Create an account
An organism with chloroplasts in its cells is probably.
a. a heterotroph
b. an autotroph
c. an herbivore
d. a primary consumer
B: Organisms that have chloroplasts in their cells carry on photosynthesis and are therefore autotrophs. Autotrophs make their own food.
What property of water allows someone to fill a glass slightly above the rim without the water flowing over?
a. specific gravity
d. surface tension
D: Water molecules are polar. Due to the fact that O2 draws the electrons in the molecule toward itself.
The spaces between neurons are called?
d. cell gaps
A: An impulse travels down the axon of a neuron and reaches the terminus. There, chemicals are released in response, which travel across the synapse to the next neuron. Thus the impulse is transmitted to the next neuron.
Which Group of chemicals is not normally found in most living things?
d. nucleic acids
C: Carbohydrates, proteins, and nucleic acids (RNA and DNA) are all very important chemicals in living things.
The alimentary canal is associated with the?
a. spinal cord
b. digestive system
c. urinary tract
d. birth canal
B: The alimentary canal begins at the mouth and ends at the anus.
The numerous villi in the small intestine serve to?
a. secrete enzymes for digestion
b. absorb water from dissolved foods
c. secrete hydrochloric acid to dissolve food
d. provide greater surface for absorption
D: The villi are tiny projections in the small intestine that increase the total surface area of the intestine for absorption of digested nutrients.
As light passes obliquely from air to water, it is bent. This bending is called?
C: Refraction is the bending of light as it passes obliquely from one medium to another.
Which of the following organelles is not involved in protein synthesis?
c. rough endoplasmic reticulum
D: The nucleus contains DNA. The ribosomes, located on the rough endoplasmic reticulum, are the site for protein synthesis.
To be absorbed by cells, proteins must be changed to?
a. amino acids
c. fatty acids
A: Amino acids are the end products of protein digestion and are small enough to be absorbed.
A neuron that transmits impulses from the receptors to the spinal cord is called?
a. motor neuron
b. an associative neuron
c. an interneuron
d. a sensory neuron
D: A sensory neuron conveys a message from a sensory organ to the spinal cord, which transmits the message via a motor neuron to the effector muscle.
Which group of organisms help prevent the accumulation of organic wastes in nature?
C: Bacteria comprise the decomposer portion of the food chain.
As the eardrum is made to vibrate more rapidly, the sound is perceived as?
a. louder in intensity
b. softer in intensity
c. higher in pitch
d. lower in pitch
C: High-pitch sounds are heard when the receptor cells closer to the oval window are stimulated, and low-pitch sounds result from the stimulation of the cells that are farther down the cochlea.
In a field of pure white asters, a grower noticed a single blue aster. How could the grower test whether this change affected the gamete-producing cells of the plant?
a. self-pollinate the flower, and plant the resulting seeds
b. examine the blue petals under an electron microscope
c. preform a chemical analysis to find the nature of the blue pigment
d. preform vegetative propagation on a cutting of the plant
A: Remember that during a phase change from liquid to gas the temperature remains constant at 100C.
A human egg will develop into a female if it is fertilized by sperm containing?
a. an X chromosome
b. a Y chromosome
c. an XY chromosome
d. an XXY chromosome
A: A female has two X chromosomes, and a male has one X chromosome and one Y chromosome. For a human egg to develop into a female, it must be fertilized by a sperm containing an X chromosome.
In a food chain involving grass, grasshoppers, birds and mammals, the orginal source of energy is?
B: Sunlight is absorbed by the chlorophyll contained in plants. The absorbed energy fuels photosynthesis which produces glucose. In this food chain, grass is the producer.
Which of the following equations represents a neutralization reaction?
a. 2Na+MgCl2 > Mg+2NaCl
b. CaCO3+4C > 3CO+CaC2
c. 4NH3+5O2 > 6H2O+4NO
d. H2CO3+Ca(OH)2 > 2H2O+CaCO3
D: Equation d is a reaction between an acid (carbonic acid) and a base [(Ca(OH)2] to form water and a salt. It is the only neutralization reaction among the choices.
