Annelida Can you think of some of the advantages of having a body cavity? (p. 45) Advantages of having a body cavity include: creating a space in which organ
systems can form and enlarge, the fluid filling the space can be used to transport
materials, and the coelom allows the gut to move independently of the body wall.
What are some of the different functions of coelomic fluid? (p. 46) In animals that don't have a circulatory system, coelomic fluid can be used
to transport oxygen and carry metabolic wastes to excretory structures. Coelomic
fluid may function as a hydraulic medium in animals with hydrostatic skeletons,
be involved in heat transfer, and help protect internal organs from damage by
being a shock absorber for organs floating in the fluid-filled environment.
Substrate feeding is one of a number of different feeding strategies. What
are some of the others? (p. 46) There are a number of ways that feeding strategies can be defined. One is based
on what an animal feeds on: herbivores feed on plants; carnivores on other animals;
and omnivores consume any combination of plants, animals, or any other organic
material. In addition to this, feeding strategies can also be characterized
by the size or nature of the food consumed. Microphages feed on small particulate
materials, macrophages consume large pieces of food or whole organisms, and
fluid feeders consume fluids from either plants or other animals. The feeding
mechanisms used by microphages are further characterized by where they find
the particulate food. If it's suspended in water, they are suspension, or filter,
feeding. If the particles are part of the substrate, then they are deposit,
or substrate, feeders. The small, suspended particles may be algae, microphagous
herbivores, or small invertebrate larvae, microphagous carnivores. Fluid feeders
that get their meal from the surface of an animal are ectoparasites; those that
live inside feeding on blood and body fluids are endoparasites. Both types of
parasites are special cases of the carnivorous feeding strategy.
Why is it important that the events of sperm transfer and fertilization be
separated in a monoecious organism? (p. 47) If sperm transfer and fertilization were not separated, there's a possibility
that a monoecious organism could fertilize its own eggs. One of the advantages
of sexual reproduction is that offspring inherit half of their genes from each
parent, and with this comes, among other things, variation that would not occur
if the monoecious organism used their own sperm to fertilize their eggs.
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2003 McGraw-Hill Higher Education