A graduate student finds an organism in a pond and thinks it is a freshwater sponge. A postdoctoral student thinks it looks more like an aquatic fungus. How can they decide whether it is an animal or a fungus?
Look for cell walls under a microscope.
The earliest ancestors of about half of all extant animal phyla can be traced back to the _____ explosion.
Cambrian
Which of the following is radially symmetrical?
a doughnut
Gastrulation is the process that directly forms the _____.
primary germ layers
Which of the following is NOT a characteristic of all animals?
They have tissues, organs, and organ systems.
An important trend in animal evolution was cephalization. An animal is said to show cephalization when it _____.
has an aggregation of sensory neurons at the anterior end
Which of the following animals does NOT have a body cavity?
flatworm
During embryological development, the anus forms before the mouth in _____.
humans
Which of the following statements is correct?
All animals share a common ancestor.
What is the key difference between a coelom and a pseudocoelom?
Only a coelom is fully lined with mesoderm tissue.
The distinction between sponges and other animal phyla is based mainly on the absence versus the presence of
true tissues.
Acoelomates are characterized by
a solid body without a cavity surrounding internal organs.
The animal phylum most like the protists that gave rise to the animal kingdom is _____.
Porifera (sponges)
Which of the following is a characteristic of cnidarians?
gastrovascular cavity
Which of the following is characteristic of the phylum Platyhelminthes?
They are dorsoventrally flattened. (Platyhelinthes are flatworms)
Some species of rotifers consist solely of females. Their method of reproduction is described as _____.
parthenogenesis
Members of the phylum Mollusca _____.
are soft-bodied and often covered by a shell
Which of the following is true of annelids?
They perform gas exchange across their skin.
A marine biologist dredges up a small animal from the bottom of the ocean. It is uniformly segmented, with short, stiff appendages and soft, flexible skin. It has a complete digestive system and a closed circulatory system, plus multiple true coeloms. Bas
annelid
What structure is responsible for gas exchange in most spiders?
book lungs
Which of the following are thought to be most closely related to humans?
sea stars (both deuterostomes and both love finding nemo)
What evidence suggests that vertebrates are more closely related to echinoderms than are any other invertebrate phyla?
Shared DNA sequences
A land snail, a clam, and an octopus all share
a mantle.
Which phylum is characterized by animals that have a segmented body?
Arthropoda
The water vascular system of echinoderms
functions in locomotion and feeding.
Which of the following combinations of phylum and description is incorrect?
Porifera-gastrovascular cavity, coelom present
Which of the following is NOT a diagnostic feature of the Chordata?
vertebrae
Which of the following chordates is most likely to look least like other chordates?
adult tunicate
A unique feature of craniates is _____.
the neural crest
What do lampreys, sharks, snakes, turtles, and cats have that a hagfish lacks?
vertebrae
Jaws evolved _____.
by modification of the skeletal rods that previously supported the anterior pharyngeal gill slits
The diagnostic feature of Chondrichthyes is _____.
an endoskeleton of calcified cartilage (chondrichthyes are sharks)
Most members of which of the following groups are most closely associated with a wet or moist environment?
amphibians
Listed below are four adaptations of terrestrial vertebrates. Which is a characteristic only of truly terrestrial animals with no need to return to water at any stage of the life cycle?
amniotic eggs (can be in dry environments bc shell)
There are three major groups of mammals, categorized on the basis of their _____.
method of reproduction (Monotremes are egg-laying mammals, marsupials are pouched mammals, and eutherians are placental mammals.)
Identify the correct statement(s) about animal classification.
Craniates have a head and neural crest cells
Which of the following chordate groups include(s) humans?
(all of them)
- Gnathostomes
- Hominins
- Amniotes
Vertebrates and tunicates share
a notochord and a dorsal, hollow nerve cord.
Which of the following could be considered the most recent common ancestor of living tetrapods?
a sturdy-finned, shallow-water lobe-fin whose appendages had skeletal supports similar to those of terrestrial vertebrates
Chordate pharyngeal slits appear to have functioned first as
suspension-feeding devices.