Bio final exam
Blue flower color (B allele) is dominant to white (b allele). If a population of plants contains white flowers (bb) at a frequency of 0.04, what is the frequency of the heterozygous genotype?
.80
in the hardy-weinberg equation, p + q = ____, where p and q represent ____.
1, allele frequencies
most biological q values are between ___ and ____
2; 3
Endosperm tissue of angiosperms has what ploidy level?
3n
The large number of alveoli in mammalian lungs, the numerous lamellae in fish gills, the papulae of echinoderms, and the extensive tracheal system of insects are all adaptations that optimize what factor in the formula for Fick's Law of Diffusion?
A
Natural selection is based on all of the following except A. individuals who survive longer tend to leave more offspring than those who die young. B. individuals adapt to their environments and thereby, evolve. C. populations tend to produce more individuals than the environment can support. D. the best-adapted individuals tend to leave the most offspring.
B
the hypothalamus and thalamus develop from the
Dicenphalon
this is a protein that help display antigen to T cells or B cells, displays epitopes on cell surface
MHC
interactions between macrophages and lymphocytes are coordinated are
MHC proteins
A group that includes the common ancestor and some, but not all, of its descendants is considered to be A. paraphyletic. B. polyphyletic. C. monogamous. D. monophyletic.
a
Angiosperm double fertilization is so-called because it features the formation of a) one embryo involving one sperm cell and and an endosperm involving a second sperm cell b) two embryos from 2 sperm cells and 2 eggs c) two embryos from 1 egg and 2 sperm cells d) one embryo from one egg fertilized by 2 sperm cells
a
Chordin is an organizer protein found only in the dorsal regions of frog embryos. Removing chordin would most likely disrupt the determination of which structure? A) central nervous system B) lungs C) digestive system D) kidneys
a
In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.3. What is the frequency of individuals that are homozygous for this allele? Looking for q2 A. 0.09 B. 0.49 C. 0.9 D. 0.049
a
It can be very difficult to select an angle for sneaking up to a grasshopper to catch it because grasshoppers have A. compound eyes. B. binocular vision.C. eyes with multiple fovea.D. camera-like eyes with multiple fovea.
a
Mammals and birds eat more often than reptiles. Which of the following traits shared by mammals and birds best explains this habit? A) endothermy B) ectothermy C) amniotic egg D) terrestrial
a
Spina bifida is one of the most prevalent of human birth defects. The defect usually involves the spinal cord or the spinal canal opening tothe outside of the body. In severe cases, movement of the legs may be limited or entirely absent. At which stage of development is this defect likely to occur? A) formation of the neural tube B) formation of the gastrula C) formation of the somites D) formation of the lateral mesoderm
a
The common ancestors of birds and mammals were very early (stem) reptiles, which almost certainly possessed three-chambered hearts (two atria, one ventricle). Birds and mammals, however, are alike in having four-chambered hearts (two atria, two ventricles). The four-chambered hearts of birds and mammals are best described as A. homoplasies B. molecular homologies C. the result of shared ancestry. D. structural homologies.
a
The processes of water flow in xylem and sugar translocation in phloem differ in many respects. Which of the following is nota difference between xylem and phloem transport? A) Water potential gradients are required for xylem transport to occur, but not for phloem transport. B) Xylem transport is a wholly passive process; phloem transport includes active (energy-requiring) processes. C) Cells through which xylem transport occurs are "dead" at maturity; those in phloem transport are "alive." D) Xylem transport always occurs in the same direction; phloem transport does not.
a
The transfer of fluid from the glomerulus to Bowman's capsule A. is mainly a consequence of blood pressure in the capillaries of the glomerulus. B. is very selective as to which sub protein-sized molecules are transferred. C. transfers large molecules as easily as small ones. D. results from active transport.
a
Upon being formed, oceanic islands, such as the Hawaiian Islands, should feature what characteristic, leading to which phenomenon? A. A variety of empty ecological niches, leading to adaptive radiation. B. Overcrowding, leading to rafting to nearby lands. C. Major evolutionary innovations, leading to rafting to nearby continents. D. Mass extinctions, leading to bottleneck effect.
a
Which statement about the beak size of finches on the island of Daphne Major during prolonged drought is true? A. Each bird's survival was strongly influenced by the depth and strength of its beak as the drought persisted. B. The frequency of the strong-beak alleles increased in each bird as the drought persisted. C. Each bird that survived the drought produced only offspring with deeper, stronger beaks than seen in the previous generation. D. Each bird evolved a deeper, stronger beak as the drought persisted.
a
Which tissue type, or organ, is not correctly matched with its germ layer tissue? A) nervous-mesoderm B) muscular-mesoderm C) stomach-endoderm D) skin-ectoderm
a
a freshwater fish tends to _____ water because its body fluids have ____ osmolarity than fresh water has. a) gain; a greater b) lose; a greater c) lose; a lower d) gain; a lower
a
in a frog embryo, gastrulation... a) proceeds by involution as cells roll over the lip of the blastopore b) occurs within the inner cell mass that is embedded in the large amount of yolk c) produces a blastocoel displaced into the animal hemisphere
a
the main source of water necessary for photosynthesis to occur in the leaf mesophyll is _____. A) soil via the xylem B) soil via the phloem C) the atmosphere through the stomata D) the atmosphere through the cuticle
a
which process makes the water potential in a leaf more negative? a) the evaporation of water from the mesophyll cells b) the pressure placed on the leaf by the cuticle c) the movement of water into the leaf by root pressure d) the increased K+ being pumped out of guard cells
a
a paraphyletic group contains...
