Exam 5 Flashcards
(205 cards)
All animals except sponges have _____, groups of cells that work together to perform a specific function
tissues
One key adaptation of animals was the evolution of an ____ ____, a fluid-filled gap between the outer wall of the body and the outer wall of the digestive system
body cavity
Cnidarians are the only animal phylum to display ____ ____, meaning that their bodies can be divided any way through the center point to yield two even halves. All other adult animals display ____ ____, meaning that their bodies can only be sliced lengthwise through the midline to produce two even halves
radial symmetry; bilateral symmetry
All animals eat other organisms in order to gain building materials for the body. This makes them _____, since they obtain necessary energy and chemical building blocks from the environment
heterotrophs
All animals are _____, organisms with cells that are relatively large, complex, and contain membrane-enclosed organelles such as the nucleus
eukaryotes
which of the following is a defining characteristic of animals but not of plants?
Animals, but not plants, are heterotrophs
the animal phyla can be divided into three separate clades based on which characteristic
the symmetry of the body
what happened during the cambrian explosion
there was a rapid diversification of animal forms
most animals fall into one of how many phyla?
9
how many of the animal phyla include single-celled animals
0
What defines radial symmetry?
any plane of symmetry passing through the center of the organisms split it into equal halves
being a heterotroph means
obtaining your food by eating other organisms
the first animals evolved from ____
protists
which specialized structures are unique to the cnidarians
stinging cells
sponges are mostly found in ____
marine ecosystems
which body form of the cnidarians is sessile
the polyp
what do sponges and cnidarians have in common
none of the above are characteristics that sponges and cnidarians
which of the following best describes sponges?
they are asymmetrical, lack tissues, and do not move
which of the following best describes cnidarians
they have radial body symmetry, tissues, and stinging cells
which characteristic do all mollusks have?
mantle
flatworms are most closely related to the ______
annelids
serial repetition of segments is a defining characteristic of which worm phylum
annelids
roundworms are more closely related to arthropods than to flatworms
true
which arthropod subgroup includes the spiders?
arachnids