Q&A Hero

Q: Most r-selected species are small and short lived.

Q: The intrinsic rate of growth of a population is calculated by adding the death rate and the birth rate.

Q: The intrinsic rate of increase of a population is usually referred to as "r."

Q: The carrying capacity of an environment can cause a population initially growing very quickly to level off, resulting in an S-shaped curve.

Q: Arithmetic growth will produce a faster population increase over time than an exponential growth curve.

Q: A population that grows by an unvarying number of new units added to the population per unit of time is undergoing exponential growth.

Q: A community of organisms and the physical environment with which they interact is an ecosystem.

Q: All the members of a single species of frog in a particular pond would be an example of a population.

Q: The job of an ecologist is to preserve the natural world.

Q: A country's fertility rate suggests zero population growth, but it shows an increase of 2030 percent over 50 years. What might account for this? A) better food availability B) a larger proportion of post-reproductive females C) higher environmental resistance D) lower logistic growth E) immigration

Q: Ecologists often say that one individual living in a developed country cannot be counted as ecologically equal to one individual from a developing country because: A) the fertility rates are the same. B) the use of natural resources per person is different. C) r is different. D) K is different.

Q: Which is true of predictions about the expected population of the United States in the year 2050? A) The U.S. population will exceed 1.5 billion. B) Immigration is not expected to have a large effect on the U.S. population. C) The population is expected to grow about 43 percent. D) Emigration is expected to have a large effect on the U.S. population.

Q: What would be logical to conclude about a country with a population pyramid having a disproportionately large number of individuals in the 1544 year old range? A) The country is a developed country. B) The country will exhibit little population growth. C) The country will exhibit large population growth. D) The country will exhibit zero population growth.

Q: What would be a reasonable conclusion about a country with a fertility rate of about 1.6? A) The population will grow at a yearly rate of 1.6 percent. B) The population is likely to shrink. C) Zero population growth will occur. D) It must be a relatively young population.

Q: A population with a fertility rate of 2.1 will: A) slowly shrink. B) slowly grow. C) double each generation. D) decrease by half each generation. E) exhibit zero population growth.

Q: From the time of the industrial revolution until about 50 years ago, the human population growth rate most closely resembles: A) linear growth. B) exponential growth. C) variable, unpredictable growth. D) fluctuating increases and decreases, with overall slow growth.

Q: You are doing field study work with a scientist studying spiders in the Amazon rainforest. You come across a previously undiscovered species of spider and set up a video camera with a zoom lens to observe it closely without disturbing it. You see the female spider lay two eggs, kill an ant that tried to eat one of the eggs, and preserve the ant to feed the hatchlings the next day. She lays two more eggs as soon as the two offspring grow larger and leave. When your mentor asks for a monthly update, what exciting news do you have for her about this species? A) It exhibits unusual r-selected tendencies. B) It exhibits unusual K-selected tendencies. C) It exhibits unusual intelligent learning tendencies. D) It exhibits unusual zero population growth tendencies.

Q: Which of the following would be generally true of r-selected species? A) Most live until older age. B) All live very short life spans. C) R-selected species are larger organisms that produce few offspring. D) R-selected species are smaller organisms that produce many offspring.

Q: Which of the following items can be classified as a density independent factor in population growth? A) food supply B) disease C) temperature D) drinking water supply

Q: A biologist is studying the population dynamics of pocket gophers in a meadow in central Oregon. She noted that, when population numbers are high, death rates from disease and starvation increase. This is an example of: A) r-selected growth. B) the principle of intrinsic rate of growth. C) exponential growth. D) density dependent control.

Q: "Life is a lottery and it makes sense simply to buy many tickets" is a strategy for organisms that exhibit: A) K-selected growth. B) sigmoidal growth. C) density dependent growth. D) density independent growth.