a common ancestor but not all of its descendants
As compared to the circulatory system of most fishes, the circulatory system of adult amphibians has the advantage of
a partial separation between pulmonary and systemic circulation
immunity that the body develops after it overcomes a disease, or through inoculation (such as vaccination)
acquired immunity
Contact of a sperm with signal molecules in the coat of an egg causes the sperm to undergo:
acrosomal reaction
the ability to recognize and remember specific antigens and mount an attack on them
adaptive immunity
An evolutionary pattern in which many species evolve from a single ancestral species
adaptive radiation
An attraction between molecules of different substances
adhesion
The formation of new species in populations that are geographically isolated from one another.
allopatric speciation
In mammals, gas exchange between the atmosphere and the pulmonary blood occurs in the ________.
alveoli
if a patient has an injury in the brainstem, what would be observed?
an inability to regulate heart function
Convergent evolution creates _____ structures
analogous
The long snout of the giant anteater, Myrmecophaga tridactyla, of South America, and the echidna, Tachyglossus aculeatus, of Australia, are animals of different evolutionary lineages that are both adapted to eating ants. This is an example of
analogous traits
more-primitive characteristic that appeared in common ancestors
ancestral trait
A flowering plant which forms seeds inside a protective chamber called an ovary.
angiosperms
the part of a stamen that contains the pollen.
anther
Pollination begins when pollen is transferred from the ________ to the ________ of a flower.
anther; stigma
which of these characteristics does not promote outcrossing in flowering plants?
apopmixis
Breeding organisms with specific traits in order to produce offspring with identical traits.
artificial selection
"Turgor" is most related to the plant cells'... a) solute potential b) pressure potential c) osmosis d) total water potential
b
5. What is the meaning of Darwin's expression "descent with modification"? A. Descent with modification refers to natural selection. B. Descent with modification refers to evolutionary change over time. C. Descent with modification refers to the partial resemblance of offspring to their parents.
b
A botanist discovers a new species of plant in a tropical rain forest. After observing its anatomy and life cycle, he notes the following characteristics: flagellated sperm, xylem with tracheids, separate gametophyte and sporophyte generations with the sporophyte dominant, and no seeds. This plant is probably most closely related to A. flowering plants B. ferns C. mosses D. gymnosperms
b
Among known plant species, which of these have been the two most commonly occurring phenomena that have led to the origin of new species?1. Allopatric speciation2. Sympatric speciation3. Sexual selection4. Polyploidy A. 1 and 3 B. 2 and 4 C. 2 and 3 D. 1 and 4
b
Among protostomes, which morphological trait has shown the most variation?Hint: The phylogenetic tree on the last page of the exam might be helpful. A) type of symmetry (bilateral vs. radial vs. none) B) type of body cavity (coelom vs. pseudocoelom vs. acoelom) C) number of embryonic tissue types (diploblasty vs. triploblasty) D) direction of gastrulation (protostome vs. deuterostome)
b
An example of ligand-gated ion channels is A. the spreading of action potentials in the heart. B. acetylcholine receptors at the neuromuscular junction. C. action potentials on the axon. D. cAMP-dependent protein kinases.
b
Aquatic species that allow the osmolarity of their tissue fluid to equilibrate with their environment are known as A. osmoregulators. B. osmoconformers .C. osmodependents. D. ionic regulators.
b
Central coordination of vertebrate biological rhythms in physiology and behavior reside in the A. thalamus. B. hypothalamus. C. cerebrum. D. cerebellum.
b
In seed cracker finches from Cameroon, small- and large-billed birds specialize in cracking soft and hard seeds, respectively. If long-term climatic change resulted in all seeds becoming hard, what type of selection would then operate on the finch population? A. Disruptive selection. B. Directional selection. C. No selection would operate because the population is in Hardy-Weinberg equilibrium. D. Stabilizing selection.
b
Individuals of a population that are all born at the same time are known as aA. survivorship.B. cohort.C. population structure.D. demographic pool.
b
Myelinated neurons are most abundant in the A. grey matter of the brain and white matter of the spinal cord. B. white matter in the brain and white matter of the spinal cord. C. white matter of the brain and grey matter of the spinal cord. D. grey matter of the brain and grey matter of the spinal cord.
b
One difference between early development in humans and in Xenopus(frogs) is that _____. A) in humans, there is no formation of the blastula; in Xenopus, the blastula is a critical stage in early embryogenesis B) in humans, blastocysts implant into the uterine wall; there is no implantation in Xenopus C) in humans, gastrulation occurs before blastula formation; in Xenopus, gastrulation takes place immediately after blastula formation D) in humans, neurulation occurs immediately after cleavage; in Xenopus, neurulation is delayed until after gastrulation
b
Organisms with a circulating body fluid that is distinct from the fluid that directly surrounds the body's cells are likely to have A) an open circulatory system. B) a closed circulatory system. C) a gastrovascular cavity. D) branched tracheae.