A reading on the Celsius scale is 5. On the Fahrenheit scale, the reading would be closet to?
C: the formula for converting temperature in Celsius to temperature in Fahrenheit is: T Fahrenheit = 9/5 x T Celsius + 32, therefore 5 degrees Celsius convert to 41 degrees Fahrenheit. 9/5 x 5 = 9
9 + 31 = 41F
Which of these formulas represents an alcohol?
D: An alcohol is usually characterized structurally by the presence of an OH group attached to a hydrocarbon.
If a car's rate of change of velocity is negative, the car is?
a. speeding up
b. maintaining a constant speed
c. slowing down
C: If a car's rate of change of velocity is negative, the car's acceleration is negative. this means that the car is decelerating (slowing down).
Consider the unbalanced equation __N2+__H2 > __NH3. What is the coefficient of ammonia in the balanced equation that has the smallest whole-number coefficient?
B: When balancing an equation, the number of atoms of each element must be the same on both sides of the equation: N2+3H2 > 2NH3
Which of these nitrogenous bases may be found in RNA, but not DNA?
A: Uracil is found in RNA but not DNA. Thymine is found in DNA but not in RNA. Guanine, cytosine and adenine are found in both.
A substance with a ph of 8 is a?
a. strong acid
b. weak acid
c. strong base
d. weak base
D: A substance with a ph between 8 and 14 is basic. The closer the substance gets to a ph of 14, the more basic it is.
Binary fission in paramecia and budding in yeast cells are examples of?
a. asexual reproduction only
b. sexual reproduction only
c. spontaneous generation and sexual reproduction
d. both sexual and asexual reproduction
A: Binary fission and budding are both examples of asexual reproduction, because cell division in both cases depends on mitosis.
Which of these substances forms an alkaline solution in water?
A: Magnesium hydroxide is the only base of the four choices. Thus in water, magnesium hydroxide releases hydroxide ions, forming a basic or alkaline solution.
Certain seaweeds accumulate iodine in a concentration as much as a million times greater than that of the surrounding ocean. How must this intake be accomplished?
c. active transport
d. passive transport
C: Since the concentrations are so much greater in seaweed than in the surrounding water, iodine must have to move against a concentration gradient.
Hydrogen can be prepared in the laboratory by combining Zn and HCl. In the resulting reaction, the metallic zinc (Zn).
a. is changed to another element
b. reacts with the water in the acid
c. replaces the combined hydrogen in the acid
d. serves as a catalyst
C: In the reaction, zinc replaces hydrogen and produces zinc chloride. Thus, hydrogen gas is released. Zn+2HCl > ZnCl2+H2 This is a single replacement reaction.
Which of the following organisms has a nutritive process most similar to that of animals?
b. oak tree
d. bread mold
D: Bread mold is a fungus. Fungi are unable to make their own food and are dependent on other life forms for nutrition. Fungi are heterotrophs. The other choices are all autotrophs.
The solubility of a solid in a liquid generally increases with?
a. an increase in temperature
b. an increase in pressure
c. a decrease in temperature
d. a decrease in pressure
A: Solubility of a solid in a liquid increases with increasing temperature but is unaffected by pressure. Pressure will only affect the solubility of a gas.
Which of these substances has the highest boiling point?
C: Water molecules are attracted to each other by hydrogen bonds. The others are not dipoles, so the attraction between the molecules is minimal.
In humans, if the diaphragm is pushed upward there is a decrease in chest volume. this decrease is followed by?
a. an increase in pressure in the chest cavity and inhalation
b. an increase n pressure in the chest cavity and exhalation
c. a decrees in pressure in the chest cavity and inhalation
d. a decrease in pressure in the chest cavity and exhalation
B: A decrease in volume results in an increase in pressure (Boyle's law) and thus exhalation.
