10.E: Diversity of Eukaryotes (Exercises)
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10.1: Protists
Multiple Choice
Protists with the capabilities to absorb nutrients from dead organisms are called_____________.
A. photoautotrophs
B. autotrophs
C. saprobes
D. heterotrophs
- Answer
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C is the most specific answer (D is also correct, but is a more general answer)
Free Response
How does killing Anopheles mosquitoes affect the Plasmodium protists?
- Answer
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Plasmodium parasites infect humans and cause malaria. However, they must complete part of their life cycle within Anopheles mosquitoes, and they can only be transmitted to humans via the bite wound of a mosquito. If the mosquito population were decreased, then fewer Plasmodium would be able to develop and be transmitted to humans, thereby reducing the incidence of human infections with this parasite.
Without treatment, why does African sleeping sickness invariably lead to death?
- Answer
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The trypanosomes that cause this disease are capable of expressing a glycoprotein coat with a different molecular structure with each generation. Because the immune system must respond to specific antigens to raise a meaningful defense, the changing nature of trypanosome antigens prevents the immune system from ever clearing this infection. Massive trypanosome infection eventually leads to host organ failure and death.
10.2: Fungi
Multiple Choice
Which polysaccharide is usually found in the cell walls of fungi?
A. starch
B. glycogen
C. chitin
D. cellulose
- Answer
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C
What term describes the close association of a fungus with the root of a tree?
A. a rhizoid
B. a lichen
C. a mycorrhiza
D. an endophyte
- Answer
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C
Free Response
Why can superficial mycoses in humans lead to bacterial infections?
- Answer
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Dermatophytes that colonize skin break down the keratinized layer of dead cells that protects tissues from bacterial invasion. Once the integrity of the skin is breached, bacteria can enter the deeper layers of tissues and cause infections.
10.3A: The Plant Kingdom
Multiple Choice
The land plants are probably descendants of which of these groups?
A. green algae
B. red algae
C. brown algae
D. angiosperms
- Answer
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A
The event that leads from the haploid stage to the diploid stage in alternation of generations is ________.
A. meiosis
B. mitosis
C. fertilization
D. germination
- Answer
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C
Moss is an example of which type of plant?
A. haplontic plant (life cycle in which the haploid stage is the dominant stage of an "alternation of generations" life cycle where haploid and diploid stages alternate)
B. vascular plant
C. diplontic plant (life cycle in which the diploid stage is the dominant stage of an "alternation of generations" life cycle where haploid and diploid stages alternate)
D. seed plant
- Answer
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A
Free Response
What adaptations do plants have that allow them to survive on land?
- Answer
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The sporangium of plants protects the spores from drying out. Apical meristems ensure that a plant is able to grow in the two directions required to acquire water and nutrients: up toward sunlight and down into the soil. The multicellular embryo is an important adaptation that improves survival of the developing plant in dry environments. The development of molecules that gave plants structural strength allowed them to grow higher on land and obtain more sunlight. A waxy cuticle prevents water loss from aerial surfaces.
10.3B: Seedless Plants
Multiple Choice
Why do mosses grow well in the Arctic tundra?
A. They grow better at cold temperatures.
B. They do not require moisture.
C. They do not have true roots and can grow on hard surfaces.
D. There are no herbivores in the tundra.
- Answer
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C
Which is the most diverse group of seedless vascular plants?
A. the liverworts
B. the horsetails
C. the club mosses
D. the ferns
- Answer
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D
Which group are vascular plants?
A. liverworts
B. mosses
C. hornworts
D. ferns
- Answer
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D
Free Response
How did the development of a vascular system contribute to the increase in size of plants?
- Answer
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It became possible to transport water and nutrients through the plant and not be limited by rates of diffusion. Vascularization allowed the development of leaves, which increased efficiency of photosynthesis and provided more energy for plant growth.
10.3C: Seed Plants: Gymnosperms
Multiple Choice
Which of the following traits characterizes gymnosperms?
A. The plants carry exposed seeds on modified leaves.
B. Reproductive structures are located in a flower.
C. After fertilization, the ovary thickens and forms a fruit.
D. The gametophyte is longest phase of the life cycle.
- Answer
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A
What adaptation do seed plants have in addition to the seed that is not found in seedless plants?
A. gametophytes
B. vascular tissue
C. pollen
D. chlorophyll
- Answer
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C
Free Response
What are the most abundant of the four modern-day groups of gymnosperms?
- Answer
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Coniferophyta (The four modern-day groups of gymnosperms are Coniferophyta, Cycadophyta, Gingkophyta, and Gnetophyta.)
10.3D: Seed Plants: Angiosperms
Multiple Choice
Pollen grains develop in which structure?
A. the anther
B. the stigma
C. the filament
D. the carpel
- Answer
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A
Corn develops from a seedling with a single cotyledon, displays parallel veins on its leaves, and produces monosulcate pollen. It is most likely:
A. a gymnosperm
B. a monocot
C. a eudicot
D. a basal angiosperm
- Answer
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B
Free Response
Cycads are considered endangered species and their trade is severely restricted. Customs officials stop suspected smugglers, who claim that the plants in their possession are palm trees and not cycads. How would a botanist distinguish between the two types of plants?
- Answer
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The resemblance between cycads and palm trees is only superficial. Cycads are gymnosperms and do not bear flowers or fruit. Unlike palms, cycads produce cones; large, female cones that produce naked seeds, and smaller male cones on separate plants.