b
Over time, the movement of people on Earth has steadily increased. This has altered the course of human evolution by increasing A. geographic isolation B. gene flow C. nonrandom mating D. genetic drift
b
Snakes, which lack limbs, evolved from vertebrates that had legs. This is an example of A. convergent evolution. B. an evolutionary reversal. C. a clade. D. a homology.
b
Species that are not closely related and that do not share many anatomical similarities can still be placed together on the same phylogenetic tree by comparing their A. plasmids. B. homologous genes that are highly conserved. C. homologous genes that are poorly conserved. D. mitochondrial genomes.
b
The "motor unit" in vertebrate skeletal muscle refers toA. one actin binding site and its myosin partner. B. one motor neuron and all of the muscle fibers on which it has synapses .C. one sarcomere and all of its actin and myosin filaments. D. one myofibril and all of its sarcomeres.
b
The function of the acrosomal complex during fertilization is _____. A) to block polyspermy B) to dissolve the coating of the egg C) to nourish the sperm mitochondria D) to permit maximum sperm motility
b
The muscles of a recently deceased human can remain in a contracted state, termed rigor mortis, for several hours, due to the lack of A. calcium ions needed to bind to troponin. B. ATP needed to break actin-myosin bonds. C. oxygen supplies needed for myoglobin. D. sodium ions needed to fire action potentials
b
Two fundamental concepts about the ion channels of a "resting" neuron are that the channels A. open and close depending on chemical messengers, and are nonspecific as to which ion can traverse them. B. open and close depending on stimuli, and are specific as to which ion can traverse them. C. is always open, but the concentration gradients of ions frequently change. D. is always close, but ions move close to the channels during excitation.
b
Water potential (ψ) can be thought of as the tendency for water to move from one place to another. In plants, it is made up mainly of solute potential and pressure potential. Hypothetical plant cells A and B are adjacent to each other. The solute potential (ψS) of cell A is -0.35 MPa, and its pressure potential (ψP) is +0.15 MPa. The solute potential (ψS) of cell B is -0.30 MPa, and its pressure potential (ψP) is +0.05 MPa. In which direction will net water movement occur? A) Neither; cells A and B are in equilibrium with each other. B) from cell A to cell B C) from cell B to cell A
b
What causes rigor mortis?A. exhaustion of Ca2+ from the sarcoplasmic reticulumB. lack of ATP in dead tissueC. lack of acetylcholine (ACh) in dead tissueD. cessation of action potentials after death
b
What is an essential part of alternation of generations in plants? A) meiosis to produce gametes B) mitosis to produce gametes C) fertilization to produce spores D) fertilization to produce gametes
b
What is true about plant meristematic cells? A) They are distributed evenly in all tissues throughout the plant. B) They are undifferentiated cells that produce new cells. C) They increase the surface area of dermal tissue by developing root hairs. D) They subdivide into three distinct cell types named parenchyma, ground meristem, and procambium.
b
What would be the effect on muscle contraction if troponin were experimentally altered to no longer interact with tropomyosin, so the complex could no longer bind to actin? A. Muscle contraction could no longer occur. B. Muscles could not relax after contraction. C. Muscle contraction would be weakened but would still occur as long as tropomyosin is functional .D. ATP could not be hydrolyzed by enzymes in the muscle.
b
When an action potential from a motor neuron arrives at the neuromuscular junction (NMJ), a series of events occurs that leads to muscle contraction. Which of the following events will occur last (i.e., after all of the others)? A. ACh release B. Conformational change in troponin C. action potential propagation down the T-tubules D. Depolarization of the muscle cell E. Release of Ca2+ from the sarcoplasmic reticulum
b
Which of these should decline in hybrid zones where reinforcement is occurring? A. Hybrid sterility. B. Gene flow between distinct gene pools. C. The genetic distinctness of two gene pools. D. Speciation
b
Which structure is common to both gymnosperms and angiosperms?A. Ovary B. Ovule C. Carpel D. Stigma
b
sympatric speciation differs from allopatric speciation because in sympatric speciation... a) two populations of the same species merge together to form a single population b) there are no physical barriers against interbreeding c) a population becomes more geographically isolated d) polyploidy must first arise.
b
water moves through the plant by each of the following methods except? a) from cell to cell across the PM b) through the casparian strip c) through the spaces between the cells d) from cell to cell through plasmodesmata
b
what is not a function of oligodendricytes/ schwann cells? a) supplying nutrients b) conducting nerve impulses c) supporting neurons during embryonic development d) consuming foreign particles
b
antibodies are made by...
b cells
natural selection that maintains two or more phenotypic forms in a population
balancing selection
allopatric speciation occurs because a population...
becomes geographically isolated and undergoes genetic change.