Which of these biological processes includes the other three?
a. cell respiration
b Krebs cycle
c. electron transport chain
d. anaerobic splitting of glucose
A: Cellular respiration begins with the splitting of glucose. The products then enter the Kreb's cycle and then the electron transport chain.
A 5-year-old and her father each lifted identical chairs from the floor to the table top. Which person did the most work?
a. the father
b. the 5-year-old
c. they both did the same amount
d. not enough information is given
C: Work done is independent of who is doing it. Since both people move the object over the same distance and use the same force, they do the same amount of work.
An excess of which of these ions tends to make a solution acidic?
C: Hydronium ions, or H3O+, are essentially hydrogen ions combined with a nearby water molecule. In essence, acids are characterized by the presence of hydrogen or hydronium ions.
In the classification of two organisms, which of the following is the best evidence of a close relationship?
a. similar number and arrangement of bones
b. similar sequence of amino acids in their proteins
c. similar methods of sexual reproduction
d. similar methods of cell respiration
B: A similarity in amino acids suggests a similarity in the structure of the DNA and thus a close relationship between the organisms.
In Einstein's equation, E=mc2, which does C represent?
a. the quantum numbers of the atoms involved
b. the number of coulombs
c. the number of calories of heat
d. the speed of light
D: Einstein's equation, E=MC2, means energy = mass x (speed of light)2
the vaporization of solid dry ice to gaseous carbon dioxide by heating is an example of?
A: Sublimation is the direct vaporization of a solid by heating, without passing through a liquid state.
On top of a mountain, the boiling point of water is?
a. lower then at sea level, because the atmospheric pressure is higher on the mountain
b. lower then at sea level, because the atmospheric pressure is lower on the mountain
c. the same as at sea level, because the atmospheric pressure is the same in both locations
d. higher then at sea level, because the atmospheric pressure is lower on the mountains
B: The boiling point of a solution is the temperature at which the vapor pressure is equal to the pressure of the atmosphere.
Suppose cube A is 10cm along each edge and cube B is 5 cm along each edge. What is the relationship of the volume of cube A to that of Cube B?
a. cube A has two times the volume of cube B
b. cube A has four times the volume of cube B
c. cube A has six times the volume of cube B
d. cube A has eight time the volume of cube B
D: Cube A has a volume of 1,000 cm3, whereas cube B has a volume of 125 cm3. Cube A has 8 times the volume of cube B.
Which of these substances is a product of cellular respiration in animals?
A: Cellular respiration is an energy-yielding process that releases ATP (adenosine triphosphate) from organic molecules.
The tiny projections in the small intestine adapted for absorption are called?
B: Villi are tiny projections that are barely visible to the naked eye.
More energy is used in pushing a box up along an inclined plane to a height of 4 m then in liftting the box straight up to the same height. This is because?
a. more force is needed in pushing the box then in lifting it
b. work is done against friction in pushing the box along the plane
c. the box moves a greater distance when pushed along the plane then when lifted
d. it takes more time to push the box along the plane then to lift it
B: Whenever a box is along a surface, energy goes into counteracting friction. The amount of energy required is determined by the coefficient of friction.
A student wants to grow a bacterial culture. Which of these environments is best suited for growing most most kinds of bacteria?
a. a lighted window at 72 F
b. a refrigerator at 45 F
c. an incubator at 37 C
d. a freezer at 10 C
C: The optimal temperature at which bacteria grows is 37C.
A closed container of hydrogen gas is warmed from 20 C to 25 C. If the volume remains the same, what will happen to the pressure in the container?
a. it will remain the same
b. it will decrease
c. it will fluctuate
d. it will increase
D: According to Gay-Lussac's law of gases, as temperature increases at a constant volume, pressure increases proportionally. The pressure will increase.
Most of the work done by the human kidney occurs in the?
A: The functional unit of the kidney is the nephron. Urine is formed in the nephron by the processes of filtration, re-absorption, and secretion.
An equal-arm balance is balanced when 20 washers are on one side and 10 bolts are on the other. Four bolts are added to one side. How many washers must be added to the other side o maintain balance?
