Typical animal embryos have ________,
or external cell layer, and ________, which lines the digestive tract.
an ectoderm . . . an endoderm
During the Cambrian explosion
approximately 542 million years ago,
diversified in the oceans over a period of about 15 million years.
Most of the animals alive today
Which of the following animals displays radial
A true coelom is best described as
a body cavity that
is fully lined by tissue derived from the mesoderm.
A dog's head is at its ________ end and
its belly is its ________ surface.
. . . ventral
A typical sponge is best described as
sessile suspension feeder with no true tissues or body symmetry.
Tapeworms are similar to fungi because
feed by absorption.
You find a wormlike, soft-bodied adult
animal in a mud flat. It is bilaterally symmetrical, is segmented, has a true
coelom, and has a complete digestive tract. Based on these characteristics,
what phylum does the animal represent?
Animals that are segmented and have
jointed appendages and an exoskeleton are members of the phylum
The most numerous, diverse, and
widespread animals are the
Which of the following groups has a
series of similar segments that make up most of the body?
Which of the following groups includes
both spiders and horseshoe crabs?
Most adult insects have three major
body parts or sections. They are the
thorax, and abdomen
The flexible, longitudinal rod that is
located between the digestive tract and the nerve cord in chordates is called
Which of the following features is
unique to chordates?
Which of the following is an
Human skin color likely represents a
locally adapted compromise between
the need to block
UV radiation that destroys folate and the need to synthesize vitamin D.
________ is thought to have played a
crucial role in the evolution of human speech.
All humans alive today have inherited
their mitochondrial DNA from some individual female common ancestor. Studies
indicate this woman probably lived about ________ years ago, when fossil
evidence indicates Homo sapiens
was restricted to ________.
. . . Africa
Fossil and genetic evidence strongly
support the idea that modern humans
derive from a single African lineage that spread from there into other parts of
the world starting about 60,000 years
According to the fossil record, the
genus Homo first arose in
Hominid fossil footprints that are
obviously bipedal date to about ________ years ago.
Human DNA and chimpanzee DNA
by about 1%.
Our closest relatives, the ________,
exhibit several behaviors that closely resemble those of humans.
________ spend almost all of their time
on the ground, instead of in trees.
The forward-facing eyes shared by all
primates help them in
as they navigate through forests.
Which of the following organisms is a
hair and mammary glands.
Which of the following adaptations
allowed reptiles to complete their life cycles on land?
The most ancestral extant tetrapods are
________ derived from ________.
. . . lobe-finned fishes
The first vertebrate with a head and
skull probably resembled a
Mammals exhibit many examples of traits
that are shared among species that are adapted to life in similar environments
and ecological niches. Examples include several species scattered around the
world that resemble anteaters. Like anteaters, they have long snouts and
tongues, stout claws, and other features that suit them to eating ants and
termites. Yet these species are only distantly related, and each has an
ancestor that does not fit the "anteater stereotype." These are
The duck-billed platypus and other
monotremes differ from other mammals in that they
Which of the following is most likely
to be responsible if, when your blood sugar level rises, the level of sugar
goes back down?
homeostatic mechanism based on negative feedback
is the maintenance of a constant
Fingernails are a component of the
The respiratory system includes all of
the following structures except the
Which of the following tissues can
currently be produced artificially and has been successfully used in human
Which type of tissue forms a
communication and coordination system within the body?
Smooth muscle is responsible for
involuntary body activities.
What kind of connective tissue has an
extracellular liquid matrix called plasma?
Which of the following is a type of
both external and internal body surfaces.
Which of the following is a major
category of animal tissue?
Structure in the living world is
organized into hierarchical levels. Which of the following lists these from least inclusive to most inclusive?
cell, tissue, organ, organ system, organism
An organ system consists of
group of coordinated tissues.
A physiologist is a biologist who
function of body parts.
The connection between structure and ________ is
a basic concept of biology
1. Which of the following is associated
with a reduced risk of
high levels of HDL
1. Which of the following diseases is
associated with obesity?
1. A food label indicates that the
contents of a product contain 12 grams of total carbohydrate per serving, 7
grams of sugar per serving (simple carbohydrate), and 2 grams of fiber per
serving. How many grams of digestible complex carbohydrate are there per serving?
1. The essential amino acids
must be obtained from the food
1. A material that must be ingested in
preassembled form because the animal cannot synthesize it is
an essential nutrient.