What field of study uses geographic distribution of extinct and living species to determine patterns of evolution?
biogeography
a group of individuals that can interbreed in nature and produce viable offspring would be considered to be a species according to what?
biological species concept
The first cavity formed during sea urchin development is the
blastocoel
the fluid-filled cavity of a blastula
blastocoel
embryonic disk that gives rise to the endoderm, mesoderm, ectoderm
blastoderm
The opening of the archenteron in the gastrula that develops into the mouth in protostomes and the anus in deuterostomes
blastopore
Genetic drift resulting from the reduction of a population, typically by a natural disaster, such that the surviving population is no longer genetically representative of the original population.
bottleneck effect
A rabbit taken from a meadow near sea level and moved to a meadow high on a mountainside would have some trouble breathing. Why? A) The percentage of oxygen in the air at high elevations is lower than at sea level. B) The percentage of oxygen in the air at high elevations is higher than at sea level. C) The partial pressure of oxygen in the air at high elevations is lower than at sea level. D) The partial pressure of oxygen in the air at high elevations is higher than at sea level.
c
According to the concept of punctuated equilibrium, the "sudden" appearance of a new species in the fossil record means that A. speciation occurred in one generation. B. the species is now extinct. C. speciation occurred rapidly in geologic time. D. the species occurred instantaneously.
c
As compared to the circulatory system of most fishes, the circulatory system of adult amphibians has the advantage of A. a four-chambered heart. B. heart metamorphosis. C. a partial separation between pulmonary and systemic circulation. D. a pocket of the gut that serves as an air bladder.
c
How have fruits contributed to the success of angiosperms? A. By producing triploid cells via double fertilization. B. By nourishing the plants that make them. C. By facilitating dispersal of seeds. D. By producing sperm and eggs inside a protective coat.
c
Most Swiss starlings produce four to five eggs in each clutch. Starlings producing fewer, or more, than this have reduced fitness. Which of the following terms best describes this situation? A. Disruptive selection B. Directional selection C. Stabilizing selection D. Artificial selection
c
Most of the chemosensory neurons arising in the nasal cavity have axonal projections that terminate in the A. occipital lobe. B. gustatory complex. C. olfactory bulb. D. pituitary gland.
c
Plants produce more seeds when they reproduce asexually than sexually. Yet most plants reproduce sexually in nature. What is the probable explanation for the prevalence of sexual reproduction? A) Sexual reproduction is more energy efficient than asexual reproduction. B) Sexual reproduction ensures genetic continuity from parents to offspring. C) Sexual reproduction mixes up alleles contributing to variation in a species. D) Sexual reproduction is not dependent on other agents of pollination.
c
Select the correct statement describing sympatric speciation. A. Sympatric speciation is always initiated by geographic isolation of two populations. B. Sympatric speciation has never been observed in nature. C. Sympatric speciation can occur in a single generation.
c
Suppose you traveled back in time and located the first animals to have developed feathers. You found that these animals were tree-dwelling ectotherms, able to run quickly but unable to fly. You also noticed that females of the species had no feathers at all, while males had bright blue feathers covering their tails. Which hypothesis of feather evolution would these data most support? A) Feathers initially evolved to aid in flight. B) Feathers initially evolved as a form of insulation. C) Feathers initially evolved for use in courtship displays, a form of sexual selection. D) Feathers initially evolved to help tree-dwelling species glide from tree to tree.
c
The "selectivity" of a particular ion channel refers to its A. permitting passage by negative but not positive ions. B. permitting passage by positive but not negative ions. C. permitting passage only to a specific ion. D. ability to change its size depending on the ion needing transport.
c
The best classification system is that which most closely A. unites organisms that possess similar morphologies. B. conforms to traditional, Linnaean taxonomic practices. C. reflects evolutionary history. D. reflects the basics separation of prokaryotes from eukaryotes.
c
The function of antibodies is to A. inject toxins into living pathogens. B. secrete cytokines that attract macrophages to infection sites. C. mark pathogenic cells for destruction. D. release perforins to disrupt infected cells.
c
The only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart are the a) amphibians. B) birds. C) fishes. D) reptiles.
c
The seed coat's most important function is to provide A. a nutrient supply for the embryo. B. the means for dispersal. C. protection for the embryo. D. a nonstressful environment for the megasporangium.
c
The study of factors that determine the size and structure of populations through time is called _____. A. population ecology B. immigration and emigration C. demography D. populations E. logistic growth
c
What is nottrue about the carpel of a flower? A) The stigma receives the pollen. B) The style provides the pathway for the growth of the pollen tube. C) Meiosis of the megaspore forms the pollen. D) The ovary encloses one or more ovules.
c
When you are jogging, your muscles are using more oxygen and releasing more carbon dioxide into the blood than when you are at home on the couch. Which of the following would occur during your jog? A) Blood pH would increase by at least 1 pH unit. B) The concentration of bicarbonate ions (HCO3-) in the blood would decrease. C) The medullary respiratory center would increase the rate of breathing. D) All of the above answers apply.
c
Which of the following is in the correct order regarding hierarchical classification (Linnaean classification)? A. Genus, family, phylum, order, class, kingdom, species, domain. B. Family, phylum, order, class, kingdom, species, domain, genus. C. Domain, kingdom, phylum, class, order, family, genus, species. D. Kingdom, domain, species, genus, family, phylum, order, class.
c
Which of the following properties of HIV makes it difficult to trace the source of the virus from one person to the next? A. The transmission of the virus involves very few (often just one) viral particles. B. HIV evolves very slowly within the host. C. The host can have a genetically diverse population of viruses. D. Molecular phylogenies of viruses cannot be constructed.
