, forming a concave curve. Population X's pattern of high survivorship through early and middle life followed by steep decline in old age perfectly matches Type I survivorship, making C the correct answer. This pattern is typical of large mammals with extensive parental care, including humans and elephants.

Question 3

1. Type III
2. Type II
3. Type I (correct answer)
4. Type II (high juvenile mortality)

Explanation: Survivorship curves represent different mortality patterns across age groups. Type I curves are characterized by high survival rates with 90% of individuals surviving to adulthood due to parental care and protection, but then experiencing quickly dropping survivorship after a certain age due to senescence and age-related mortality. Type II curves show constant mortality across ages. Type III curves exhibit high juvenile mortality followed by lower adult mortality. The pattern described - high juvenile survival followed by rapid mortality increases after age 10 - is most consistent with Type I survivorship typical of species with parental investment.

Question 4

1. Type II
2. Type III
3. Type I (correct answer)
4. Type III (constant mortality)

Explanation: Survivorship curves represent different mortality patterns across age classes. Type I curves are characterized by extremely high survival for early and middle life stages, followed by a rapid increase in mortality late in life due to aging and senescence processes. Type II curves show constant mortality across ages. Type III curves exhibit high juvenile mortality followed by lower adult mortality. Laboratory fruit fly populations, like other species with extensive parental care or protected environments, often demonstrate high early survival followed by age-related mortality increases, which resembles the Type I survivorship pattern most closely.

Question 5

1. Type III
2. Type II
3. Type I (correct answer)
4. Type II (high early mortality, then low late mortality)

Explanation: Type I survivorship curves are characterized by low mortality rates during early and middle life stages, followed by a dramatic increase in mortality at older ages. This pattern is typical of species with extensive parental care, such as humans, other primates, and large mammals like elephants. The description explicitly states there is low mortality during early life due to parental care and medical intervention, with mortality increasing dramatically at older ages - this precisely matches the Type I pattern. Type II curves show constant mortality across all ages, while Type III curves show high early mortality followed by lower mortality for survivors. The combination of low early mortality and high late mortality definitively identifies this as Type I survivorship, making answer C correct.

Question 6

1. Type II (constant mortality across ages)
2. Type I (low juvenile mortality, high late-life mortality)
3. Type III (high juvenile mortality, lower mortality after maturity) (correct answer)
4. Type I (constant mortality across ages)

Explanation: The survivorship curve described for Species Y shows a steep drop between ages 0 and 1, followed by a much slower decline from ages 1 to 10. This pattern is characteristic of Type III survivorship, where there is very high mortality in early life stages (the steep drop between ages 0 and 1) followed by relatively low mortality for individuals that survive past the vulnerable juvenile period (the slower decline from ages 1 to 10). Type I curves would show high survival in early life, not a steep drop, while Type II curves would show a constant rate of decline throughout life rather than the two distinct phases described. The dramatic early mortality followed by improved survival for older individuals definitively identifies this as Type III survivorship, making answer C correct.

Question 7

1. Curve A
2. Curve C
3. Curve B (correct answer)
4. All three are Type II

Explanation: The question describes three distinct survivorship curves and asks which represents Type II survivorship. Curve A stays high until late life then drops sharply, which is the classic Type I pattern seen in humans and other large mammals with extensive parental care. Curve B declines at a nearly constant rate, which is the defining characteristic of Type II survivorship where mortality risk is constant across all ages - this creates a straight diagonal line on a semi-log plot. Curve C drops steeply early in life then levels off, which is the Type III pattern typical of species with high juvenile mortality but better survival once they reach adulthood. Since Type II is defined by constant mortality rates across the lifespan, Curve B correctly represents this pattern, making answer C correct.

Question 8

1. Type I (low early mortality, high late mortality)
2. Type II (constant mortality at all ages) (correct answer)
3. Type III (high early mortality, low mortality later)
4. Type II (high early mortality, then constant low mortality)

Explanation: Type II survivorship curves are characterized by a constant mortality rate throughout the lifespan, meaning individuals have roughly the same probability of dying at any age. This creates a straight diagonal line when plotted on a semi-log graph of survivors versus age. Many bird species, some lizards, and various small mammals exhibit this pattern where predation, disease, and other mortality factors affect all age classes relatively equally. Type I curves show low early mortality and high late mortality, while Type III curves show high early mortality and low late mortality. Since the songbirds experience the same chance of dying each year regardless of age, they clearly exhibit Type II survivorship, making answer B correct.

