Questions and Answers of Biology Concepts Investigations

An endocrine disruptor is a molecule that either mimics or blocks the activity of a hormone. Propose a way to test the hypothesis that microwaving foods in plastic containers releases endocrine
Write a paragraph describing the events that occur from the time an endocrine gland releases a steroid hormone to the time the hormone exerts its effects on a target cell.
Sketch the mechanisms of water-soluble and lipid-soluble hormone function.
Give two examples of hormones counteracting the effects of one another.
Alcohol and caffeine inhibit the effects of antidiuretic hormone. Explain why drinking beer or coffee increases the frequency of urination. If your urine appears dilute (is light yellow) after
Some professional baseball players use human growth hormone (a banned substance) to aid in fast recovery after difficult workouts. How would GH help speed a player’s recovery? Is GH use the same as
Which hormone(s) match each of the following descriptions?a. Produced by a woman who is breast feedingb. Causes fatigue if too little is presentc. Causes a decrease in blood glucose level
Why can a stressful lifestyle lead to heart attacks? Which hormone is released in response to long-term stress?
How might insulin-producing stem cells transplanted to the pancreas help people with type 1 diabetes? Would the same treatment help people with type 2 diabetes?
In healthy adults, the concentration of glucose in blood is approximately 80 to 110 milligrams per deciliter (mg/dl). After a carbohydrate-rich meal, however, the concentration may spike to 140
Identify the target cells and effects of estrogen, progesterone, and testosterone.
Refer to figure 40.27 and the chapter content to answer the following questions.1. Review the Survey the Landscape figure in the chapter introduction. Add the terms population, community, or
Refer back to section 12.7, which describes the bottleneck effect. With this information in mind, why might recovery be difficult for species, such as cheetahs, that are nearly extinct?
Phytoremediation is the use of plants to treat environmental problems. Search the Internet for applications of phytoremediation. What are the benefits of phytoremediation? If you were trying to
In the southeastern United States, several species of freshwater mussels are extinct or threatened because of habitat destruction. In the past, they were also harvested for the button trade. How
One way to combat invasive species is to kill the invaders. In Hawaii, officials shoot feral cats, goats, and pigs. In Australia, the government fought zebra mussels by adding chlorine and copper to
People often move plants from one part of the world to another. Sometimes, an introduced plant species can become invasive, taking over native plant populations. The U.S. Department of Agriculture
DNA evidence recently confirmed the existence of a “pizzly bear,” the offspring of a polar bear and a grizzly bear. Scientists hypothesize that some polar bears are staying on mainland because of
Explain how habitat destruction, the increasing human population, and pollution contribute to climate change.
In what ways is the greenhouse effect both beneficial and detrimental?
Use the Internet to research ways to make homes more energy efficient. How does reducing your monthly energy bill relate to the conservation of biodiversity?
Suppose you throw a small piece of plastic in the garbage. List three places where the plastic might be found months later.
What are examples of pollutants in air and in water? Which of these pollutants eventually reach land?
Nanoparticles are tiny bits of metal that are used in sunscreens, as a wastewater treatment, and for many other purposes. Recent evidence suggests that nanoparticles are toxic to phytoplankton, the
When trees are removed from an area, patches or strips of untouched trees often intersperse the deforested land. How is the abiotic environment on the edge of these strips or patches different than
How does human population growth contribute to each of the main factors causing species extinctions?
List the main threats to biodiversity worldwide.
Refer to figure 39.28 and the chapter content to answer the following questions.1. Review the Survey the Landscape figure in the chapter introduction. What major factors determine how scientists
Hundreds of millions of years ago, Earth’s landmasses were joined into one supercontinent, Pangaea. If Pangaea had never broken up, do you think there would be more biodiversity, less biodiversity,
The biomes described in this chapter do not include those that humans create, such as cities, villages, croplands, rangelands, and tree farms. How are these biomes similar to and different from the
In a eutrophic lake, photosynthesis by phytoplankton does not maintain deep-water oxygen levels. Why not?
Make a concept map depicting the relationships among the zones of the ocean. What is the main energy source in each zone?
Use the clues provided to determine which biome houses each of the following four fish. Yellowfin tuna swim in deep salt water; young sea bass occupy areas where fresh and salt water mix; brook trout
Nuisance aquatic plants such as hydrilla can disrupt the ecology of the littoral zone of a lake. Two of the most common ways to control nuisance aquatic plants are herbicides (chemicals that kill
Find where you live on the map in figure 39.7. In which major terrestrial biome is your home? Then, use the Internet to learn more about the ecosystem(s) near your home. In what ways do your
Polar bears live on the ice cap near the North Pole. Their numbers are dwindling, apparently because of both pollution and global climate change. List some specific ways that the melting of the
Why might it be unlikely for a rain forest plant in central Africa to have descendants that colonize the nearby savanna?