Q: Most insects would be typical of which survivorship curve category? A) early-loss species B) constant-loss species C) late-loss species D) late-gain species E) early-gain species

Q: Humans would be typical of which survivorship curve category? A) early-loss species B) constant-loss species C) late-loss species D) late-gain species E) early-gain species

Q: Oak trees grow slowly and put a lot of resources into the trunk, bark, and roots. Seeds are relatively heavy. In the plant kingdom, oaks might be considered: A) density independent. B) r-selected. C) opportunistic. D) K-selected.

Q: Which of the following would be a characteristic of a K-selected species? A) Most K-selected species live until older age. B) All K-selected species live very long life spans. C) Individuals tend to die at all ages in the life span. D) Most die at relatively young ages.

Q: Mosquitoes have a short life span and produce a very large number of eggs. This is typical of a/an: A) K-selected species. B) equilibrium species. C) r-selected species. D) density dependent species.

Q: Which of the following species would be classified as an opportunistic species? A) humans B) houseflies C) chimpanzees D) kangaroos

Q: Which of the following is a density dependent limiting factor? A) weather B) rain C) frost D) food supply

Q: Which of the following organisms represent a K-selected species? A) whales B) houseflies C) grasshoppers D) salmon

Q: If a population's death rate is 5 percent and birth rate is 10 percent, its r value would be: A) 15 percent. B) 5 percent. C) 50 percent. D) essentially zero.

Q: Which of the following would be a valid, general pattern seen in generation time? A) Nearly all K-selected organisms have short generation times. B) Species with the fastest growth rates have the longest generation times. C) The larger the species is, the longer its generation time tends to be. D) All vertebrates have long generation times.

Q: The average amount of time that passes between the birth of a woman and the birth of her child is called: A) reproductive time. B) generation time. C) birth rate. D) population rate.

Q: A population's intrinsic rate of increase can be calculated by: A) subtracting r from K. B) multiplying r by K. C) multiplying r by the initial population size, N. D) subtracting birth rate from death rate.

Q: A negative rate of increase, or a negative r, means that: A) the population is shrinking. B) the population has a short generation time. C) death rates have decreased. D) there is zero population growth.

Q: K, in population growth equations, refers to: A) carrying capacity. B) the predation factor. C) environmental resistance. D) biotic potential.

Q: A population of rabbits introduced to an island grows rapidly for a few years, and then growth slows and stabilizes. The population becomes stable because: A) the intrinsic rate of increase has declined. B) environmental resistance declined. C) immigration was reduced. D) the carrying capacity has been reached.

Q: Which of the following would be an example of environmental resistance? A) food supply increasing along with a population B) bacteria populations producing more toxic waste as they grow C) slow gestation periods D) life span that increases with population size

Q: The maximum population density of a given species that a defined geographical area can sustain over time is known as the: A) community capacity. B) ecosystem capacity. C) maximum yield. D) carrying capacity.

Q: Which of the following is true of a population's intrinsic rate of increase? A) It is the rate at which a population would grow if there were no external limits to growth. B) It is the death rate minus the birth rate, or a measure of annual population change in a population near K. C) It is the rate at which populations grow in nature in the face of all environmental limits. D) It occurs when the birth rate equals the death rate.

Q: Which of the following is true of logistic growth? A) Logistic growth occurs when predators are very limited in population size. B) Logistic growth may start in a way that resembles exponential growth but slows and stabilizes. C) Logistic growth describes the growth of a population in an environment with an unlimited carrying capacity. D) Logistic growth is plotted as a J-shaped curve.

Q: Which of the following is true of exponential growth? A) Exponential growth occurs when there are many environmental limits to reproduction. B) Exponential growth resembles an S-shaped curve when plotted on a graph. C) Exponential growth is growth that continues accelerating with time. D) Exponential growth resembles a straight line when plotted on a graph.

