Exam 3 Flashcards
what are traits of true sponges?
lack true tissues, can regenerate, filter feeders, sedentary
Cnidarians differ from sponges in that cnidarians have…
true tissues, motile forms, and tentacles
What is most consistent with the hypothesis that the cambrian explosion was caused by the rise of predator-prey relationship?
increased incidence of hard parts in the fossil record
What are characteristics of the body cavity?
acts as a hydrostatic skeleton in soft bodied animals, cushions suspended organs and preventing internal injury, a space lined by mesoderm in coelomates, allows internal organs to enlarge and move independently of the outer body wall
What is true about the animal tissues that develop from embryonic germ layers?
a pseudocoelom has the same functions as a true coelom, in a coelomate the tissue lining the inner side of the body cavity arises from the same germ layer as the tissue lining the outer side of the body cavity, and a diploblast has no mesoderm
what is NOT a characteristic of all animals?
they have tissues, organs, and organ systems
The animal phylum most like the protists that gave rise to the animal kingdom is _____.
porifera
Which of the following is a characteristic of cnidarians?
gastrovascular cavity
The earliest ancestors of about half of all extant animal phyla can be traced back to the ______ explosion
cambrian
An important trend in animal evolution was cephalization. An animals said to show cephalization when it_____
has an aggregation of sensory neurons at the anterior end
Members of the phylum Mollusca_____
are soft-bodied and often covered by a shell
what is thought to be most closely related to humans?
sea stars
What are NOT diagnostic features of the Chordata? a hollow dorsal nerve cord vertebrae muscular, post-anal tail notochord pharyngeal slits or clefts
vertebrae
The diagnostic feature of Chondrichthyes is ______
an endoskeleton of calcified cartilage
Most members of which group are most closely associated with wet or moist environment?
amphibians
what characteristic only of truly terrestrial animals with no need to return to water at any stage of the life cycle?
amniotic egg
There are three major groups of mammals, categorized on the basis of their _______
method of reproduction
Which chordate group lacks a post-anal tail and a notochord as adults?
tunicates
The common ancestor of all these chordate groups EXCEPT the \_\_\_\_ probably had paired appendages mammals amphibians lampreys ray-finned fishes reptiles
lampreys
What is the only chordate group that has hair?
mammals
what is the key difference between a coelom and a pseudocoelom?
only a coelom is fully lined with mesoderm tissue
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
Gastrulation is the process that directly forms the _____
primary germ layers
Which of the following animals does NOT have a body cavity? flatworm clam nematode earthworm mouse
flatworm
During embryological development, the anus forms before the mouth in___
humans
Jaws evolved ______
by modification of the skeletal rods that previously supported the anterior pharyngeal gill slits
Which of the following clades contains the greatest number of animal species? chelicerats bilaterians sponges deuterosomes insects
bilaterians
what is thought to have let to the increasing complexity of the arthropod body plan?
changes in regulation of Hox genes for body segmentation
which of the following statements would be least acceptable to most zoologists?
a. the extant lancelets are contemporaries, not ancestors, , of vertebrates
b. the first fossils resembling lancelets appeared in the fossil record around 530 million years ago
c. recent work in molecular systematics supports the hypothesis that lanceletes are the basal clade of chordates
d. the extant lancelets are the immediate ancestors of the fishes
e. lancelets display the same method of swimming as do fishes
d. the extant lancelets are the immediate ancestors of the fishes
If the osteichthyan clade was exclusively made up of ray-finned and lobe-finned fish, the grouping would be…
paraphyletic
Why is a Tikataalik not classified as a tetrapod?
because it had gills
Complete metamorphosis, in which juveniles and adults are dissimilar, was also observed in insects. What is an advantage of metamorphosis?
adults and juveniles do not compete for the same food sources and adults and juveniles have different predatory pressures
All of the following are characteristics of members of the class Aves except one. Select the exception. Ectothermy No urinary bladder Bones lightened by numerous air spaces Feathers Lack of teeth
Ectothermy
what are functions of the hypothalamus?
synthesizes some hormones that are released into the blood vessels bound for another gland, integrates nervous and endocrine system, and synthesizes oxytocin and ADH
functions of the posterior pituitary
is an extension of the hypothalamus and releases oxytocin
functions of the anterior pituitary
synthesis and releases PRL, synthesizes an releases TSH, and regulated by hormones released into portal blood vessels
If surgical hypothyroidism would likely affect prolactin levels?
thyroid hormone levels decrease, TRH levels increase, and PRL levels increase
Which term describes a mechanism by which the internal conditions of an organism are kept at set values without regard to the external conditions? negative feedback conformational homeostasis thermoregulation regulatory homeostasis
regulatory homeostasis
Which of the following actions is not a function of the epithelium?
Creates an internal environment that is different from the external environment.
Allows the internal environment to alter its conditions to match those of the external environment.
Regulates the excretion of waste.
Controls the exchange of nutrients between the internal and external environments.
allow the internal environment to alter its conditions to match those of the external environment
True or False. Organisms must maintain homeostasis because optimal enzyme activity is achieved within a very narrow range of conditions
true
Which component of a homeostatic system sends instructions based on sensory information? sensor integrator set point effector
integrator
Which component of a homeostatic system perceives changes in some parameter of the environment? sensor integrator set point effector
sensor
Which of the following actions to warm a homeothermic body? shivering panting sweating dilating blood vessels
shivering
The four major categories of tissues are_____
nervous, epithelial, muscle, and connective
Homeostasis is the…
maintenance of a relatively constant and optimal internal environment
Negative feedback is a method of homeostatic control that____
ensures that conditions in an organism do not vary too much above or below their set points
A countercurrent heat exchanger enables an animal to ____
reduce the loss of body heat to the environment
Urine formed by a kidney collects in the _____ before being drained from the kidney by the _____ and transported to the _____
renal pelvis… ureter… urinary bladder
The _____ are the major blood vessels transporting blood to the kidneys.
renal arteries
The outer part of the kidney is the _____
cortex
what is the functional unit of the kidney?
nephron
Terrestrial animals are ___
osmoregulatory that must obtain water from the environment
Birds, insects, and many reptiles excrete nitrogenous waste in the form of uric acid, which ____
reduces water loss compared to other nitrogenous wastes, but requires more metabolic energy to produce