What is true of both mitochondria and chloroplasts?
They include compartments where hydrogen ions are concentrated.
The tertiary structure and function of the polypeptide is principally determined by...
interactions between amino acids present in the polypeptide.
In a species that has 5 different alleles for a gene at a particular locus, how many different alleles may be present in the somatic cells of one diploid individual?
If red blood cells cultured in an isotonic medium are placed in distilled water, they will most likely...
swell and lyse
The best evidence that the giant panda is more closely related to bears than is the raccoonlike lesser panda involves...
DNA sequence comparisons
Which of the following structures contains highly oxygenated blood?
Metabolism of which of the following molecules results in the greatest net usable energy per gram?
Cells that make up salivary glands would be expected to contain a relatively large amount of...
rough endoplasmic reticulum
Which of the following characteristics distinguishes prokaryotic organisms from eukaryotic organisms?
Prokaryotes are structurally less complex than eukaryotes are.
An important role of soil microbes in biological systems is the...
recycling of matter
Which of the following diseases is caused by the lack of a functional gene responsible for a specific enzyme?
How many different genotypes are possible from the cross shown above?
Which of the following sequences best represents the life cycle of a typical angiosperm?
sporophyte, meiosis, gametophyte, gametes, fertilization, zygote, sporophyte
Birds associating the bright colors of certain butterflies with an unpleasant taste is an example of...
trial and error learning
Which of the following best describes allosteric inhibition of an enzyme?
the inhibitor binds to the enzyme but not at its active site
Which of the following organelles is correctly matched with its function?
The occurrence of a particular genetic condition in a family is shown in the pedigree above. Which of the following is the most likely inheritance pattern for the individuals with the condition> Squares represent males, circles represent females, and shaded symbols represent individuals who exhibit the condition.
Rates of adaptive radiation typically are at their highest in which of the following situations?
When new niches become available
Which of the following led to the increased function of the invertebrate nervous system?
Cephalization of the major sensory organs and the cerebrum
Which of the following is the most direct result of the heating up of pond water during the summer?
the water's ability to hold oxygen decreases.
A protein is synthesized in the cytoplasm and transported to the plasma membrane. Which of the following summarizes the protein's pathway in the cell?
Rough endoplasmic reticulum, golgi complex, vesicle, plasma membrane
In most dicot seeds, which of the following structures is responsible for the storage of carbohydrates?
In mammals, which of the following substances is produced in a muscle that operates anaerobically?
What immune system cell is most severely depleted by HIV/AIDS?
helper T cells
The primary producers of the deep sea communities associated with hot water vents are...
A scientist studying the oxygen concentration in sealed chambers containing cultured plant cells finds that when the chambers are illuminated, the concentration of oxygen decreases. Why does the oxygen concentration decrease when the chamber is kept in the dark?
Plant cell mitochondria consume oxygen by aerobic respiration.
The unequal division of the cytoplasm among frog embryo cells during early cleavage, as shown in the diagram, results from...
uneven distribution of yolk
Production of ATP occurs in al of the following processes EXCEPT
light - independent reactions of photosynthesis
Which of the following statements most correctly represents the organization of living systems from the smallest to largest?
Atoms, molecules, cells, organisms, ecosystems
The functional similarity of the mandibles (hinged jaws) of insects and those of mammals is an example of...
Which of the following pairs of plants are most closely related?
Kidney bean and scarlet runner bean
Milk kept past the expiration date often spoils, tastes sour, and develops stringy curds. This can be explained by what?
Bacteria produce lactic acid, which lowers the pH and denatures the milk proteins.
A research study sampled populations of field mice annually over the course of 50 years. The population was categorized by coat color. What type of selection is represented?
What occurs in both fermentation and aerobic cellular respiration?
ATP is synthesized from ADP and inorganic phosphate.
What best summarizes the theory of punctuated equilibrium?
Most taxa experience relatively short periods during which they undergo rapid change, followed by relatively long periods during which they undergo relatively little change.
What organism possesses both a system of blood vessels and a digestive tract in which food travels in only one direction?
An intake system is compromised of a series of tubes.
What occurs in the immediate fight or flight response to danger or fear?
An increase in glucose catabolism
During the fall, a chipmunk experiences a sustained period of cold weather. The chipmunk's thyroid gland responds by secreting a greater quantity of thyroxin. Which of the following represents the most accurate pathway from the central nervous system to the target cells?
CNS, hypothalamus, anterior pituitary, thyroid, thyroxin, target cells
What ion is significantly involved in the opening and closing of the stomata?