Q: Generally speaking, which of the following would be the best description of ecology? A) study and preserve the environment B) study and conserve the environment C) study the environmental conditions that plants and animals depend on for survival D) study the interactions of living things with each other and their environments

Q: A community ecologist might study: A) the behavior of a species in its natural environment. B) all the members of a single species that live together in a single geographic area. C) the rates of increase or decrease in the population size of individual species in different environments. D) the interactions among species living in a single area.

Q: Studying the total amount of oxygen generated and released into the atmosphere by living things would be an example of studying ecology at which level? A) community B) population C) ecosystem D) biosphere

Q: Studying the variations in the number of carp in Lake Erie over a 20-year period would be an example of studying ecology at which level? A) community B) population C) ecosystem D) biosphere

Q: Studying the amount of carbon stored in the forest floor per hectare in a boreal forest in Canada after a fire would be an example of studying ecology at which level? A) biosphere B) ecosystem C) community D) population

Q: Refer to the figure below, and then answer the question that follows. Which item, A, B, C, D, or E, is a secondary spermatocyte?

Q: Refer to the figure below, and then answer the question that follows.Which item, A, B, C, D, or E, represents the structure that maintains the female reproductive tract during the early part of pregnancy?

Q: Evaluate this statement: By the end of the first trimester, most growth in a fetus is in size, not complexity.

Q: Propose reasons to explain why the female reproductive system evolved a menstrual cycle, but the male system does not adhere to any kind of true cycle.

Q: Given the loss of childbearing ability and negative health effects associated with menopause, there is cause to question why it exists given that evolution usually selects against most negative health effects and reduced fertility. Appraise and compare the two possible explanations covered in this section.

Q: Which is the only trimester to include both the embryo and fetal stages?

Q: Enzymes are carried in the ________ of a sperm.

Q: What is the long tube through which mature sperm are transported to the urethra during ejaculation?

Q: Primary and secondary ________ develop into spermatids.

Q: Implantation occurs in the ________ of the uterus.

Q: The release of an oocyte from an ovary is called ________.

Q: Match the following.A) makes female hormonesB) sperm storageC) sperm stem cellD) becomes the fetal portion of the placentaE) enzyme storageAcrosome

Q: Match the following.A) makes female hormonesB) sperm storageC) sperm stem cellD) becomes the fetal portion of the placentaE) enzyme storageCorpus luteum

Q: Match the following.A) makes female hormonesB) sperm storageC) sperm stem cellD) becomes the fetal portion of the placentaE) enzyme storageSpermatogonia

Q: Match the following.A) makes female hormonesB) sperm storageC) sperm stem cellD) becomes the fetal portion of the placentaE) enzyme storageTrophoblast

Q: Match the following.A) makes female hormonesB) sperm storageC) sperm stem cellD) becomes the fetal portion of the placentaE) enzyme storageEpididymis

Q: The normal position of the fetus at the start of labor is "upside down."

Q: The developing organism is referred to as a fetus during its first eight weeks.

Q: Human pregnancy lasts an average of about 38 weeks.

Q: Human embryos do not go through a morula stage of development as do most other animals.

Q: Sperm cells do not need a nucleus and expel it during development as a weight-saving tactic.

Q: It generally takes the enzymes from dozens of sperm for one sperm to gain access to the oocyte membrane.

Q: The male stem cells in sperm production are the spermatogonia.

Q: Sperm develop in the seminal vesicles.

Q: Sperm development requires temperatures somewhat cooler than found in the rest of the body.

Q: There is an epididymis adjacent to each testis.

Q: Sperm are fully mature when they reach the epididymis.

Q: A woman begins puberty with about 400,000 follicles.

Q: Menstruation refers to the later life cessation of the monthly ovarian cycle.

Q: Corpus luteum translates as "yellow body."

Q: An ovarian follicle is a developing oocyte and the follicular cells surrounding it.

Q: An egg implants in the uterus and awaits sperm for fertilization.

Q: Women produce oocytes from stem cells from puberty all throughout life.

Q: In humans, females contribute more resources to reproduction and development than males.