c
Which of these structure-function pairs is incorrect? A) stomata-regulate gas exchange B) trichomes-repel herbivores C) cuticle-layer of cells where light reactions occur D) guard cells-control stomatal pore size
c
alteration of generations means... a) one phase of the life cycle is photosynthetic and the other is heterotrophic b) one phase of the life cycle is unicellular and the other it is multicellular c) one phase of the life cycle is diploid and the other is haploid
c
the angiosperm carpel serves to a) attract pollinators b) produces sugars via photosynthesis c) protects the ovules and seeds d) prevents cross pollination
c
the opening of the stomata is thought to involve... a) a decrease in solute concentration of the stoma b) active transport of water out of the guard cells c) an increase in the solute concentration of the guard cells d) decreased turgor pressure in guard cells
c
which scenario best describes the process of natural selection? a) a population of foxes increases as more prey becomes available. b) a plant loses its leaves in a drought c) a population of mosquitoes develops resistance to pesticide d) a bear learns to find food at a garbage dump
c
A water-impermeable ring of wax in the endodermal cells of plants that blocks the passive flow of water and solutes into the stele by way of cell walls.
casparian strip
Telencephalon is the...
cerebral hemispheres
Outermost layer of the two membranes surrounding the embryo; it forms the fetal part of the placenta
chorion
Attraction between molecules of the same substance
cohesion
type of ground tissue cell with a strong, flexible cell wall; helps support larger plants
collenchyma
the cleavage furrow formed after mitosis completely separates the daughter blastomeres (sea stars and frogs)
complete cleavage (holoblastic)
A mutation arises in an individual that decreases its fitness. This means that this individual's
contribution to the gene pool of the next generation will decrease
The transfer of heat by the movement of a fluid or gas
convection
Cacti in the deserts of southwestern North America and some euphorbs of the deserts of Africa, have barrel-shaped stems, short-lived leaves, and spines, yet these two types of plants are from different evolutionary lineages. This is an example of
convergent evolution
Process by which unrelated organisms independently evolve similarities when adapting to similar environments
convergent evolution
which of the following can be a homoplastic trait? a) divergent evolution b) convergent evolution c) homology d) shared ancestry
convergent evolution
stress hormone released by the adrenal cortex
cortisol
3. Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from very similar embryonic tissues. How do biologists interpret these similarities? A. By proposing that humans, bats, and dolphins share a common ancestor. B. By the principle of convergent evolution. C. By identifying the bones as being homologous structures. D. Two of the statements above are correct.
d
4. Many crustaceans (e.g., lobsters, shrimp, and crayfish) use their tails to swim, but crabs have reduced tails that curl under their shells and are not used in swimming. This is an example of _____. A. an adaptation B. a homologous structure C. natural selection D. a vestigial trait
d
6. Although each of the following has a better chance of influencing gene frequencies in small populations than in large populations, which one most consistently requires a small population as a precondition for its occurrence? A. Mutation B. Natural selection C. Gene flow D. Genetic drift
d
74. After the depolarization phase of an action potential, the resting potential is restored by A. a brief inhibition of the sodium-potassium pump. B. the opening of more voltage-gated sodium channels. C. a decrease in the membrane's permeability to potassium and chloride ions. D. the opening of voltage-gated potassium channels and the closing of sodium channels.
d
All of the following are common to both charophytes and vascular land plants except A. chlorophyll a B. cellulose C. sporopollenin D. lignin
d
Among the last line of defenses against prolonged exposure to an extracellular pathogen is a) histamine released by basophil cells b) lysis by natural killer cells c) phagocytosis d) antibody production by plasma cells
d
An "internal reservoir" ofoxygen in rested muscle is found in oxygen molecules bound to A) hemoglobin. B) bicarbonate ions. C) actin and myosin. D) myoglobin.
d
Antigens are A. proteins found in the blood that cause foreign blood cells to clump. B. proteins released during an inflammatory response. C. proteins embedded in B cell membranes. D. foreign molecules that trigger the generation of antibodies.
d
As an undergraduate research assistant in the lab of the famous Dr. S. Nameerf, your duties involve measuring water potential in experimental soil-plant-atmosphere systems. Assume you make a series of measurements in a system under normal daylight conditions, with stomata open and photosynthesis occurring. Which of the following correctly depicts the trend your measurement data should follow if the cohesion-tension mechanism is operating? A) ψsoil < ψroots = ψleaves < ψatmosphere B) ψatmosphere < ψleaves = ψroots < ψsoil C) ψsoil < ψroots < ψleaves < ψatmosphere D) ψatmosphere < ψleaves < ψroots < ψsoil
d
During most daily activities, the human respiration rate is most closely linked to the blood levels of A) nitric acid. B) nitrogen. C) oxygen. D) carbon dioxide.
d
Hardy-Weinberg equilibrium must occur in populations wherein A. an allele remains fixed. B. natural selection is not operating. C. no genetic variation exists. (no gene flow) D. All three of the responses above are correct.
d
In a simple synapse, neurotransmitter chemicals are received by A. cell bodies. B. axon hillocks. C. the presynaptic membrane. D. the dendritic membrane.
d
In animals, nitrogenous wastes are produced mostly from the catabolism of A. starch and cellulose. B. fatty acids and glycerol C. triglycerides and steroids .D. proteins and nucleic acids.
