Blue-footed boobies have webbed feet and are comically clumsy when they walk on land. Evolutionary scientists view these feet as
the outcome of a tradeoff: webbed feet perform poorly on land, but are very helpful in diving for food.
Which of the following statements would Darwin have disagreed with?
Descent with modification occurs through inheritance of acquired characteristics
Broccoli, cabbages, and Brussels sprouts all descend from the same wild mustard and can still interbreed. These varieties were produced by.
Humans share several features with salamanders. Certain genes and proteins are nearly identical between the two species: both species have four limbs with a similar skeletal structure; the species vestigial tailbone. In evolutionary terms, these are examples of
Darwin was the first person to draw an evolutionary tree, a diagram that represents
evidence- based hypotheses regarding our understanding of patterns of evolutionary descent.
Which sentence best describes the true nature of natural selection?
Heritable traits that promote reproduction become more frequent in a population from one generation to the next.
An elk herd is observed over many generations. Most of the full-grown bull elk have antlers of nearly the same size. The average antler size remains constant over the generations. Which of the following effects probably accounts for the situation?
A women struggling with bacterial illness is prescribed a months supply of a potent antibiotic. She takes the antibiotic for about 2 weeks and feels much better. Should she save the remaining two week supply or should she continue taking the drug?
She should continue taking the drug until her immune system can completely eliminate the infection. Otherwise the remaining bacteria in her system may recover, and they will probably be resistant
The sickle-cell allele produces a serious blood disease in homozygotes. Why doesn't natural selection eliminate this allele from all human populations?
In populations were endemic malaria is present, heterozygotes have an important advantage: They are resistant to malaria and therefore are more likely to survive and produce offspring that carry the allele.
Frequency-dependent selection, as seen in the case of the scale-eating fish in lake Tanganyika, tends to
maintain two phenotypes in a dynamic equilibrium in a population
During which of the following stages of food processing is undigested material removed from the digestive tract
An alimentary canal is best defined as
a tube-shaped compartment for the transport, digestion, and absorption of food
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
Digestion begins in the
The mucous-producing cells that line the stomach
lubricate and protect the stomach lining
In the digestive system, most nutrient absorption occurs in the
organisms suffering from malnutrition may have a diet deficient in
one or more essential nutrients
which of the following is a hormone produced by adipose cells that help to control appetite?
Animals that maintain internal body temperature using heat generated by their own metabolism are called
To enhance heat loss, humans sweat, an adaption known as
sweating commonly results in dehydration. Of the choices listed, which would be the best option for rehydration after intense exercise?
mammals have evolved a sophisticated mechanism for eliminating nitrogenous wastes that involves
forming urea and storing it in concentrated solution
whats is the name of the functional unit of the kidneys
during production of urine, a major function of the kidney is
what is the function of antidiurectic hormone?
to increase water reabsorption
when a salmon moves from the ocean to a freshwater environment, you would expect its urine volume to _______ and its rate of salt absorption to ______.
In a dialysis machine, wastes are removed from blood plasma by process of
through which of the following structures does urine leave the bladder?
increased brain size had many benefits for early humans. one example is
complex social structure with the ability to adapt to changing environments
when comparing the differences between human and chimpanzee DNA
the differences are generally found in the gene switches that determine when and how genes are expressed.
walking upright has both pros and cons. some of the pros of walking upright include
looking large to predators, the ability to harvest more food, the ability to carry young.
homo erectus was the first early human to spend most of its time walking upright
tool use is uniquely human
chimpanzees are humans closest living relatives
lower back pain can be attributed to walking upright, which formed the curvature at the base of the spine
Humans and chimpanzees have 90% identical genome sequences
Darwins ideas about evolution were formed after observing marine iguanas on the galapagos islands
____ genes are responsible for coding for self-proteins.
A molecule that can elicit an adaptive immune response is called
Medullary breathing centers directly sense and respond to
blood pH and CO2 concentration
which part of the diagram shows the alveoli?
Air leaving human lung during exhalation contains
carbon dioxide and unused oxygen
during gas exchange, body cells
release CO2 and take in O2
As blood moves away from the heart towards the tissues, the relative size of blood vessels _____, the blood pressure ______, and the velocity of blood flow _______.
which of the following is a function of the nasal cavities in humans?
warming inhaled air
arteries are distinguished from veins based on all of the following features except
the amount of oxygen present in the blood
The main function of the AV node is to
relay a signal for the ventricles to contract
The maximum amount of air that a human can inhale and exhale is called the
Which of the following cell types is responsible for the cell-mediated immune response?
Natural Killer Cells
attack virus-infected cells by releasing chemicals that lead to the death of the cell
Oxygen moves from blood into the interstitial fluid and then to body cells because
it diffuses from a region of higher partial pressure to a region of lower partial pressure
which of the following distingueshes the secondary immune response from the primary?
The secondary response is faster and stronger
which of the following choices best describes a plasma cell?