B: Since the equal-arm balance is balanced at a ration of 20 washers to 10 bolts, the weight of the bolts must be double that of the washers. Two washers are equivalent in mass to 1 bolt. Thus, 4 bolts are equivalent in mass to 8 washers. An increase of 4 bolts on one side will require 8 washers on the other side to maintain the balance.
Compounds with different molecular structures but but the same formula are called?
A: Isomers are compounds that have the same formula but different molecular structure. Isobars indicate the same pressure. Isotopes are atoms with the same atomic number but different mass numbers, and isotherms indicate the same temperature.
A student wanted to test the effects of different sugars on the growth of a certain mold. The sugars to be tested were glucose, fructose, and sucrose. One gram of each sugar was placed in a tube of 10 mL of water, and a bit of the mold was put in each of the three solutions. To add a control to the experiment, the student should also have?
a. made two
C: A control for this experiment would be to grow the mold in just water so that the results of the mold growth with sugar can be compared to the mold growth without sugar.
Vinegar is a common antidote for the ingestion of lye. What is the chemical process underlying this treatment?
D: Vinegar, an acid, neutralizes lye, a base.
Undisturbed layers of rock were examined. Mammal, fish, and bird fossils were found only in the upper layers. Fish were in layers beneath those, and neither fish, birds, nor mammals were in the deepest layers. This would tend to support the hypothesis that?
a. vertebrates always coexisted with invertebrates
b. fish were the first vertebrates to evolve
c. all vertebrates evolved at about the same time
d. birds evolved before fish
B: New layers of sediment cover old ones and provide a record of emergence of flora and fauna. the fish were the only fossils found in the layers beneath the upper layers, indicating that they evolved first.
Blue litmus paper will turn red when placed in a solution having which of the following ph values?
D: Blue litmus paper turns red when placed in an acid solution. A ph below 7 indicates an acid.
Given the unbalanced equation __KClO3 > ___KCl + ___O2 What is the coefficient of O2 in the balanced equation?
C: A balanced equation contains the same number of atoms of each element on both sides of the written reaction: 2KClO3 > 2KCl + 3O2.
The compound H2SO4 is an example of?
a. a salt
b. a base
c. an acid
d. a halogen
C: H2SO4 is sulfuric acid. Acid may be defined as substances that release hydrogen ions in solution as the only positive ions. they may also be seen as protons donors. Bases release hydroxide ions, and salts have neither H+ or OH- ions. Halogens are elements.
Many people believe that some trees drop their leaves in the late fall because the temperature is near freezing. Which of the following statements least supports this idea?
a. Maple trees in northern Minnesota drop their leaves in late fall.
b. Maple trees growing near city lights stay green longer than those far from the lights.
c. Maple trees pass through a time of near freezing before they bud
d. Maple trees in southern Florida drop their leaves in late fall
D: The statement supports the idea that leaves are dropped due to the temperature, because the temperature in southern Florida in late fall is not freezing, yet the leaves are dropping. The key word in the question is "least".
Which of the following is considered a principal ecological role of green plants in the environment?
a. providing shade to regulate the environmental temperature
b. using the mineral content of the soil
c. providing nesting places for animals
d. manufacturing food from simple materials
D: Plants undergo photosynthesis, which allows them to make glucose from the simple materials carbon dioxide and water.
In a flask containing 500 mL of NaCl(aq), the solvent is?
B: The notation "(aq)" refers to an aqueous solution, indicating that the solvent is water.
The diameter of the low-power field of a certain microscope is 1.6 mm. The diameter of a cell that is half the diameter of the field is?
a. 500 um
b. 800 um
c. 1000 um
d. 1600 um
D: One half of the field = 800 um: 1 mm = 1,000 um, and 1.6 mm = 1,600 um.
Twenty-five milliliters of a saline solution contains 5g of NaCl. What percentage solution is it?