d
Materials are returned to the blood from the filtrate by which of the following processes? A. Filtration B. Secretion C. Excretion D. Reabsorption
d
Natural selection is based on all of the following except A) genetic variation exists within populations. B) the best-adapted individuals tend to leave the most offspring. C) populations tend to produce more individuals than the environment can support. D)individuals adapt to their environments and, thereby, evolve.
d
One feature that amphibians and humans have in common is A) the number of heart chambers. B) thetype of gas exchange tissues. C) a complete separation of circuits for circulation. D) the number of circuits for circulation.
d
Rocky Mountain juniper (Juniperus scopulorum) and one-seeded juniper (J. monosperma) have overlapping ranges. If pollen grains (which contain sperm cells) from one species are unable to germinate and make pollen tubes on female ovules (which contain egg cells) of the other species, then which of these terms is applicable? A. Reduced hybrid viability B. Behavioral isolation C. Hybrid breakdown D. Mechanical isolation
d
Self-propagation and refractory periods are typical of A. graded hyperpolarizations. B. threshold potentials. C. resting potentials. D. action potentials.
d
Sperm-egg interactions are species-specific in sea urchins, but not in mammals. What might be one reason for this difference? A) Other kinds of signals serve similar functions in mammals. B) Sperm-egg recognition relies on egg cytoplasmic components in mammals. C) Sperm have evolved to become more selective in mammals. D) Sea urchin fertilization occurs in open ocean.
d
Sponges, cnidarians, and flatworms lack a specialized gas exchange surface because A) they live without need for oxygen. B) they do not produce carbon dioxide. C) countercurrent exchange mechanisms cannot function well in their living conditions. D) nearly all of their cells are in direct contact with the external environment.
d
The MHC is important in a T cell's ability to A. recognize specific parasitic pathogens. B. identify specific bacterial pathogens. C. identify specific viruses. D. distinguish self from nonself.
d
The rise of methicillin-resistant Staphylococcus aureus (MRSA) can be considered to be an example of artificial selection because A. S. aureus is cultivated by humans to replenish the soil with nutrients. B. humans are becoming resistant to bacteria by taking methicillin. C. humans purposefully raise MRSA in large fermenters in an attempt to make the bacteria ever-more resistant. D. humans synthesize methicillin and create environments in which bacteria frequently come into contact with methicillin.
d
The segmented characteristic of human embryonic development is evident from the bricklike structures called _______ that form along the notochord. A. neural tubes B. mesoderm C. ectoderm D. somites
d
What do all deuterostomes have in common? A) Adults are bilaterally symmetrical. B) All have a spinal column. C) All have specialized head and tail regions. D) The pore formed during gastrulation becomes the anus.
d
What happens during gastrulation? A) The neural tube forms. B) The blastula forms. C) The somites form. D) The three embryonic tissue germ layers form.
d
Which of the following concepts adds a dimension of time to a phylogenetic analysis? A. Maximum likelihood B. Parsimony C. Cladistics D. A molecular clock
d
Which of the following statements best summarizes evolution as it is viewed today? A. It represents the result of selection for acquired characteristics. B. It is the descent of humans from the present-day great apes. C. It is synonymous with the process of gene flow. D. It is the differential survival and reproduction of the most-fit phenotypes.
d
Which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools? A. Morphological B. Ecological C. Phylogenetic D. Biological
d
Which of these actions describes secondary growth? A) growth in height B) development of fruit C) development of leaves and flowers D) development of wood and bark
d
the activation of a rhodopsin molecule sets off a chain reaction that leads to.... a) formation of an activated phosphate molecule b) opening of a sodium channel c) activation of a large number of transducing molecules d) closing a large number of sodium channels
d
which of the following is unique to mammals? a) flagellated gametes b) heterotrophy c) cells that have mitochondria d) nervous conduction
d
Increased ADH secretion is likely after a) eating a small sugary snack b) ingesting alchohol c) blood pressure is abnormally high d) sweating-induced dehydration increases plasma osmolarity
d; sweating-induced dehydration increases plasma osmolarity
Ciliated gills in clams, sharks continuously swimming with their mouths partly open, countercurrent flow of blood and water in fish gills, and the use of air sacs to effect unidirectional flow of air through bird lungs are all adaptations that optimize what factor in the formula for Fick's Law of diffusion?
delta P
Fick's Law Variables
delta p
characteristics between the branch points of a cladogram that are shared by all organisms above the branch point and are not present in any below are called ____ characteristics.
derived
term used to refer to a cell that contains two sets of homologous chromosomes
dilpoid
occurs when natural selection favors one of the extreme variations of a trait
directional selection
when two or more species sharing a common ancestor become more different over time
divergent evolution
imagine that a paleontologist finds a fragment of a fossilized vertebrate that indicates the animal had a four-chambered heart. this animal could be a(n)
eagle
An animal whose body does not produce much internal heat
ectotherm
the humans arterial blood pH is tightly maintained around 7.4 by buffering agents that bind to hydrogen ions to stop any change in pH. if an acid-base imbalance overcomes the buffer system, the body changes the ventilation rate. changing the ventilation rate changes the concentration of CO2 in the blood, which alters the pH of the blood. in this case, the muscles that control ventilation rate are acting as the:
effector
In angiosperms, a nutrient-rich tissue formed by the union of a sperm with two polar nuclei during double fertilization. Provides nourishment to the developing embryo in angiosperm seeds.
endosperm
The rate of gas transfer (V gas) is proportional to the tissue area, the diffusion coefficient of the gas, and the difference in the partial pressure of the gas on the two sides of the tissue, and inversely proportional to the thickness.
ficks law of diffusion
a male silkworm locates a female at a distance by...
flying toward a chemical signal
more complex functions in the ___.
forebrain
Genetic drift that occurs when a few individuals become isolated from a larger population and form a new population whose gene pool composition is not reflective of that of the original population
founder effect .