It is a differentiated B cell
Oxygen-poor blood is carried from the heart of a mammal to the lungs via the
What type of blood vessel is solely responsible for exchange between the blood and the interstitial fluid?
which of the following helps activate our nonspecific (innate) defense system?
A primary immune response is
the immune response elicited by the first exposure of lymphocytes to a particular antigen
cardiac output is defined as the volume of blood pumped by an ____ each time it contracts
Which of the following types of cells does HIV preferentially infect?
helper T cells
The reason animals need continuous supply of oxygen is
obtain energy from their food
after binding to an infected cell, the cytotoxic T cell
releases a protein called perforin
what part of the human brain contains the primary breathing control center?
multipotent stem cells found in the red marrow inside bones
can differentiate into all blood cells and platelets
An adult humans red blood cells are formed in the
which blood vessels have the thinnest walls
labored breathing, coughing, lung infections, and respiratory failure are characteristics defining
chronic obstructive pulmonary diseases
which of the following contributes to gas exchange in the human fetus
the stronger attraction that fetal hemoglobin has for oxygen when compared to adult hemoglobin
blood clots are formed by platelets and the plasma protein
which of the following statements about mammalian circulatory systems is false?
The left side of a mammals heart sends blood to the lungs
The liquid part of blood is called
what prompts a newborn baby to start to breather?
an increase in the concentration of oxygen in the baby's blood
which of the following options correctly lists the direction of carbon dioxide travel as it leaves the body?
alveoli, bronchioles, bronchi, trachea, larynx, pharynx
which of the following is a function of the circulatory system?
transporting nutrients to body cells
The oxygen-carrying component in red blood cells is
which of the following wander through the interstitial fluid and consume any bacteria and virus-infected cells they encounter?
anaphylactic shock is an example of an
which of the following cells are phagocytes?
monocytes and neutrophils
which of the following can contribute to high blood pressure?
blood flow through capillaries is controlled by
precapillary sphincters and smooth muscle in the walls of arterioles
what type of immune response is always disadvantageous to a person?
which of the following cell types is responsible for the humoral immune response?
The human lymphatic system consists of all of the following structures except the
The basic function of the activated T cells is to battle
pathogens that have alreasy entered body cells
one kind of vaccine consists of
a harmless variant strain of a disease-causing microbe
cigarette smoke can affect the white blood cells that reside in our lungs, whose purpose is to
engulf foreign particles
which of the following animals requires the largest and most complex lungs proportional to its overall body size?
Plasma proteins are involved in all of the following activities except
The autonomic nervous system
regulates the internal environment of the body
The central communication conduit between the brain and the rest of the body is the
functionally, the muscle fibers fundamental unit for contraction is the
muscles are connected to the bones by
a tennis player serving the ball uses fast muscle fibers. The ATP needed to accomplish this would come from
The signal that crosses a synapse is stopped when
the neurotransmitter is enzymatically broken down or transported back to the signaling cell
Bone is composed of
living cells that secrete a surrounding matrix
the neurotransmitter found at the synapse between nerves and human skeletal muscle cells is
which division of the human nervous system carries signals to skeletal muscles?
action potentials normally travel along an axon
away from the cell body
According to the sliding filament model of muscle contraction, a sarcomere contracts when its
thin filaments slie towards each other across its thick filaments
work in antagonistic pairs
nervous system effector cells
include muscle cells and gland cells
which of the following statements regarding the brain is true
the blood-brain barrier helps to maintain a stable chemical environment for the brain
the gap between the transmitting and receiving neurons in a chemical synapse is known as the
The relationship between spinal nerves and the spinal cord is most like the relationship between
an interstate highway and the many roads that intersect with it via on- and off- ramps
which of the following structures constitutes part of the axial skeleton
The calcium that triggers muscle contraction is stored in
the endoplasmic reticulum
which of the following statements regarding exercise is true
the main source of energy during aerobic exercise is ATP from aerobic respiration
Osteoporosis is characterized by
low bone mass and structural deterioration of the bone tissue.
what part of the neuron carries signals toward the part of the cell that houses the nucleus
one neurotransmitter associated with sleep, mood, attention, and learning is
Muscles that are constantly active, such as those maintaining our body posture, having a high proportion of
slow, fatigue-resistant fibers.
Parkinsons disease is associated with a deficiency in
which of the following statements regarding the nervous system is true
motor neurons convey signals from the CNS to the effector cells
which of the following statements about resting potential is true
the sodium-potassium pump contributes to the resting membrane potential
changes occur within a sarcomere during muscle contraction. one change is that the
Z lines move closer together
The shoulder joint where the humerus meets the shoulder gridle is an example of
a ball and socket joint
a motor unit is
a motor neuron and all of the muscle fibers it controls
The speed of impulse conduction along an axon may be increase by
a myelin sheath
Neurotransmitters that open Na+ channels and trigger action potentials in receiving cells are called
The enteric division of the autonomic nervous system consists of neurons in the digestive tract, the gallbladder and
a thick filament consists of
which of the following statements about locomotion is true
locomotion requires animals to overcome friction and gravity
multiple sclerosis results from an autoimmune disease that primarily involves
destruction of the myelin sheath
which of the following statements best describes the power stroke of muscle contraction?