List adaptations of desert and polar ice animals to the climate of their respective biomes.
Explain why fire-adapted plants are common in Mediterranean shrublands. Why might fire-adapted plants be much less common in (or absent from) rain forests?
Tropical rain forests have nutrient-poor soils, and people who clear the forests for farming often abandon the land after a few years. However, the same soil previously supported diverse, abundant
Explain why sunlight is most intense at the equator.
How does the fact that Earth is a sphere tilted on its axis influence the distribution of life?
Refer to figure 38.28 and the chapter content to answer the following questions.1. Review the definitions of ecology, populations, communities, and ecosystems using the Survey the Landscape figure in
Suppose a friend says, “I hate germs! I wish we could kill all bacteria!” What would happen if your friend didn’t have bacteria in her body? What would happen to nutrient cycles without
Imagine that you could follow a single water molecule, carbon atom, nitrogen atom, and phosphorus atom from one animal into two abiotic reservoirs. Which atom or molecule is most likely to remain
Officials in the northeastern United States are proposing to serve dogfish a type of shark—in schools, prisons, and homeless shelters. The fish are cheap and abundant, and their populations
Mountain yellow-legged frogs live in the Sierra Nevada mountains. Their tadpoles mainly eat algae. One predator of adult frogs is a garter snake, which is eaten by bullfrogs. Recently, a chytrid
In a eutrophic lake, algae are abundant and dissolved oxygen levels are low. Predict how the pyramid of energy might appear for an ecosystem under these conditions.
Australian researchers removed a parasitic plant called mistletoe from a forest and observed the consequences. During the 3-year experiment, over 30% of the insect and bird species disappeared from
Search the Internet for “ecosystem services.” What does the term mean? List some examples of ecosystem services and reflect on what services might be most important to you.
Imagine that you could build a covered enclosure around a small ecosystem, blocking out all light and preventing gas exchange with the environment. How would the total amount of organic material,
Suppose a plot of forest is cleared of trees in anticipation of a new shopping mall. However, after the bulldozers are gone, the company runs out of money, and the land sits undisturbed for many
In an example of mimicry, a harmless jumping spider physically resembles an aggressive species of ant. Explain why this type of mimicry can exist only if the spiders are less abundant than the ants.
Researcher G. F. Gause tested how two species of paramecia (one-celled protists) responded to food availability. When grown in separate dishes, each population’s size was proportional to the amount
How does a community differ from an ecosystem?
Refer to figure 37.21 and the chapter content to answer the following questions.1. Review the Survey the Landscape figure in the chapter introduction, and then add ecosystems, nonliving environment,
What is your ecological footprint? To find out, search for the Personal Footprint Calculator on the Global Footprint Network website (or find a similar calculator on the Internet). What can you do to
A species with an opportunistic life history occupies a habitat where conditions fluctuate in 2-year cycles—that is, years with optimal conditions for population growth alternate with suboptimal
Distinguish between opportunistic and equilibrium life histories, and give an example of an organism with each type of life history.
Some animal behaviors seem at odds with survival and reproduction. For example, when food is scarce, a female scorpion may eat her own offspring. In addition, section 35.7 describes a male spider
Domesticated animals, such as house cats, may disturb ecosystems. Are outdoor cats a density-independent or density-dependent factor limiting the populations of birds? Explain your answer. Then,
Use the Internet to find a species that is growing out of control and a species that is endangered. Compare their birth rates, death rates, and other factors that are leading to the differences in
Define the following terms: per capita rate of increase, environmental resistance, and carrying capacity.
Suppose that in a population with an equilibrium life history, 60% of individuals are younger than reproductive age. Is the population likely to grow, remain stable, or decline? Why? Why might this
Refer to the logistic model of population growth shown in figure 37.8. What would be the growth rate (G) of the population if the population size (N) equaled the carrying capacity (K)? Explain your
Calculate the anticipated size of the rotifer population in figure 37.6 after 21 days. Explain your answer.Figure 37.6 Time Total Population at End of Day Day 20: G= 0.22/day x 4390 individuals = 966
Why might an ecologist be interested in studying population dynamics?