A prezygotic reproductive barrier where the sperm of one species may not be able to fertilize the eggs of another species
gametic isolation
Changes in both cell shape and cell position occur extensively during (3)
gastrulation, organogenesis, or cleavage
in a small population, both ____ and ____ would violate the conditions of the hardy-weinburg equilibrium.
gene flow; genetic drift
what mechanism leads to changes in allele frequencies due to random chance?
genetic drift
blood enters a nephron's vascular component and is filtered by the way of the...
glomerulus
according to the concept of ___m species evolve continuously over long spans of time.
gradualism
-tissue found between the vascular and dermal tissue
ground tissue
Parenchyma, collenchyma, and sclerenchyma are all types of cells derived from
ground tissue
A plant that produces seeds that are exposed rather than seeds enclosed in fruits
gymnosperm
(genetics) an organism or cell having only one complete set of chromosomes
haploid
allow their body temperature to rise or fall depending on environmental conditions allow their body temperature to rise or fall depending on environmental conditions
heterotherms
autonomic functions in ___.
hindbrain
What pattern of cleavage is characteristic of mammals?
holoblastic cleavage with eggs containing very little yolk, but with the inner cell mass concentrated at one pole
divergent evolution creates ____ structures
homologous
Similarity in characteristics resulting from a shared ancestry.
homology
traits that are similar for some reason other than inheritance from a common ancestor
homoplastic traits
If goats are crossed with sheep, embryos will form but cease development and spontaneously abort. This is an example of
hybrid inviability
A term describing organisms with body fluids with a lower concentration of water and higher solute concentration than the external environment
hyperosmotic
dendrtic cells
immune cells
eggs with lots of yolk; cleavage does not divide entire egg
incomplete cleavage
in organisms such as the chick, in which the egg has extensive yolk, the egg shows ______.
incomplete cleavage
long term potentiation is
increased sensitivity to an electrical stimulus
Norephinephrine ____ the heart rate, whereas ACH ____ the heart rate.
increases; decreases
which of these is not a method used by ectotherms to affect body temperature?
increasing metabolic rate
Even in the absence of sperm, metabolic activity in an egg can be artificially activated by
injections of calcium into the cytosol
acidity in human sweat is an example of ____ immunity.
innate
Immunity that is present before exposure and effective from birth. Responds to a broad range of pathogens
innate immunity.
which of the following hormones exerts its action by interacting with a receptor at the cell surface?
insulin
solutions with the same concentrations of solute particles
isosmotic
The body fluids of an osmoconformer would be ________ with its ________ environment.
isosmotic; salt walter
An excretory system that is partly based on the filtration of fluid under high hydrostatic pressure is the...
kidneys of vertebrates
An increase in plant diameter results from cell division in which type of meristem?
lateral meristem
A meristem that thickens the roots and shoots of woody plants.
lateral meristems
another name for white blood cells
leukocytes
Found within the lymph nodes, they are phagocytes that destroy bacteria, cancer cells, and other foreign matter in the lymphatic stream.
macrophages
Processing of filtrate in the proximal and distal tubules does what?
maintains homeostasis of pH in body fluids
______ is an excretory system that actively transports uric acid and ions into blind tubules found in insects and most terrestrial arthopods.
malphagian tubes
Morphological differences prevent fertilization.
mechanical isolation
during spring time in maine, male moose often enter a cow pasture and begin calling to the female cows. the male moose might even try to mount the female but the males genitalia does not fit inside the female. this is an example of...
mechanical isolation
incomplete division of the egg, occurs in species with yolk-rich eggs, such as reptiles and birds
meroblastic cleavage
In annelid worms, a type of excretory tubule with internal openings that collect body fluids and external openings that excrete waste from the body.
metanephridia
Region between the hindbrain and the forebrain; it is important for hearing and sight.
midbrain
ALL descendants came from one common ancestor
monophyletic
Engulfing-phagocytic cells of innate immunity include all of the following except a) macrophages b) dendritic cells c) natural killer cells d) neutrophils
natural killer cells
A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.
natural selection
rare phenotypes are favored by selection
negative frequency dependent selection
In a species of salamander, there are two forms, red and yellow. As the yellow form becomes less common due to predation and the red form more common, the yellow form becomes less likely to be eaten and more likely to survive and reproduce. The yellow form then becomes more common and roles of red and yellow forms reverse. This is an example of
negative frequency-dependent selection
peripheral nerves cells are derived from...
neural crest cells
what developmental event was key to the evolution of chordates, by forming the notochord and dorsal nerve cord?