1. Organisms suffering from
malnourishment have a diet deficient in
one or more essential nutrients
1. All animals must obtain ________
from outside sources.
fuel to power body activities
1. Absorption of water is a major
function of the
1. Nutrients absorbed by the intestines
move directly to the liver, which
converts excess glucose to glycogen
1. Which of the following nutrients is
digested only after it reaches the small intestine?
1. Which enzyme breaks large
polypeptides into smaller polypeptides?
1. Bile produced in the liver is stored
in the ________ before entering the intestine.
1. Which of the following is important in
the digestion of lipids?
1. What is the main digestive function
of the pancreas?
to produce digestive enzymes and a bicarbonate buffer
1. Epithelial cells lining the
intestine have surface projections that increase nutrient absorption. These
projections are called
1. In the digestive system, most
nutrient absorption occurs in the
1. Most gastric ulcers are caused by
1. Heartburn is usually caused by the
reflux of chyme from the stomach into the lower
1. The function of the pyloric
sphincter is to
periodically release chyme into the duodenum in
The stomach mixes
food with secretions of the stomach wall to form
1. The secretory parietal cells of the
stomach are responsible for producing
cells that line the stomach
lubricate and protect the stomach lining
1. The epiglottis is a
flap of cartilage that flips down to cover the entry
to the trachea during swallowing
Human saliva performs all of the following functions except
1. The digestion of carbohydrates
begins in the mouth. What is the name given to the starch-digesting enzyme
secreted by salivary glands?
1. Digestion begins in the
1. Regulation of the passage of food
from the stomach is accomplished by
1. Smooth muscle propels food through
the alimentary canal by a process called
1. Which of the following correctly
lists the order of the parts of the human digestive system, from first to last
contact with food matter?
oral cavity, pharynx, esophagus, stomach, small
intestine, large intestine
1. An animal digestive tract that
consists of two openings (a mouth and anus) is called
the alimentary canal.
1. Through digestion, nucleic acids are
broken down into
1. Through digestion, polysaccharides
are broken down into
1. What happens to nutrient
macromolecules in an animal's digestive tract?
Nutrient macromolecules are digested into monomers
1. During which of the following stages
of food processing is undigested material removed from the digestive tract?
1. Digestion is the
chemical and mechanical breakdown of food for
absorption into the body.
1. Most animals are
1. Which of the following act mainly to
regulate salt and water balance?
1. Which of the following is a function
release of glucose from the liver
1. Which of the following glands
secretes hormones that enable the body to respond to stress?
1. Which of the following glands is
located nearest the kidneys?
1. What is the metabolic abnormality
that underlies the characteristic symptoms of diabetes mellitus?
an inability of the body's cells to absorb enough
glucose from the blood
1. Which of the following hormones
causes glucose release and, consequently, a rise in the concentration of sugar
in the blood?
1. Which of the following statements
best describes the relationship of insulin to glucagon?
They are antagonistic hormones.
1. Which of the following pairs of
hormones have opposite effects?
parathyroid hormone and calcitonin
1. Which of the following processes
depends on the presence of appropriate calcium levels in the blood and
transmission of nerve signals from cell to cell
1. Which gland requires the element
iodine to produce its hormones?
1. Which of the following hormones is
released by neurosecretory cells extending from the hypothalamus?
1. Which of the following statements
about glands and hormones is true?
The anterior pituitary is composed of endocrine cells.
1. Which of the following is an
endocrine gland that raises blood calcium levels?
1. Which of the following options
correctly pairs an endocrine gland or hormone with an aspect of metabolism that
insulin = regulates blood glucose levels
1. Which of the following statements about
steroid hormones is true?
Steroid hormones bind to specific receptor proteins
and the complex acts as a gene activator
1. Neurosecretory cells
participate in the nervous and endocrine systems.
1. Nonsteroid hormones are synthesized
1. Which of the following options lists the
sequence of events in the cell-signaling process in the correct order?
transduction, cell response
1. Why must some hormones bind to a
membrane receptor on a target cell's surface in order to activate it?
because they cannot cross cell membranes
1. The result of binding a signal
molecule to its receptor is
1. A target cell that is affected by a
particular steroid hormone would be expected to have
an intracellular receptor protein that binds the
1. Steroid hormones are lipids made from
1. Compared to the endocrine system,
the nervous system
has a faster response, but the signal does not last as
1. Hormones are chemicals produced by
the endocrine system that