What best explains why many different species can live together within an ecosystem with limited resources?
each species occupies a different niche
What occurs in response to a rise in the blood sugar level?
Beta cells in the pancreas release insulin.
In evolutionary terms, what organism is the most successful?
The one that leaves the greatest number of offspring that survive to reproduce.
What statement about the process of excretion in animals is correct?
Animals with closed circulatory systems usually have capillary beds associated with their excretory organs.
What is true of a specialized companion cell of the phloem that is connected to the palisade mesophyll cell by plasmodesmata?
Materials synthesized in photosynthesis could be sent from the mesophyll cell to the companion cell.
The flow of which of the following into the mitochondrial matrix provides the chemiosmotic energy for the synthesis of ATP?
Fire has what effect on the community?
It recycles dead plant material, thus nutrients become available.
As plants evolved from simple to more complex forms, which of the following occurred?
The sporophyte generation became more dominant than the gametophyte generation.
If a population is at Hardy - Weinberg equilibrium, which of the following can be predicted for the recessive alleles in the population?
They will be maintained at the same frequency.
A large assemblage of land snails is subdivided into two populations ( A and B) by a river that effectively isolates the two populations for an indefinitely long period. From an evolutionary standpoint, what is LEAST likely to occur in the two populations?
Populations A may undergo instantaneous speciation by the doubling of its chromosome numbers (polyploidy).
What is TRUE of C4 plants such as corn?
The calvin cycle is confined to the bundle sheath cells.
What causes the rapid change of membrane polarity during an action potential?
Diffusion of positively charged ions across the cell membrane.
Structure that stores lipid - emulsifying salts
Structure where pepsin hydrolyses proteins
Structure that produces most of the hydrolytic enzymes that are active in the small intestine.
Structure where glycogen typically occurs in large quantities as a storage product.
Molecule contains a porphyrin ring with a central magnesium atom.
Causes plants shoots to bend toward light by stimulating cell elongation.
Regulates flowering in plants that are sensitive to the length of the photoperiod.
Molecule that can absorb photons of light and release electrons to the primary electron acceptor.
Protein synthesis termination triplet
Site of protein synthesis
Base sequence on messenger RNA that aids its transport across the nuclear envelope
extra - chromosomal circular DNA
triplet on tRNA
typical of prokaryotic cells after fission
eukaryotic cells at prophase of mitosis
unpaired replicated linear chromosomes
eukaryotic cells at metaphase 1
paired replicated linear chromosomes
plasmid exchanged by conjugating bacteria
extra - chromosomal circular DNA
After 10 days, the distilled water culture dish has approximately how many duckweed plants?
In pond water, the duckweed population grows at an average rate of...
1 plant per 3 days
Neurotransmitters characterized as inhibitory would NOT be expected to
open Na+ channels
Neurotransmitters are released from presynaptic axon terminals into the synaptic cleft by
A human red blood cell in an artery of the left arm is on its way to deliver O2 to a cell in the thumb. From this point in the artery, how many capillary beds must this red blood cell pass through before it returns to the left ventricle of the heart?
If a physician hears two "lub" sounds instead of one, then what is true?
the atrioventricular valves are not closing at the same time
The control over milk production, water balance, and labor in childbirth is mediated by the
The spaces that separate adjacent Schwann cells
If a molecule of CO2 is released into the blood in your left toe out of your nose, it must pass all structures EXCEPT
leads to, through, and from the lungs
Activity associated with parasympathetic division of the nervous system
coordinates muscle actions
Only endocrine gland whose secretary function is under direct control of sympathetic nerves
What would be most affected if an accident caused trauma to the hypothalamus
regulation of body temperature
during stress ACTH stimulates the adrenal cortex, the neurons of the sympathetic nervous system stimulate the adrenal medulla
the adrenal gland
exhalation of air from the human lungs
volume of thoracic cavity decreases
stimulates and maintains metabolic processes
hormone that prepares and maintains the uterine lining for pregnancy
estrogen and progesterone
If the concentration of potassium in the cytoplasm of a nerve cell with a resting membrane potential of -70 mV were elevated above normal, the new resting potential would
-69mV or higher
what type of tissue is blood
organisms in which a circulating body fluid is distinct from the fluid that directly surrounds the body's cells are likely to have...
