|
| 1 | Multicellular life has been a part of life on earth for approximately ______ years. |
 | A) | 50 million |
| B) | 100 million |
| C) | 550 million |
| D) | 1.5 billion |
|
| 2 | The first animals may have arisen from a large multinucleate cell that subsequently formed plasma membranes within the cell to produce a small multicellular organism. This idea is known as the ______ hypothesis. |
| A) | colonial |
| B) | syncytial |
| C) | membrane |
| D) | Precambrian |
|
| 3 | Which of the following is a fossil formation in British Columbia containing about 20 animal body forms that are not assigned to any modern animal phyla? |
| A) | Burgess Shale |
| B) | Ediacara formation |
| C) | Tommotian formation |
| D) | Gemmule formation |
|
| 4 | All of the following are characteristic of members of the phylum Porifera except one. Select the exception. |
| A) | asymmetrical |
| B) | three cell types |
| C) | central cavity, or a series of branching chambers, through which water circulates during filter feeding. |
| D) | diploblastic tissue organization |
|
| 5 | Which of the following cell types is involved with creating water currents during filter feeding of a sponge? |
| A) | pinacocytes |
| B) | choanocytes |
| C) | porocytes |
| D) | mesenchyme cells |
|
| 6 | Which of the following cell types is involved with secreting skeletal elements of a sponge? |
| A) | pinacocytes |
| B) | choanocytes |
| C) | porocytes |
| D) | ameboid/mesenchymal cells |
|
| 7 | Which of the following cell types is involved with regulating water movements through a sponge? |
| A) | pinacocytes |
| B) | choanocytes |
| C) | porocytes |
| D) | mesenchyme cells |
|
| 8 | In an ascon sponge, choanocytes |
| A) | line radial canals that branch off the spongocoel. |
| B) | line the spongocoel directly. |
| C) | are found in flagellated chambers. |
| D) | line incurrent canals. |
|
| 9 | In a sycon sponge, the body wall appears to be |
| A) | highly folded. |
| B) | thick and perforated by a highly branched canal system. |
| C) | unfolded and not perforated by a branched canal system. |
| D) | a single cell layer thick. |
|
| 10 | The most complex sponges have a body organization called |
| A) | sycon. |
| B) | leucon. |
| C) | ascon. |
| D) | mycon. |
|
| 11 | All of the following are characteristic of members of the phylum Cnidaria except one. Select the exception. |
| A) | radial or biradial symmetry |
| B) | nervous system in the form of a nerve net |
| C) | choanocytes used in defense, feeding, and attachment |
| D) | gelatinous mesoglea located between epidermal and gastrodermal tissue layers |
|
| 12 | In the life cycle of a member of the class Hydrozoa, for example Obelia, |
| A) | the polyp stage is always predominant. |
| B) | the medusa stage is always predominant. |
| C) | the medusa and polyp are both usually present. |
| D) | nematocysts are absent. |
|
| 13 | Members of the class Scyphozoa include |
| A) | anemones. |
| B) | corals. |
| C) | Hydra. |
| D) | jellyfish. |
|
| 14 | The largest and most prominent stage in the life cycle of most members of the class Scyphozoa is the |
| A) | medusa. |
| B) | planula. |
| C) | polyp |
| D) | ephyra. |
|
| 15 | The class of Cnidaria that includes anemones is |
| A) | Hydrozoa. |
| B) | Scyphozoa. |
| C) | Anthozoa. |
| D) | Calcarea. |
|
| 16 | Most of the history of multicellular life on earth has been one of extinction rather than the origin of new kinds of animal life. |
| A) | True |
| B) | False |
|
| 17 | Members of the class Scyphozoa have life histories in which the medusa stage is produced asexually from the strobila. |
| A) | True |
| B) | False |
|
| 18 | The coelom of cnidarians functions in digestion, the exchange of respiratory gases, and discharge of gametes. |
| A) | True |
| B) | False |
|
| 19 | Cells are never present in the mesoglea of cnidarians. |
| A) | True |
| B) | False |
|
| 20 | Cnidocytes produce nematocysts that are discharged on stimulation of a cnidocil. Cnidocytes are produced only in members of the phylum Cnidaria. |
| A) | True |
| B) | False |
|
| 21 | In many members of the class Hydrozoa, the gonozooid is a reproductive polyp that produces medusae by budding. |
| A) | True |
| B) | False |
|
| 22 | Some members of the class Cubozoa have nematocysts that are dangerous to humans. |
| A) | True |
| B) | False |
|
| 23 | Hydrozoan polyps have mesenteries that bear nematocysts, a mouth that leads to a pharynx, and a mesoglea containing ameboid mesenchyme cells. |
| A) | True |
| B) | False |
|
| 24 | Some members of the class Anthozoa are monoecious. In these animals, the male gametes often mature before the female gametes, thus preventing self-fertilization. This condition is called protandry. |
| A) | True |
| B) | False |
|
| 25 | Some anthozoans live in a mutualistic relationship with protists called zooxanthellae and are largely responsible for the formation of coral reefs. |
| A) | True |
| B) | False |