CHAPTER 19 Test Your Knowledge
Driving Question 1
What are eukaryotic organisms, and what factors influence their diversity?
By answering the questions below and studying Infographics 19.1 and 19.3, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
How does the physical landscape diversity of Olympic National Park affect biodiversity in the park?
There are a variety of habitats in the park, including freshwater lakes and streams, marine environments at the ocean coastline, glacier-topped mountains, and temperate rain forest. A wide variety of organisms with different adaptations for these different habitats can live in the park.
What are the defining features of eukaryotes, members of the domain Eukarya?
Eukaryotes are defined by having cells with membrane-bound organelles, including a nucleus.
What do a fisher and a fir tree have in common?
They are both eukaryotic and live in Olympic National Park.
USE IT
How do you think the diversity of eukaryotic organisms in each of the following areas would compare to the diversity in Olympic National Park—would there be more or less? Explain the reasons for your answers.
a. Lake Michigan
b. the Sonoran Desert in Arizona
c. the prairies of Kansas
a: Lake Michigan would likely have less diversity, as it has less varied habitat than Olympic National Park. b: The Sonoran desert would likely have less diversity because of the extremely dry climate and high summer temperatures. Only some organisms have adaptations allowing them to survive in such conditions. c: The prairies of Kansas would likely have less diversity—the landscape is not very varied, and is dominated by grasslands.
If a fungicide were applied throughout Olympic National Park, how might it affect eukaryotes in the park? Explain your answer.
A fungicide would kill the fungi. As fungi play critical roles in decomposition, their absence would lead to a lack of decomposition and an accumulation of dead organic matter in the park. This would trap nutrients in the dead material, not allowing them to cycle and be available to other organisms in the park. The accumulation of dead organic matter would increase the amount of potential fuel for a wildfire, and would affect the amount of space and light available to other organisms.
Driving Question 2
How are plants defined, and what influences their diversity?
By answering the questions below and studying Infographic 19.3, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
Which group of plants was the first to live on land? Why do we find these plants only in particular environments (after all, if they were first, shouldn’t they have spread everywhere by now)?
The bryophytes were the first plants to live on land. As they do not have a vascular system to transport water throughout their bodies, they live in damp environments. They do not have adaptations that would enable them to live in other, drier environments.
A major difference between a fern and a moss is
a. the presence of seeds.
b. the presence of flowers.
c. the presence of cones.
d. the presence of a vascular system.
e. the ability to carry out photosynthesis.
d
USE IT
What is an advantage of having seeds? (Think about spreading to new locations and whether or not reproduction relies on water.)
Seeds contain plant embryos in a protective coating. Seeds enable plants to survive temporarily harsh conditions and because they spread relatively easily, can spread plants to new locations.
What type of seed plant is likely to rely on hungry animals to spread its seeds? Explain your answer.
An angiosperm: its seeds are enclosed in a fruit, which can be a tasty treat for a hungry animal.
How did the evolution of vascular systems in plants change the landscape?
Once vascular plants evolved in plants, plants were able to grow taller and live in a variety of habitats, not just in damp places. Plants are present in almost every landscape and are important in characterizing different habitats.
Driving Question 3
How are animals defined, and what influences their diversity?
By answering the questions below and studying Infographic 19.4, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
A sand dollar gets its name from its body shape–it resembles a large coin. What type of body symmetry does a sand dollar have?
a. bilateral
b. radial
c. none (sand dollars are amorphous)
d. hyphae
e. mycelium
b
What do a backbone and an exoskeleton have in common?
a. They are found in closely related groups of animals.
b. They are made of the same substance.
c. They both help provide support to an animal’s body.
d. They both require an animal to molt in order to be able to grow.
e. all of the above
c
428
You and a fisher are both mammals; as such, what are some characteristics you and the fisher have in common?
As mammals, both fishers and humans have backbones, mammary glands and body hair.
Which of the following statement(s) is/are true about both cockroaches and lobsters?
a. They are invertebrate insects with bilateral symmetry.
b. They are mollusks with an exoskeleton.
c. They are arthropods with segmented bodies and no symmetry.
d. They are arthropods with an exoskeleton.
e. They are mollusks with a segmented body.
d
USE IT
Many characteristics are used to classify animals. Why do we need to use so many different characteristics? Consider the following five animals: woodpecker, human, wasp, ant, and fisher; and the following three characteristics: ability to fly, two-legged, bearing feathers
a. Which of the five animals could be grouped by each characteristic?
b. Would this grouping reflect their real taxonomic relationship?
c. By what feature(s) would you put wasps and ants together in their own group? What about humans and fishers?
a: Ability to fly: the woodpecker and wasp, which can fly, would be grouped together, and the human, fisher, and ant would be grouped together as nonflying. Two-legged: humans and woodpeckers are two-legged, while the wasp, ant and fisher are not. Having feathers: only the woodpecker has feathers—the human, ant, fisher, and wasp do not have feathers. b: None of the groupings above reflects the true taxonomic relationships. c: Wasps and ants are both arthropods, and so have exoskeletons, segmented bodies and jointed appendages. Fishers and humans are both mammals, and so have mammary glands and fur-covered bodies.
Judging from their numbers, arthropods are a tremendously successful group. What traits do you think have enabled them to be so successful? Justify your answer with examples.
Arthropods have an exoskeleton that helps protect them from predators and helps prevent the organisms from drying out. Many arthropods produce venoms that help ward off predators. Many can fly, allowing them to escape predators and seek food over relatively long distances. Many have mouthparts that allow biting and sucking to obtain food. Some have complex social behavior that allows them to work as a group.
Driving Question 4
How are fungi defined, and what influences their diversity?