Describe the difference between population density and distribution. Why aren’t organisms always distributed evenly throughout their habitat?
Chapter 39 describes biomes, the major types of ecosystems. Pick a biome and discuss a community that might be found in that biome. What populations may be included in the community you selected?
List some of the ways you have interacted with your surroundings today. Categorize each item on your list as a population-, community-, or ecosystem-level interaction.
Refer to figure 36.28 and the chapter content to answer the following questions.1. Review the Survey the Landscape in the chapter introduction. Then, classify each of the nine behaviors listed in the
In the 1930s, the population geneticist J. B. S. Haldane famously said, “I would lay down my life for two brothers or eight cousins.” What was he talking about?
Suppose you read a story in a popular science magazine about social rodents that kill themselves and their offspring if the group becomes overcrowded. Why might a biologist be skeptical of these
Prey animals may use distraction displays when a predator is nearby. What selective pressures do these prey animals exert on predators? Explain why distraction displays may become more convincing
European cuckoos and American cowbirds are “brood parasites” that lay their eggs in the nests of other birds. The chicks are generally raised by “adoptive parents” whose own chicks receive
For multiple decades, scientists in Russia have selectively bred one group of foxes for aggression and bred a second group for friendliness toward humans. The offspring of aggressive foxes tend to be
Niko Tinbergen investigated how female digger wasps find their nests. After a wasp emerged, Tinbergen moved the pine cones surrounding the nest to a nearby location. Upon its return, the wasp flew to
Explain how biologists identify genes controlling behavior in a fruit fly. Why might it be difficult to identify similar genes in humans?
What do nonthreatening odors, repetitive sounds, and constant touch have in common?
In what ways is a taxis similar to and different from a tropism in a plant? Give an example of a taxis and a tropism.
Classify each of the following descriptions as either a proximate or an ultimate cause of behavior. For all proximate causes, speculate about a possible ultimate cause of the behavior.a. A surge of
Refer to figure 35.27 and the chapter content to answer the following questions.1. Review the Survey the Landscape figure in the chapter introduction and the Pull It Together concept map. Explain why
What kinds of studies and information would be necessary to determine whether exposure to a potential teratogen can cause birth defects a year later? How would such an analysis differ if it were a
What is the significance of the critical period in determining the type and severity of a birth defect?
Use the Internet to research the rate of cesarean sections (surgical removal of the baby) in the United States. Why might the incidence be so high?
Most physicians clamp and cut the umbilical cord immediately after birth, separating the baby from the nutrients and respiratory gases it receives from the placenta; other physicians wait to cut the
During labor, a baby may remain in the birth canal for hours. How does the baby not suffocate during this time?
Consult a website that describes and illustrates fetal development. What technology do you think would be necessary to enable a fetus born in the fourth month to survive in a laboratory setting?
Provide a general explanation for why men have nipples. Figure 35.17 may help.Figure 35.17 Week 6 Undifferentiated stage Glans Genital tubercle Urogenital folds Labioscrotal folds Urogenital fold
What is the source of nutrients for a developing preembryo? For an embryo? For a fetus?
For each of the following pairs of phrases, indicate if the first is greater than the second, if the second is greater than the first, or if the two are equal.a. The number of cells in a morula; the
After ovulation, LH transforms the ruptured follicle into the corpus luteum. As LH levels decline, the corpus luteum degenerates. However, if fertilization occurs, the preembryo starts producing a
A zygote is a single cell whose weight is immeasurably small, yet after countless cell divisions it develops into a newborn weighing approximately 3.5 kilograms. While in the uterus, the developing
What would happen if two sperm fertilized the same egg cell? If two sperm fertilized two egg cells?
Use the Internet to learn more about sexually transmitted diseases. Choose one to study in detail. What type of infectious agent causes the disease? What are the symptoms and long-term consequences
Write a paragraph describing the path of sperm to egg, starting with sperm in the epididymis. Hint: See figure 35.25.Figure 35.25 Path of sperm Path of egg Male Female
Is each of the following cell types haploid or diploid? How does each cell type relate to the others?a. An oogoniumb. A primary spermatocytec. A spermatidd. A secondary oocytee. A polar body derived
Point mutations usually occur during interphase of mitosis, but most chromosomal abnormalities arise during meiosis. Given the differences between gamete production in males and females, why is it
In many species, a female may mate with multiple males, increasing her chance of conception. Speculate about how this behavior may select for males with faster sperm or more numerous sperm per
How are the timetables different for oogenesis and spermatogenesis in humans?

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