C: We assume that 1 mL of water has a mass of 1g. So 25 mL equals 25g. Divide 5 by 25 and convert to percentage.
In pea plants, plant height and seed color obey the law of independent assortment. If seeds are hybrid for both of these traits, how will their offspring most likely appear?
a. all tall, with green seeds
b. all short, some with yellow and some with green seeds
c. some tall and some short, with all green seeds
d. some tall and some short, with green or yellow seeds
D: The law of independent assortment states that traits are passed onto offspring independently of each other. Thus, a seed may contain either of the height alleles and either of the color alleles.
During the 1930s and through the 1950s, thousands of American children received x-ray treatment for swollen tonsils and adenoids. X-rays are no longer used to treat this condition because large doses of radiation?
a. were found to stimulate excessive hair growth
b. are thought to cause certain types of cancer
c. are thought to increase the severity of acne during adolescence
d. were found to increase the number of cases of tonsillitis.
B: Radiation exposure has been linked to cancer.
A student studies a structure microscopically and notes that it contains glandular cells. It has blood vessels entering and leaving it, but it has no duct leading out of it. The structure must be?
a. an endocrine gland
b. an excretory gland
c. a digestive gland
d. a tear gland
A: Endocrine glands are ductless glands with blood vessel associations. Exocrine glands, such as digestive and tear glands, empty their secretions through ducts.
Which laboratory reagent turns starch blue-black?
b. Benedict's solution
c. nitric acid
d. Lugol's solution
D: Lugol's solution (iodine plus potassium iodide) is an indicator that turns blue-black in the presence of starch.
What types of body cells are most directly involved when a person walks up hill?
a. smooth muscle cells
b. subcutaneous cells
c. striated muscle cells
d. epithelial cells
C: Muscles are the tissues mostly involved when a person is exercising. Smooth muscle is found in the lining of organs such as the uterus. Skeletal muscle, such as that found in the muscles of the legs and arms is striated.
When red food coloring is added to a beaker of water, the coloring slowly spreads until the water is all colored pink. This is best explained by the process of?
c. active transport
B: A drop of food coloring will slowly diffuse through the beaker of water until it reaches equilibrium when it will be fully dispersed. It moves from the area of greater concentration to the area of lower concentration.
Many chemical reactions occur more rapidly with platinum as a catalyst. At the end of the reaction, the platinum is found to be?
a. increased in quantity
b. unchanged in weight
c. changed into another state
d. combined into the final product
B: A catalyst only affects the rate of a reaction and is not changed or consumed during it.
Which formula represents a carbohydrate?
D: A carbohydrate is made up of carbon, hydrogen and oxygen with the ration of hydrogen to oxygen 2:1.
When looking through a microscope, a student observes centrosomes in a group of cells. The cells are most likely from the?
a. root of a bean plant
b. leaf of a moss
c. skin of a mouse
d. stem of a fern
C: A centrosome is an organelle found in animal cells.
Ohm's law is used tin the study of?
A: Ohm's law applies to the study of electricity. It states that voltage (V) is proportional to current (I) and resistance (R):V=IR.
A cloud chamber is a device used for?
a. studying the formation of weather systems
b. recreating the atmosphere of the primitive earth
c. treating a respiratory infection
d. studying charged particles
D: A cloud chamber makes the paths of ionizing radiation rays visible. the device reveals the paths of high-speed charged particles.
Which of these temperatures could not occur?
a. -0 C
b. -10 K
c. 2,000 F
d. 104 C
B: Zero Kelvin is absolute zero, which is the lowest possible temperate; therefor, -10 Kelvin does not exist.
Which organisms are classified as protists?
a. protozoa, bacteria, and worms
b. fungi, ferns, and mollusks
c. monkeys, apes, and man
d. protozoa and algae
D: Bacteria are in the kingdom Monera. Worms, mollusks, humans, apes and monkeys are in the kingdom Animalia. Ferns are in the kingdom Plantae, and fungus is in the kingdom Fungi. Protozoa and algae are Protists..
