Exam 33: An Introduction to Invertebrates

How many of the following can be observed in the mesohyl of various undisturbed sponges at one time or another? 1)amoebocytes 2)spicules 3)spongin 4)zygotes 5)choanocytes

The water vascular system of echinoderms

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips. -The parapodia of polychaetes have a function most similar to that of

Which human profession is most analogous to the lifestyle of the sea slugs described in this scenario?

A farm pond, usually dry during winter, has plenty of water and aquatic pond life during the summer. One summer, Sarah returns to the family farm from college. Observing the pond, she is fascinated by some six-legged organisms that can crawl about on submerged surfaces or, when disturbed, seemingly "jet" through the water. Watching further, she is able to conclude that the "mystery organisms" are ambush predators, and their prey includes everything from insects to small fish and tadpoles. -From this description, one can conclude that the organisms that have caught Sarah's attention are

Percent of sea slug respiratory carbon demand provided by indwelling dinoflagellates. -According to the graph, during which season(s)of the year is the relationship between the sea slug and its dinoflagellates closest to being commensal?

The sharp, inch-long thorns of the crown-of-thorns sea star are its spines. These spines, unlike those of most other sea stars, contain a potent toxin. If it were discovered that crown-of-thorns sea stars do not make this toxin themselves, then the most likely alternative would be that this toxin is

A farm pond, usually dry during winter, has plenty of water and aquatic pond life during the summer. One summer, Sarah returns to the family farm from college. Observing the pond, she is fascinated by some six-legged organisms that can crawl about on submerged surfaces or, when disturbed, seemingly "jet" through the water. Watching further, she is able to conclude that the "mystery organisms" are ambush predators, and their prey includes everything from insects to small fish and tadpoles. -Sarah observed that the mystery pond organisms never come up to the pond's surface. If she catches one of these organisms and observes closely, perhaps dissecting the organism, she should find

A farm pond, usually dry during winter, has plenty of water and aquatic pond life during the summer. One summer, Sarah returns to the family farm from college. Observing the pond, she is fascinated by some six-legged organisms that can crawl about on submerged surfaces or, when disturbed, seemingly "jet" through the water. Watching further, she is able to conclude that the "mystery organisms" are ambush predators, and their prey includes everything from insects to small fish and tadpoles. -Sarah had learned that ancestral (Carboniferous era)dragonfly species were much larger than extant dragonfly species are, with wingspans of 70 cm. This struck her as odd, because she had also learned that one of the things that keeps insects small is their relatively inefficient respiratory system. Which two hypotheses might help account for the large size of ancestral dragonflies? 1)If the atmosphere during the Carboniferous era had featured a higher oxygen content than the modern atmosphere, then the tracheae might have been a sufficient means for oxygen delivery to the interior tissues. 2)If large size was a drawback, then the large dragonflies underwent extinction, which explains why all extant dragonflies are smaller. 3)If the ancestral dragonflies had possessed muscles that permitted effective ventilation of the tracheae, then the tracheae might have been a sufficient means for oxygen delivery to the interior tissues. 4)If ancestral dragonflies existed during greenhouse conditions, then they must have survived by decreasing their activity levels, such as no longer capturing prey in flight. Thus, for them, an ineffective respiratory system was sufficient.

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips. -The small, thin extensions of the skin on the aboral surfaces of sea stars have a function most similar to that of

Which of the following is a diploblastic phylum of aquatic predators?

Sponges are most accurately described as

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips. -The spines of sea stars have a function most similar to that of

Nematode worms and annelid worms share which of the following features?

-Which of the following factors, when used to label the horizontal axis of the previous graph, would account most directly for the shape of the plot?

If the teacher had wanted to demonstrate that some invertebrates possess a closed circulatory system, the teacher should have removed and dissected a

Nudibranchs, a type of predatory sea slug, can have various protuberances (i.e., extensions) on their dorsal surfaces. Rhinophores are paired structures, located close to the head, which bear many chemoreceptors. Dorsal plummules, usually located posteriorly, perform respiratory gas exchange. Cerata usually cover much of the dorsal surface and contain nematocysts at their tips. -The lateral flaps of planaria heads have a function most similar to that of

A land snail, a clam, and an octopus all share

Which mollusc clade includes members that undergo embryonic torsion?

The heartworms that can accumulate within the hearts of dogs and other mammals have a pseudocoelom, an alimentary canal, and an outer covering that is occasionally shed. To which phylum does the heartworm belong?