What are the two structures that allow angiosperms to be the dominant form of plant life in most terrestrial ecosystems?
- Answer
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Angiosperms are successful because of flowers and fruit. These structures protect reproduction from variability in the environment.
10.4A: Features of the Animal Kingdom
Review Questions
Which of the following is not a feature common to most animals?
A. development into a fixed body plan
B. asexual reproduction
C. specialized tissues
D. heterotrophic nutrient sourcing
- Answer
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B
Free Response
How are specialized tissues important for animal function and complexity?
- Answer
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Specialized tissues allow more efficient functioning because differentiated tissue types can perform unique functions and work together in tandem to allow the animal to perform more functions. For example, specialized muscle tissue allows directed and efficient movement, and specialized nervous tissue allows for multiple sensory modalities as well as the ability to respond to various sensory information; these functions are not necessarily available to other non-animal organisms.
Using the following terms, explain what classifications and groups humans fall into, from the most general to the most specific: symmetry, germ layers, coelom, embryological development.
- Answer
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Humans have body plans that are bilaterally symmetrical and are characterized by the development of three germ layers, making them triploblasts. Humans have true coeloms, and are thus eucoelomates. Humans are deuterostomes.
10.4B: Sponges and Cnidarians
Review Questions
Cnidocytes are found in _____.
A. phylum Porifera
B. phylum Nemertea
C. phylum Nematoda
D. phylum Cnidaria
- Answer
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D
Free Response
Describe the feeding mechanism of sponges and identify how it is different from other animals.
- Answer
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The sponges draw water carrying food particles into the spongocoel using the beating of flagella in the choanocytes. The food particles are caught by the collar of the choanocyte and brought into the cell by phagocytosis. Digestion of the food particle takes place inside the cell. The difference between this and the mechanisms of other animals is that digestion takes place within cells rather than outside of cells. It means that the organism can feed only on particles smaller than the cells themselves.
Compare the structural differences between Porifera and Cnidaria.
- Answer
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Poriferans do not possess true tissues, whereas cnidarians do have tissues. Because of this difference, poriferans do not have a nerve net or muscle cells for locomotion, which cnidarians have.
10.4C: Flatworms, Nematodes, and Arthropods
Review Questions
Free Response
Speculate as to what advantage(s) a complete digestive system has over an incomplete digestive system?
- Answer
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In a complete digestive system, food material is not mixed with waste material, so the digestion and uptake of nutrients can be more efficient. In addition, the complete digestive system allows for an orderly progression of digestion of food matter and the specialization of different zones of the digestive tract.
Describe a potential advantage and disadvantage of the cuticle of ecdysozoans.
- Answer
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An advantage is that it is a tough covering that is protective against adverse environments, and predators and parasites. A disadvantage is that it must be shed and regrown for the animal to grow, which requires energy and makes the animal vulnerable during this process.
10.4D: Mollusks and Annelids
Review Questions
Free Response
Describe the morphology and anatomy of mollusks.
- Answer
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Mollusks have a large muscular foot that may be modified in various ways, such as into tentacles, but it functions in locomotion. They have a mantle, a structure of tissue that covers and encloses the dorsal portion of the animal and secretes the shell when it is present. The mantle encloses the mantle cavity, which houses the gills (when present), excretory pores, anus, and gonadopores. The coelom of mollusks is restricted to the region around the systemic heart. The main body cavity is a hemocoel. Many mollusks have a radula near the mouth that is used for scraping food.
10.4E: Echinoderms and Chordates
Review Questions
Echinoderms in their larval state have _____.
A. triangular symmetry
B. radial symmetry
C. hexagonal symmetry
D. bilateral symmetry
- Answer
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D
The circulatory fluid in echinoderms is _____.
A. blood
B. mesohyl
C. water
D. saline
- Answer
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C
Which of the following is not a member of the phylum Chordata?
A. Cephalochordata
B. Echinodermata
C. Urochordata
D. Vertebrata
- Answer
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B
Free Response
Sessile adult tunicates lose the notochord; what does this suggest about one function of this structure?
- Answer
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It suggests that the notochord is important for support during locomotion of an organism.
During embryonic development, what features do we share with tunicates or lancelets?
- Answer
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During embryonic development, we also have a notochord, a dorsal hollow nerve tube, pharyngeal slits, and a post-anal tail.
10.4F: Vertebrates
Review Questions
Members of Chondrichthyes differ from members of Osteichthyes by having a ________.
A. jaw
B. bony skeleton
C. cartilaginous skeleton
D. two sets of paired fins
- Answer
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C
Sudoriferous glands produce ________.
A. sweat
B. lipids
C. sebum
D. milk
- Answer
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A
Free Response
What can be inferred about the evolution of the cranium and the vertebral column from examining hagfishes and lampreys?
- Answer
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Comparison of hagfishes with lampreys shows that the cranium evolved first in early vertebrates, as it is seen in hagfishes, which evolved earlier than lampreys. This was followed by evolution of the vertebral column, a primitive form of which is seen in lampreys and not in hagfishes.
Explain why frogs are restricted to a moist environment.
- Answer
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A moist environment is required as frog eggs lack a shell and dehydrate quickly in dry environments.
Describe three adaptations that allow for flight in birds.
- Answer
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Birds have feathers that streamline the bird body and assist in flight. They also have pneumatic bones that are hollow rather than tissue-filled. Birds are endothermic, which allows for a higher metabolism demanded by flight.