Question 9

1. Type II (constant mortality across ages)
2. Type III (high early mortality; few reach adulthood) (correct answer)
3. Type I (low early mortality; most die old)
4. Type II (low early mortality with steep late-life decline)

Explanation: Survivorship curves classify species based on age-specific mortality patterns. Type I species invest heavily in few offspring, providing care that ensures high juvenile survival, with most mortality occurring late in life. Type II species experience relatively constant mortality rates across all ages. Type III species produce many offspring with minimal parental investment, resulting in very high early mortality from predation and environmental stress, though adults that survive the vulnerable early stages tend to live relatively long. Species X, with many young dying quickly but adults living relatively long, clearly follows a Type III survivorship pattern.

Question 10

1. Type I (low early mortality; most die old)
2. Type III (high early mortality; few reach adulthood)
3. Type II (constant mortality across ages) (correct answer)
4. Type III (low early mortality followed by constant adult mortality)

Explanation: Survivorship curves categorize how mortality risk changes with age in populations. Type I curves show low mortality until old age, typical of species with extensive parental care. Type II curves exhibit approximately constant mortality rates across all age classes, creating a straight diagonal line when plotting log(survivors) versus age. Type III curves display very high early mortality followed by improved survival for mature individuals. This turtle species, with its constant chance of dying each year from steady bycatch and predation risks regardless of age, perfectly exemplifies Type II survivorship with uniform mortality across the lifespan.

Question 11

1. Type II (constant mortality across ages)
2. Type I (low early mortality; most die old)
3. Type I (constant mortality until old age)
4. Type III (high early mortality; few reach adulthood) (correct answer)

Explanation: Survivorship curves illustrate age-specific survival patterns in populations. Type I curves show high survival through juvenile and adult stages with mortality concentrated in old age. Type II curves display steady, constant mortality rates across all ages. Type III curves are characterized by extremely high mortality in early life stages due to predation, weather, and other environmental factors, with much better survival for individuals reaching maturity. This forest insect, laying hundreds of eggs with most larvae dying before the next life stage, exemplifies Type III survivorship typical of r-selected species that produce many offspring with minimal parental investment.

Question 12

1. 1: Type II; 2: Type I; 3: Type III
2. 1: Type I; 2: Type II; 3: Type III (correct answer)
3. 1: Type III; 2: Type II; 3: Type I
4. 1: Type I; 2: Type III; 3: Type II

Explanation: This question tests understanding of the three survivorship curve types through their defining characteristics. Description 1 states "most individuals survive to old age; deaths occur primarily late in life" - this is the definition of Type I survivorship with its convex curve. Description 2 states "individuals have a roughly equal chance of dying at any age" - this constant mortality rate defines Type II survivorship with its straight diagonal line. Description 3 states "many die young; those that survive early life often live much longer" - this high early mortality followed by better adult survival defines Type III survivorship with its concave curve. Answer B correctly matches these descriptions: 1 to Type I, 2 to Type II, and 3 to Type III, demonstrating proper understanding of each survivorship pattern.

Question 13

1. Type I
2. Type III (correct answer)
3. Type II
4. Type I (constant mortality)

Explanation: Survivorship curves illustrate three fundamental mortality patterns in populations. The student incorrectly attributes extremely high juvenile mortality with few reaching adulthood to Type II - this actually describes Type III survivorship. Type I curves show low early mortality and high late-life mortality. Type II curves demonstrate constant mortality rates across ages. Type III curves are characterized by extremely high juvenile mortality where most offspring die young and few individuals reach reproductive maturity. The student's description of high juvenile mortality with few survivors matches Type III survivorship, not Type II.

Question 14

1. Type I
2. Type II
3. Type III (correct answer)
4. Type I (constant mortality)

Explanation: Survivorship curves describe mortality patterns throughout an organism's lifespan. Type I curves show low early mortality and high late-life mortality. Type II curves demonstrate constant mortality rates across ages. Type III curves are characterized by extremely high juvenile mortality with only a small percentage (like 5%) of individuals surviving past the first critical period, but those that do survive the vulnerable early stages often live for years with much improved survival prospects. This pattern of massive early losses followed by better adult survival is most consistent with Type III survivorship.