a closed circulatory system
hormones are distributed throughout the body by
What is associated with the evolution of the nervous system
air rushes into the lungs of humans during inhalation because
the rib muscles and diaphragm contract, increasing lung volume
controls the shape of the eye lens to allow focusing
the ciliary muscle
which system is involved with heat production
the hypothalamus controls the anterior pituitary by
the blood level of....is most important in controlling human respiration rate
the release of cyclic AMP as a second messenger is a response to
glycoprotein and peptide hormones
after an action potential, the resting potential is restored by
the opening of voltage sensitive potassium channels and closing of the sodium activation gates
part of the brain that controls basic responses necessary to maintain life processes
the following states of fertilization and early development
acrosomal reaction, plasma membrane, depolarization, cortical reaction, fusion of egg and sperm nuclei complete, onset of new DNA synthesis, first cell division
The changing of the vitelline membrane into a hard fertilization envelope that further resists the entry of other sperm.
The discharge of hydrolytic enzymes from the acrosome, a vesicle in the tip of a sperm, when the sperm approaches or contacts an egg.
most enzymatic hydrolysis of macromolecules in food occurs in the
both the eye and the respiratory tract are protected against infections by
secretion of lysozome onto their surface
what process of osmoregulation by the kidney is LEAST selective
these cells are involved in innate immunity, and a person lacking these might have a higher chance of getting a malignant tumor
natural killer cells
the filtrate removed from the blood by the kidneys might contain
salts, amino acids, glucose, and urea
breaks down globules of fat into tiny droplets
kidneys excrete little urine
the clonal selection theory implies that
antigens activate specific lymphocytes
in the inflammatory response, the absence of what prevents others from happening
release of histamine
once stimulated by antigens on the surface of macrophages, helper T cells may
stimulate B cells to divide and develop into plasma cells
after the initial immune response subsides, B cells that patrol body tissues for long periods of time which are responsible for initiating a second immune response
in the process of spore formation meiosis occurs in the life cycle of
heterosporus condition led to
gymnosperms, and angiosperms which bear pollen grains and seeds in female and male parts of plants
bryophytes differ in that
have independent gametophytes and dependent sporophytes
first phylum on evolutionary tree with 3 germ layers
organelles that capture the energy from sunlight and convert it into chemical energy in a process called photosynthesis
The reproductive organ of bryophytes, consisting of the male antheridium and female archegonium; a multichambered jacket of sterile cells in which gametes are formed.
fossil evidence of earliest living organisms
3.8 billion years ago
formation of polypeptide chains under abiotic conditions
supply structural units and enzymes to catalyze reactions
nematocysts are found only in
mollusks with the most complex nervous system
A ciliated (it propels itself via cilia) protist that lives in fresh water and eats other tiny organisms for food.
collection of spore chambers
red algae can live in deeper water because
first haploid cell in the life cycle of a plant
most unusual feature of echinoderms
water vascular system
rootlike absorbing filaments
seeds commonly provide for each of the following EXCEPT
choice of germination location
carnivorous plants have evolved mechanisms that trap and digest small animals. the products of this digestion are used to supplement the plant's supply of
what is the male gametophyte of a flowering plant
fruits develop from
a ring of cells that reproduce and increase the diameter of stems and roots
plants that grow on other plants but do not obtain nutrients from their hosts
the pigment responsible for photoperiodism
a plant's response to seasonal changes in length of night and day
the embryonic root
plants do not have a circulatory system like that of some animals. If a given water molecule did "circulate", it would require the activity of
xylem and phloem
the O2 needed by plants is ultimately derived from
process used by plants and other autotrophs to capture light energy and use it to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates such as sugars and starches
the division of the lateral meristem
increases the diameter of roots and stems
plant spores give rise directly to
in attempting to make a seed break dormancy one logically could treat it with
a growth hormone that causes a wide variety of effects. One role is to stimulate growth of stems by promoting cell division. Farmers use it to make fruit grow larger.
living cells that lack nuclei and ribosomes, they transport sugars and other organic nutrients
sieve tube members
what element is a component of both proteins and nucleic acids
which structure must pass through the micropyle for successful fertilization to occur in angiosperms
one sperm nucleus and two sperm nuclei (double fertilization)
one is most likely to see guttation in small plants when the
root pressure exceeds the transpiration pull
a botanist discovers a plant that lacks the ability to form starch grains in root cells, yet the roots still grow downward. This evidence refutes the long standing hypothesis that
falling statoliths trigger gravitropism
response of a plant to the force of gravity
a specialized plastid that contains dense starch grains and may play a role in detecting gravity
an example of a micronutrient
pressure flow hypothesis
the idea that carbohydrates produced in leaves through photosynthesis flow down phloem sieve tubes due to pressure from the leaf. the carbohydrates go down to the roots, where they are stored
in the pressure flow hypothesis of translocation, what causes the pressure
osmotic uptake of water by sieve tubes at the source
what do results of research on gravitropic responses of roots and stems show
the driving force that pushes the root tip through the soil is due primarily to
elongation of cells behind the root apical meristem
a durable polymer that covers exposed zygotes of charophyte algae and forms the walls of plant spores, preventing them from drying out.