By answering the questions below and studying Infographic 19.5, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
Consider the “eating habits” of fungi.
a. Can fungi carry out photosynthesis?
b. Can fungi ingest their food?
c. How do fungi obtain their nutrients and energy?
a: Fungi are not photosynthetic; they are heterotrophs. b: They do not ingest their food. c: They obtain nutrients and energy by secreting digestive enzymes onto their food. The food is then digested into smaller subunits, which are then absorbed by the fungi.
Which of the following meals include fungi as food?
a. a bread and blue cheese platter with fruit
b. mushroom risotto
c. a and b
d. a fruit salad
e. yogurt
c
USE IT
A very early classification scheme placed the fungi together with the plants. Why do you think fungi were grouped with plants? What features distinguish them from plants?
While both plants and fungi are eukaryotes, they are members of distinct groups. Fungi were likely originally classified with the plants both because they grow in the soil and they don’t move (that is, they are immotile). Fungi are distinguished from the plants by having a cell wall made up of chitin instead of cellulose, and by being heterotrophs (they can’t carry out photosynthesis).
Driving Question 5
What are protists, and what influences their diversity?
By answering the questions below and studying Infographic 19.6, you should be able to generate an answer for the broader Driving Question above.
KNOW IT
What do all members of the informal group known as protists have in common?
a. nothing
b. They are all eukaryotic.
c. They all carry out photosynthesis.
d. They are all human parasites.
e. They are all decomposers.
b
USE IT
Why do scientists no longer consider protists a separate kingdom? How might scientists find new taxonomic “homes” for the protists? Do you think structural features (for example, chloroplasts) or genetic information will be more useful in their classification?
Protists are no longer considered a separate kingdom because the protists are not more similar to one another than to organisms in other groups. Some are photosynthetic and some are not, some are decomposers, some eat other organisms. Genetic information will be more useful than structural features in future classifications of protists.
Many protists have an organelle called the contractile vacuole that pumps out water that enters the cell by osmosis. Why is this a useful adaptation for a protist? What might happen to a protist if its contractile vacuole stopped working? (Think about where many protists live, and what happens to bacteria whose cell walls are disrupted by antibiotics.)
In a freshwater environment, water tends to enter the cells of protists, increasing the internal pressure. A contractile vacuole enables protists to pump out some of that excess water. If the contractile vacuole stopped working, the accumulated water might generate enough pressure to burst the cell.
MINI CASE
Reintroducing species to their native habitats is sometimes controversial. One reintroduction effort in particular that has caused quite a stir is the reintroduction of the Mexican gray wolf (Canis lupus baileyi) into New Mexico and Arizona. You can read about this project at http://www.fws.gov/southwest/es/mexicanwolf/
a. Why might it be important to reintroduce species into their native habitats? Answer first in general terms, then specifically for the Mexican gray wolf.
b. What factors could impede the success of such reintroductions? Again, answer in general terms first, then specifically for the Mexican gray wolf.
a: Species are part of a community in their native habitats, and thus help maintain a healthy community. Reintroducing endangered species into their native habitats, gives them the greatest chance of successfully surviving and reproducing, thus restoring their numbers. The Mexican gray wolf is an endangered species, and reintroducing it into its native habitat may help it avoid extinction. The Mexican gray wolf preys on a variety of other organisms, so its presence helps to control the populations of those species, avoiding possible negative impacts (e.g., on plant species) of large herbivore populations. Mexican gray wolves are scavengers, contributing to cleaning of carcasses. b: Factors that could impede the successful reintroduction include insufficient intact, unaltered habitat and resistance from local human communities. In the case of the Mexican Gray Wolf, humans in the area of introduction are concerned that the wolves will prey on livestock or humans, and may also prey on animals that humans hunt, reducing their numbers.
429
INTERPRETING DATA
The otter was officially declared extinct in the Netherlands in 1988. A reintroduction program was started in 2002. The reintroduced otters were either captured in Eastern Europe, or bred in captivity in countries including Sweden and Russia. Between 2002 and 2008, a total of 31 otters were released into a specific area in the Netherlands.
DNA from otter “spraint” (fecal material) was used to identify individual otters, and their offspring. The DNA spraint data are summarized in the table below.
a. Graph these data.
b. What is the total otter population in the Netherlands by the seventh year of the project?
c. What appears to be the major contributor to the otter population: introductions of new otters, or breeding of otters in the Netherlands?
a. What does the genetic diversity analysis suggest about inbreeding?
b. From all the data presented, is the otter reintroduction successful?
c. What recommendations would you make to ensure the long-term survival of otters in the Netherlands?
Part 1
a: Graph is not provided in answer key.
b: The total population is at least 51 (on the basis of spraints). c: By the time of the end of the study, the breeding of otters is making the largest contribution. Only 31 otters were introduced, but the population is 51, with 45 of those having been born in the Netherlands.
Part 2
a: As the average number of alleles per gene is decreasing; that suggests there may be some inbreeding. b: It appears that the reintroduction has been successful. Otters are breeding and their population size is increasing. c: To ensure long-term success, it may be worth considering introducing some otters from another area, to introduce some new alleles. It is also worth considering how to minimize car–otter interactions, to reduce the number of otters killed in accidents.
BRING IT HOME
Many species reintroductions are being carried out across the United States. Do some research to learn about at least one such effort. For the species you research, address the following questions:
a. What caused it to be lost from its native habitat?
b. Is its reintroduction important?
c. Are there are controversies about its reintroduction?
d. What made you interested in this particular species and its reintroduction? Is it an “attractive” species? Is it being reintroduced near where you live?
Answers will vary.