Question 15

1. Type I
2. Type II
3. Type III (correct answer)
4. Type II (low early mortality)

Explanation: Survivorship curves represent different mortality patterns across age classes. Type I curves show low early mortality and high late-life mortality. Type II curves demonstrate constant mortality rates across ages. Type III curves are characterized by a sharp drop in the first life stage (egg/larva) due to high juvenile mortality from predation and environmental stress, followed by a much slower decline thereafter as surviving adults face fewer threats. This pattern of steep early mortality followed by improved survival for those reaching maturity defines Type III survivorship, common in insects and other species with high fecundity and minimal parental care.

Question 16

1. Type II
2. Type I
3. Type III (correct answer)
4. Type I (constant mortality)

Explanation: Survivorship curves describe mortality patterns throughout an organism's lifespan. The population ecologist correctly identifies three idealized patterns: late-life mortality (humans), constant mortality (birds), and high early mortality (fish/insects). Type I curves show low early mortality and high late-life mortality. Type II curves demonstrate constant mortality rates across ages. Type III curves are characterized by high early mortality where most offspring die young due to predation and environmental stress, typical of many fish and insects that produce large numbers of offspring with minimal parental care.

Question 17

1. Type II (constant mortality)
2. Type I (low early mortality, high late mortality) (correct answer)
3. Type III (high early mortality)
4. Type I (high early mortality, low late mortality)

Explanation: Survivorship curves describe three basic mortality patterns in populations. Type I curves show low mortality early in life due to parental care and protection, with mortality increasing sharply after reproductive years due to senescence. Type II curves exhibit constant mortality rates across all ages. Type III curves display high juvenile mortality followed by lower adult mortality. The described human population pattern - high survivorship through childhood and adulthood due to medical care and parental investment, followed by steep mortality increases after reproductive years - is the classic example of Type I survivorship found in developed human populations and other species with extensive parental care.

Question 18

1. Type III (high mortality early in life)
2. Type II (constant mortality across the lifespan)
3. Type I (low mortality early and midlife, high late-life mortality) (correct answer)
4. Type I (constant mortality across the lifespan)

Explanation: The key characteristics described - extensive parental care, few offspring per reproductive event, high survival to adulthood, and mortality increasing sharply only at older ages - are all hallmarks of Type I survivorship. Type I curves show low mortality during early and middle life stages, with most deaths concentrated in old age, creating a convex curve. Type II shows constant mortality across ages, while Type III shows very high early mortality. Mammals with extensive parental care invest heavily in each offspring, ensuring high juvenile survival rates typical of Type I patterns. Answer C correctly identifies this as Type I survivorship, which is characteristic of large mammals like primates, elephants, and whales that have K-selected life history strategies.

Question 19

1. Type III (high mortality early in life)
2. Type II (constant mortality across the lifespan)
3. Type I (low mortality early, high mortality late) (correct answer)
4. Type I (constant mortality across the lifespan)

Explanation: The public health data describes a classic Type I survivorship pattern: most people survive through childhood and adulthood with death rates increasing substantially only in late adulthood. Type I curves are characterized by low mortality during early and middle life stages, with most deaths concentrated in old age, creating a convex survivorship curve. Type II would show constant mortality across ages, while Type III would show very high childhood mortality. Developed countries typically exhibit Type I survivorship due to advanced healthcare, sanitation, and social safety nets that minimize early mortality. Answer C correctly identifies this as Type I survivorship, which reflects high parental investment and societal resources devoted to ensuring survival through reproductive years.

Question 20

1. Type II (correct answer)
2. Type I
3. Type III
4. Type I (high early mortality, then constant mortality)

Explanation: Type II survivorship is defined by a constant mortality rate across all age classes, meaning individuals have the same probability of dying regardless of their age. When plotted on a semi-log graph, this creates a straight diagonal line declining from birth to maximum lifespan. The lizard population described shows exactly this pattern - individuals of all ages from hatchlings through older adults are equally likely to be eaten by predators each month. This constant predation pressure across all ages is a textbook example of Type II survivorship. Type I curves would show low mortality in young individuals, while Type III curves would show very high mortality in young individuals, neither of which matches the described pattern, confirming answer A is correct.