neurolation
2 primary cell types in nervous tissue
neurons and neuroglia
____ are marine organisms that maintain an internal environment that is isosmotic to their external environment. This means that the osmotic pressure, or osmolarity, of the organism's cells is equal to the osmotic pressure of their surrounding environment
osmoconformers
the islets of langerhans located in the ____ secrete both insulin and glucagen.
pancreas
Some intercellular regulatory molecules that exert only very local effects are called ________ regulators.
paracrine
Pertaining to a group of taxa that consists of a common ancestor and some, but not all, of its descendants.
paraphyletic
Fundamental tissue composed of thin-walled living cells that function in photosynthesis and storage.
parenchyma
the vascular tissue in plants that conducts sugars and other metabolic products downward from the leaves.
phloem
which of the following is not a leukocyte? a) neutrophil b) dendritic cell c) platelet d) mast cell
platelet
An organism whose body temperature changes with its surrounding environment
poikilotherm
which of the following can be found in gymnosperms?
pollen
Thick-skinned rhinoceroses and elephants were once classified together as pachyderms (meaning "thick skin"). They actually descended from different ancestors that in turn evolved from a thin skinned common ancestor that was not included in the pachyderms. Pachyderms were therefore, as a taxon, a) a supergroup b) monophyletic c) polyphyletic d) paraphyletic
polyphyletic
includes taxa with different ancestors
polyphyletic
In _____, the fitness of a phenotype or genotype increases as it becomes more common.
positive frequency dependent selection
In a simple synapse, neurotransmitter chemicals are released by
presynaptic membranes
in amphibian eggs, cells migrate to the interior of the embryo through the blastopore. in mammalian embryos with small amounts of yolk, this movement occurs at the...
primitive groove
an excretory system, such as the flame bulb system of flatworms, consisting of a network of tubules lacking internal openings
protonephridia
Covered with root hairs, which increase the surface area for absorption
root epidermis
type of ground-tissue cell with an extremely thick, rigid cell wall that makes ground tissue tough and strong
sclerenchyma
the generation of action potentials in sensory neurons initiated by changes in pressure is an example of
sensory transduction
A leaflike structure that encloses the bud of a flower.
sepal
what is the correct order of floral organs from the outside to the inside of a complete flower?
sepals-petals-stamens-carpals
the humans arterial blood pH is tightly maintained around 7.4 by buffering agents that bind to hydrogen ions to stop any change in pH. if an acid-base imbalance overcomes the buffer system, the body changes the ventilation rate. changing the ventilation rate changes the concentration of CO2 in the blood, which alters the pH of the blood. in this case, the pH of 7.4 is the:
set point
A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates.
sexual selection
When several EPSPs arrive at the axon hillock from different dendritic locations, depolarizing the postsynaptic cell to threshold for an action potential, this is an example of
spatial summation
in ____ selection, individuals intermediate in a phenotypic distribution have greater reproductive success.
stabilizing selection
Male part of the flower; made up of an anther and a filament.
stamen
in which plant cell or tissue would the pressure component of water potential most often be negative?
stem xylem
The tip of the female reproductive structure of a flower where the pollen lands
stigma
The formation of new species in populations that live in the same geographic area
sympatric speciation
trait shared with ancestor
symplesiomorphy
shared derived trait
synapomorphy
The antigen receptor on T cells; a membrane-bound molecule consisting of one α chain and one β chain linked by a disulfide bridge and containing one antigen-binding site.
t cell receptor
which of the following does not arise from a myeloid progenitor cell?
t lymphocyte
form of reproductive isolation in which two populations reproduce at different times
temporal isolation
the northern leopard frog and southern leopard frog are morphologically similar, but their mating calls sound very different. based on this, what is the best explanation for why these frogs are considered separate species?
they have undergone behavioral isolation that prevents them from interbreeding
Also called thryoid hormone, thyroxine is produced and secreted by follicle cells in the thyroid gland. it targets all cells in the body and increases overall body metabolism.
thyroxine
which hormone sets the body's basic metabolic rate?
thyroxine
in plants, there is transport through structures called ____.
tracheids
in humans, the amnion forms the _____.
trophoblast
outer cells of the blastocyst that secrete enzymes that allow implantation
trophoblast
A protein of muscle that forms a complex with troponin regulating the interaction of actin and myosin in muscular contraction
tropomyosin
A protein of muscle that together with tropomyosin forms a regulatory protein complex controlling the interaction of actin and myosin and that when combined with calcium ions permits muscular contraction
troponin
a newborn baby dies soon after birth because her diaphragm and rib cage muscles failed to contract and she was unable to breathe on her own. examination of the baby's DNA revealed she had a genetic mutation in a gene that encoded a calcium-binding protein. which protein was most likely defective in the baby?
troponin
The _____ and ______ are lateral meristems.
vascular cambium, cork cambium
The activation of helper T cells is likely.. a) when b cells respond to t-independent antigens b) when an antigen body is displayed by a dendritic cell c) when natural killer cells come in contact with a tumor cell d) when a cytotoxic t cell releases cytokines
when an antigen is displayed by a dendritic cell
vascular tissue that carries water upward from the roots to every part of a plant
xylem