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Inquiry Questions

None for this chapter.

Self Test

1). Which of the following is a characteristic of chordates but is not found in other animals?
    a). a notochord
    b). jointed appendages
    c). an exoskeleton
    d). all of these
Answer: a

2). In which animal(s) does the notochord persist in the adult?
    a). tunicates
    b). lampreys
    c). lancelets
    d). all of these
Answer: c

3). The very first vertebrates were
    a). cartilaginous fish.
    b). fishes with jaws.
    c). amphibians.
    d). jawless fish.
Answer: d

4). Which of the following is not a characteristic of fishes?
    a). gills
    b). lungs
    c). single-loop blood circulation
    d). nutritional deficiencies
Answer: b

5). What adaptation of bony fish allows them to detect and orient itself in the upstream direction?
    a). the swim bladder
    b). lobed fins
    c). the operculum
    d). the lateral line system
Answer: d

6). In order for amphibians to be successful on land, they had to develop which of the following?
    a). a more efficient swim bladder
    b). cutaneous respiration and lungs
    c). more efficient gills
    d). shelled eggs
Answer: b

7). Amniotic eggs evolved as a means to
    a). protect the embryo while the parent sits on the egg.
    b). protect the embryo from predators.
    c). allow the parent to gather food, rather than sitting on the nest.
    d). prevent the embryo from drying out.
Answer: d

8). A group of early reptiles that may have been warm-blooded was the
    a). pleycosaurs.
    b). therapsids.
    c). thecodonts.
    d). all of these.
Answer: b

9). Archaeopteryx is believed to be the transition fossil between dinosaurs and birds because, like a bird, Archaeopteryx had feathers and
    a). a tail similar to modern birds.
    b). scales.
    c). a toothless, elongated mouth like a beak.
    d). a fused collarbone indicating flying ability.
Answer: d

10). Mammals that have live births incubate newborns in a pouch through the completion of development are:
    a). monotremes.
    b). marsupials.
    c). duck-billed platypuses.
    d). placental mammals.
Answer: b

Test Your Visual Understanding

1). Based on this figure, predict the type of consumer is a carnivore, herbivore, or omnivore.
    a). dog
    b). deer
    c). beaver
    d). elephant
    e). human
    a). carnivore
    b). herbivore
    c). herbivore
    d). herbivore
    e). omnivore

Apply Your Knowledge

1). Homeothermic animals use 98% of cellular energy in metabolism and "store" 2% for growth. Poikilotherms have lower metabolisms and so are able to store 44% of cellular energy for growth. For homeotherms, 77.5% of chemical energy is converted into cellular energy with an efficiency of 77.5%. By comparison, poikilotherm efficiency is 41.9%. How much food must be consumed by each type of animal to gain one gram of weight?
Answer: For homeotherms the food that needs to be consumed is the unknown—x. This quantity of food must be multiplied by the efficiency (77.5%) and the percent of energy "stored" for growth (2%) to produce one gram of weight such that:
(0.775)(0.02)x = 1 gram
(0.0155)x = 1 gram
(0.0155)x / (0.0155) = 1 / (0.0155)
x = 64.5 grams
For poikilotherms:
(0.419)(0.44)x = 1 gram
(0.184)x = 1 gram
(0.184)x / (0.184) = 1 / (0.184)
x = 5.43 grams

2). What characteristics allowed vertebrates to attain great sizes?
Answer: Several of the characteristics that make a vertebrate a vertebrate also contributed to its increased size.
By forming a vertebral column and endoskeleton, the vertebrate was able to grow larger because internal bones could support additional weight and allowed for improved locomotion of a larger animal.
The formation of internal organs allowed compartmentalization of bodily functions (i.e., digestion, respiration, circulation, etc.), which increased efficiency in a larger animal.
The localization of neural functions in a "head" centralized the nervous system and allowed it to function more efficiently in a larger animal.

3). What limits the ability of amphibians to occupy the full range of terrestrial habitats and allows other terrestrial vertebrates to occupy them successfully?
Answer: Amphibians are limited from expanding into all terrestrial habitats by their reliance on water, both to keep their bodies moist for cutaneous respiration and to use for reproduction. If water isn't readily available in a habitat, amphibians will not be able to survive. Reptiles and mammals are able to dominate in habitats where amphibians would die due to dehydration but even reptiles are limited to habitats that have moderate temperatures. Reptiles cannot live in habitats that are too cold and need to modify their behavior to survive in extremely hot climates (such as hiding during the day and only coming out at night when it's cooler).

4). List some of the advantages that the early birds, in which flight was not nearly as efficient as it is in most of their modern descendants, might have had as a result of the presence of feathers.
Answer: Feathers would have provided an advantage in insulation. Whether the early birds were endothermic or ectothermic, the ability to trap in heat would have been an advantage in cooler climates. Feathers could have also provided a protection from injury or infection. The feathers could have provided a cushion or layer that predator's teeth or claws would have to penetrate or barrier that pathogens would have to penetrate in order to infect the animal.

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