Exam 33: An Introduction to Invertebrates

In terms of food capture,which sponge cell is most similar to the cnidocyte of a cnidarian?

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.

Which of the following animal groups is entirely aquatic?

Which of the following characteristics is common to all sponges?

The sea slug Elysia chorotica has no nematocysts or dinoflagellates but,rather,has "naked" chloroplasts in its skin.The chloroplasts are all that remain of the seaweed (Vaucheria sp.)that Elysia feeds upon.The chloroplasts are transferred to the skin; consequently,this slug is green.It spends most of its time basking in shallow water on the surface of seaweeds.How should we expect its chloroplasts to benefit the Elysia sea slug? 1)provide Elysia with fixed CO₂ 2)provide Elysia with fixed N₂ 3)provide Elysia with protective colouration

Against which hard structure do the circular and longitudinal muscles of annelids work?

A natural predator of the crown-of-thorns sea star is a mollusc called the Giant Triton,Charonia tritonis.If the triton uses a radula to saw into the sea star,then to which clade should the triton belong?

How would a terrestrial centipede most likely benefit from the ability to close its spiracles? Closing spiracles would

Most cnidarians are known to produce toxins.In fact,it has been claimed that one particular species produces the most deadly of all toxins on the planet.What feature of this group most likely evolved simultaneously with the evolution of these toxins?

A stalked,sessile marine organism has several feathery feeding structures surrounding an opening through which food enters.The organism could potentially be a cnidarian,a lophophorate,a tube-dwelling worm,a crustacean,or an echinoderm.Which of the following traits,if found in this organism,would allow the greatest certainty of identification?

How many of the following are characteristics of arthropods? 1)protostome development 2)bilateral symmetry 3)a pseudocoelom 4)three embryonic germ layers 5)a closed circulatory system

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

Use the following information to answer the questions below. 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

The reason their exoskeletons cannot protect the corals from sea stars is that the sea star

The clownfish readily swims among the tentacles of the sea anemones; the parrotfish avoids them.One hypothesis for the clownfish's apparent immunity is that they slowly build a tolerance to the sea anemone's toxin.A second hypothesis is that a chemical in the mucus that coats the clownfish prevents the nematocysts from being triggered.Which of the following graphs supports the second,but not the first,of these hypotheses?

Cold water corals are prevalent in the Atlantic Ocean off the coast of Nova Scotia.These cold water corals

A student observes a wormlike organism crawling about on dead organic matter.Later,the organism sheds its outer covering.One possibility is that the organism is a larval insect (like a maggot).However,it might be a member of the phylum ________,and one way to distinguish between the two possibilities is by looking for ________.

Nudibranchs usually have two rhinophores.However,if they had a single rhinophore,it could still carry out the function of two rhinophores,and with similar effectiveness,if this single rhinophore

Which phylum is characterized by animals that have a segmented body?

Use the following information to answer the questions below. 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 antennae of insects have a function most similar to that of