the vascular bundle in the shape of a single central cylinder in a root
products of light reactions used by the calvin cycle
ATP and NADPH
reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugars
in the calvin cycle extra ATP comes from the
cyclic electron flow
cyclic electron flow
A route of electron flow during the light reactions of photosynthesis that involves only photosystem I and that produces ATP but not NADPH or oxygen.
a metabolic process that breaks down carbohydrates and sugars through a series of reactions to either pyruvic acid or lactic acid and release energy for the body in the form of ATP
in glycolysis, each molecule of glucose oxidized to pyruvate
two molecules of ATP are used and 4 are produced
2 carbon atoms are fed into the citric acid cycle as a result of
the oxidation of one molecule of pyruvate
citric acid cycle
in cellular respiration, series of chemical reactions that break down glucose and produce ATP; energizes electron carriers that pass the energized electrons on to the electron transport chain
metabolic pathway where glucose is degraded into CO2 and H2O
electron transport chain
a series of proteins in which the high-energy electrons from the Krebs cycle are used to convert ADP into ATP
the electron transport molecules of photophosphorylation are located in the
The process of generating ATP from ADP and phosphate by means of a proton-motive force generated by the thylakoid membrane of the chloroplast during the light reactions of photosynthesis.
the dense colorless framework of a chloroplast
function of both alcohol fermentation and lactic acid is to
oxidize NADH to NAD+
for the synthesis of glucose in the calvin cycle it must turn
only the calvin cycle requires
CO2 and ATP
only light reactions produce
acetyl CoA enters the citric acid cycle and is partially formed by the removal of
CO2 from pyruvate
when glucose is catabolized to pyruvate in glycolysis
most of the energy of glucose is retained in pyruvate
under the conditions of high light intensity, intense heat, and dryness
C4 plants would synthesize carbohydrates
the calvin cycle requires
CO2, ATP, RuBP
in the chloroplast
the cyclic electron flow produces ATP
rubisco participates in the calvin cycle and has an affinity for both
O2 and CO2
the reaction center chlorophyll of photosystem 1 is known as P700
best at absorbing light with wavelength 700nm
in the dark reactions of photosynthesis
PGAL is synthesized
produces the most ATP when glucose is completely oxidized to carbon dioxide and H2O
in a plant, ATP synthase complexes are located in the
thylakoid membrane and inner mitochondrial membrane
the PH in the interior of the thylakoid is
lower than that of the stroma
the ATP made during glycolysis is generated by
substrate level phosphorylation
the primary functions of the light reactions of photosynthesis are
to produce ATP and NADPH
Hershey and Chase
used bacteriophages and radioactive phosphorus in DNA and sulfur to determine what makes up genes
Griffith and Avery
Showed the transfer of genetic information between bacteria using mice
Meselson and Stahl
Used nitrogen isotopes to test the three models of DNA replication; found that semiconservative the most likely model.
synthesis of a new DNA double helix prior to mitosis and meiosis in eukaryotic cells and during prokaryotic fission in prokaryotic cells
the stage of the cell cycle during which the cell's nucleus divides into two new nuclei and one copy of the dna is distributed into each daughter cell
process by which the number of chromosomes per cell is cut in half through the separation of homologous chromosomes in a diploid cell
law of segregation
members of a pair of homologous chromosomes separate during the formation of gametes and are distributed to different gametes so that every gamete receives only one member of the pair
law of independent assortment
each member of a pair of homologous chromosomes separates independently of the members of other pairs so the results are random
situation in which both alleles of a gene contribute to the phenotype of the organism
the suppression of a gene by the effect of an unrelated gene
A single gene having multiple effects on an individuals phenotype
meiosis in which there is a failure of paired homologous chromosomes to separate
the most common congenital disease
an enzyme that untwists the double helix at the replication forks, separating the two parental strands and making them available as template strands
an organic compound, either RNA or DNA, whose molecules are made up of one or two chains of nucleotides and carry genetic information
monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base
the period of the cell cycle during which the nucleus is not undergoing division, typically occurring between mitotic or meiotic divisions