the myosin head bends, pulling the thin filament toward the center of the sarcomere
which part of a bone contains mostly stored fat?
yellow bone marrow
during transmission across a typical chemical synapse
neurotransmitter molecules bind to receptors in the receiving cells plasma membrane
the functional unit of the nervous system is the
in all vertebrates, the brain consists of the
the sequence of events that cause a muscle to contract can be summed up in the correct order as
detach, extend, attach, pull
the contacting surfaces of a moving joint, such as your hip joint, consist of
action potentials relay different intensities of information due to the
frequency of action potentials relative to the strength of the stimulus
which of the following statements about skeletal muscle fibers is true
each muscle fiber contains actin and myosin
the two major anatomical divisions of the nervous system are the
central nervous system and peripheral nervous system
Which of the following statements regarding sexual reproduction is true?
Sexual reproduction generates greater genetic variation than asexual reproduction.
In which part of the human female reproductive system does fertilization normally take place?
Human testes are positioned in an external sac rather than in the abdominal cavity
so the testes can be kept cooler than the body's interior.
Which of the following produces a thick fluid containing fructose, which is used for energy by sperm?
Which of the following statements comparing spermatogenesis and oogenesis is true?
Men, but not women, can produce gametes throughout their lives.
Which of the following STDs is caused by a virus that can also cause cancer?
Sterilization, in which the sperm is surgically prevented from reaching the egg, is accomplished by
tubal ligation or vasectomy.
The function of a sperm cell's acrosome is to
carry enzymes that help the sperm penetrate the egg.
Which of the following serves as an impenetrable barrier that prevents more than one sperm from fertilizing an egg?
the vitelline layer
Which of the following occurs during the process of labor?
positive feedback involving oxytocin and prostaglandins
Mendel conducted his most memorable experiments on
An insect that has the genotype EeGGcc will have the same phenotype as an insect with the genotype _____.
In an individual of genotype Aa, where are the A and a alleles physically located?
One allele is on one chromosome, and the other is in the same position (locus) on the homologous chromosome.
The phenotypic ratio resulting from a dihybrid cross showing independent assortment is expected to be
Imagine that we mate two black Labrador dogs with normal vision and find that three of the puppies are like the parents, but one puppy is chocolate with normal vision and another is black with PRA (progressive retinal atrophy, a serious disease of vision). We can conclude that
the alleles for color and vision segregate independently during gamete formation.
Imagine that long fins in zebrafish is a dominant trait. A breeder wants to set up a breeding program beginning with homozygous dominant long-finned fish. If she obtains a handful of the long-finned fish, how can she tell which if any of these are homozygous for the trait?
Cross the long-finned fish with short-finned fish; if the offspring are all long-finned, the long-finned parent is homozygous.
Dr. Smith's parents have normal hearing. However, Dr. Smith has an inherited form of deafness. Deafness is a recessive trait that is associated with the abnormal allele d. The normal allele at this locus, associated with normal hearing, is D. Dr. Smith's parents could have which of the following genotypes?
Dd and Dd
A carrier of a genetic disorder who does not show symptoms is most likely to be ________ to transmit it to offspring.
heterozygous for the trait and able
All the offspring of a cross between a red-flowered plant and a white-flowered plant have pink flowers. This means that the allele for red flowers is ________ to the allele for white flowers.
A woman has been trying to conceive for several years, unsuccessfully. At a fertility clinic, they discover that she has blocked fallopian tubes. Using modern technologies, some of her eggs are removed, fertilized with her husband's sperm, and implanted into her uterus. The procedure is successful, but the couple discovers that their new son is color-blind and has blood type O. The woman claims that the child can't be theirs since she has blood type A and her husband has type B. Also, neither parent is color-blind, although one grandparent (the woman's father) is also color-blind.
As a genetic counselor, you would explain to the parents that
it is possible for the baby to have type O blood, since type O is inherited through a dominant allele.
has been around since the dawn of civilization.
After DNA fragments with matching sticky ends are temporarily joined by complementary base-pairing, the union can be made permanent by the "pasting" enzyme
The type of recombinant bacteria most often used to mass-produce genes is
The advantage of being able to clone the gene for human insulin is that
human insulin is less likely to cause harmful side effects than cow, pig, or horse insulin.
Which of the following has not been a significant issue in the creation of genetically modified (GM) organisms?
the fact that GM organisms cannot be modified to prevent them from reproducing once they pass beyond the experimental stage
What is the preferred name of the technique used to determine if DNA comes from a particular individual?
Gel electrophoresis sorts DNA molecules on the basis of their
What is the current standard tool used for DNA profiling by forensic scientists?
Which of the following statements about genomics is false?
DNA technology limits genomic studies to prokaryotes.
In "Cracking Your Genetic Code," what type of cancer was being targeted with drugs based on the genome of the cancer cells?