Question 1

Which plant life history type, fast or slow, would best describe a weed species that is a good invader of new habitats?

Accepted Answer

The fast life history would foster the development and spread of an opportunistic weed species that can rapidly populate a new or disturbed habitat.

Question 2

Fecundity is

Accepted Answer

Fecundity refers to the number of offspring that an organism can produce per reproductive episode. It does not refer to the number of reproductive episodes, the overall energy expended, or the period of reproductive activity.

Question 3

Explain why life history variables, such as number of offspring, size of offspring, and degree of parental care, are often correlated.

Accepted Answer

Species cannot maximize all of these traits. For example, if many offspring are produced, they will probably be smaller than if few are produced. Parental care is much more effective with few offspring.

Question 4

Which of the following does NOT apply to determinate growth?

Accepted Answer

The answer of Which of the following does NOT apply...

Question 5

Which life history type do mammals exhibit?

Accepted Answer

Mammals typically exhibit a slow life history, characterized by longer gestation periods, fewer offspring, longer lifespans, and significant parental care compared to other organisms.

Question 6

Some marine snails (species L) produce large numbers of small eggs that are shed into the sea, hatch at an early stage of development, and feed on microscopic plants. Other marine snails (species S) produce few eggs that are retained for a long time within the body of the mother snail in a brood pouch, hatch at an advanced stage of development, and immediately begin to feed on the surfaces of large plants like the adults. If a biologist discovers approximately equal numbers of adults of species L and S in the same area over many generations, which of the following is most likely?

Accepted Answer

The answer of Some marine snails (species L) produce large...

Question 7

Topic: combinations of life history traits in plants
Difficulty: medium
Consider a species with a slow potential growth rate, reproduction at a relatively late age, allocation of a small proportion of net production to seeds, and reliance on vegetative spread. According to Grime's classification of life history traits, this species fits the profile of a:

Accepted Answer

Grime's classification of life history traits defines stress-tolerant species as those that have a slow potential growth rate, allocate little energy to reproduction, reach reproductive maturity at a late age, and rely on vegetative spread for reproduction. The given species fits this profile, as it has a slow growth rate, allocates a small proportion of net production to seeds, reproduces at a relatively late age, and spreads through vegetative propagation. Therefore, the best choice is A) stress-tolerant species.

Question 8

Which does NOT have fast life history attributes?

Accepted Answer

Albatrosses have slow life history attributes, with long lifespans, low reproductive rates, and delayed maturity.

Question 9

Explain the main life history trait that differentiates ruderals and stress-tolerant plants.

Accepted Answer

The answer of Explain the main life history trait that...

Question 10

Which of the following does NOT apply to indeterminate growth?

Accepted Answer

Indeterminate growth refers to growth in body size throughout life and a flexible age of maturation, which are both in contrast to determinate growth. It is a characteristic of plants and insects, but not exclusive to them. Semelparity, which refers to organisms that only reproduce once in their lifetime, is not directly related to growth patterns. Cessation of growth upon maturation is a characteristic of determinate growth, not indeterminate. Therefore, the correct answer is B.

Question 11

Which does NOT have slow life history attributes?

Accepted Answer

Slow life history attributes typically include large body size, long lifespan, late sexual maturity, low reproductive output, and high parental investment. Sea urchins have a relatively fast life history, with small body size, early sexual maturity, high reproductive output, and low parental investment.

Question 12

Some marine snails (species L) produce large numbers of small eggs that are shed into the sea, hatch at an early stage of development, and feed on microscopic plants. Other marine snails (species S) produce few eggs that are retained for a long time within the body of the mother snail in a brood pouch, hatch at an advanced stage of development, and immediately begin to feed on the surfaces of large plants like the adults. A biologist discovers approximately equal numbers of adults of species L and S in the same area over many generations. While studying the two species of snails, the biologist hypothesizes that the two species expend approximately the same amount of energy producing young. What assumption is the biologist making?

Accepted Answer

The biologist's hypothesis assumes that although species L and species S produce eggs with different characteristics, they both require the same amount of energy to produce. This means that the difference in their reproductive strategies is not due to differences in energy investment, but rather to other factors such as environmental pressures or resource availability. Therefore, option B, which suggests that an egg of species S contains more energy than an egg of species L, would not be in line with the biologist's assumption.

Question 13

How does having a large number of offspring affect a parent's fitness for subsequent breeding seasons?

Accepted Answer

In order to care for a large number of offspring, the parent must invest more energy and resources into feeding and raising them, which can reduce the parent's own survival and thus, lower fitness for subsequent breeding seasons.

Question 14

Grime proposed that combinations of life history traits in plants are mainly determined by three factors. Which is NOT one of these factors?

Accepted Answer

Grime proposed that combinations of life history traits in plants are mainly determined by three factors: disturbance, competition, and stress. Herbivory is not one of the main factors proposed by Grime.

Question 15

Which life history trait is most likely to be fixed for a species?

Accepted Answer

Timing of reproduction in the lifespan is most likely to be fixed for a species because it is closely tied to the species' evolutionary strategy and environmental adaptations, making it a consistent characteristic across individuals of the species.

Question 16

Topic: growth versus age of sexual maturity and life span
Difficulty: medium
For birds, age at maturity

Accepted Answer

Birds that have higher annual survival rates tend to mature later, as they have more opportunities to reproduce over a longer lifespan.

Question 17

The principle of allocation states that life history traits are adapted to maximize

Accepted Answer

The principle of allocation refers to the concept that organisms need to allocate limited resources towards different life history traits such as growth, reproduction, and survival. These traits are often in competition, and individuals may have to make trade-offs between them. Fitness is the ultimate goal of natural selection, and life history traits are adapted to maximize an organism's overall fitness. Therefore, choice A is the best answer.

Question 18

When adults have a high probability of survival from one year to the next and offspring survival is relatively poor, the best strategy for an adult to maximize fitness is to

Accepted Answer

When adult survival is relatively high compared to offspring survival, it is advantageous to prioritize survival over fecundity to maximize fitness. This means that adults should invest more resources towards increasing their own survival rather than having more offspring that may not survive to reproduce themselves. Therefore, the best strategy would be to increase survival at the expense of fecundity.

Question 19

Which life history type, fast or slow, is more likely to describe an endangered animal species?

Accepted Answer

The answer of Which life history type, fast or slow,...

Question 20

Topic: combinations of life history traits in plants
Difficulty: medium
Consider a species with a fast potential growth rate, reproduction at a relatively early age, allocation of a small proportion of net production to seeds, and reliance on vegetative spread. According to Grime's classification of life history traits, this species fits the profile of a

Accepted Answer

According to Grime's classification, a competitor species is characterized by fast growth, early reproduction, and reliance on vegetative spread, which matches the traits described for the species in question.

Quiz 8: Life Histories