How much of 12g of a radioactive isotope with a half-life of 20 years will be left after 40 years?
B: Half-life is the amount of time it takes for one half of the mass of a sample of radioactive substance to decay. In 20 years a 12-g isotope with a half-life of 20 years will be 6g. Twenty years after the the isotope will be 3g.
Two atoms are isotopes if they have the same atomic number but a different number of?
A: An example of isotopes are carbon-12 and carbon-14. Both have the same atomic number (number of protons), but although carbon-12 contains 6 neutrons, carbon-14 contains 8 neutrons.
Shivering to maintain a 98.6F Temperature in cold weather is an example of?
A: Homeostasis is the maintenance of a stable internal environment.
If a plain Soda cracker is chewed slowly, after a while it begins to taste more?
B: The enzyme amylase, which is found in saliva breaks down the starches present in food, such as crackers into sugars.
The scientific name of a beaver is Castor Canadensis. Similarly, a coyote is Canis latrans, a mountain lion is Felis concolor, a wolf is Canis lupus, and a cougar is Puma concolor. Which two of these animals belong to the same genus?
a. beaver and wolf
b. cougar and mountain lion
c. coyote and wolf
d. mountain lion and cougar
C: The wolf and the coyote both belong to the genus Canis. the scientific name consists of the genus name and the species name.
The first step by which a mutation my occur is a change in the ?
a. location of a nitrogen base in DNA
b. messenger RNA
c. transfer RNA
d. amino acid in a protein synthesis
A: The sequence of messenger RNA, transfer RNA, and amino acids in protein synthesis all depend on the sequence of DNA found in the nucleus. Thus the fist step in which a mutation may occur is at the level of the DNA, which is made up of a specific sequence of basis.
In the equilibrium system A + B <> C + 30 kcal we can say that the?
a. reverse reaction is exothermic
b. forward reaction is exothermic
c. reverse reaction requires a catalyst
d. forward reaction is endothermic
B: The forward reaction is exothermic because heat is shown as one of the products. The reverse reaction is endothermic since heat is shown as a product. We do not know about a catalyst from the information given.
A compound that can act like either an acid or a base is described as?
A: An amphoteric substance can behave either as an acid or a base. Water is an example of an amphoteric substance because it can act as an acid by furnishing a proton, or it can act as a base by accepting a proton.
The diffusion of water through a semipermeable membrane is called?
c. active transport
B: Osmosis is the diffusion of water from areas that contain a high concentration of water to area that contains a low concentration of water.
Bean plant seeds are germinated in a dark closet. The seedlings lack the color green. Which of the following statements is the best explanation for this?
a. Bean plants are heterotrophs
b. Bean seedlings lack nitrogen in their seed leaf
c. The absence of an environmental factor limits the proper genetic expression
d. Bean plants cannot be classified as green plants
C: The seedlings lacked light, which interfered with their development.
An organism that has jointed legs, an exoskeleton, and a specialized segmented body belongs to the phylum of?
C: An example of an arthropod is a lobster.
Nerve impulses form the retina are transmitted to the brain by the?
a. olfactory nerve
b. optic nerve
c. Eustachian tube
d. auditory nerve
B: The Eustachian tube and auditory nerve are associated with the ear, and the olfactory nerve is involved with the sense of smell.
In which of these structures does the normal development of a human embryo occur?
B: The ovary releases the egg into the oviduct, or fallopian tube where it is fertilized. If fertilization occurs, the zygote travels to the uterus, where it implants itself and develops.
In humans, which of these blood components carries most of the oxygen?
b. white blood cells
d. red blood cells
D: Red blood cells contain hemoglobin, which binds, transports and delivers oxygen throughout the body.
Compound A reacts with compound B to give compound C plus compounds D and E, as shown by the following equation: A+B> C+D+E If in a closed system, 7g A react with 4g B to give 2g C plus 3g E, how many grams of D are produced?
B: The law of conservation of mass says that mass may be neither created nor destroyed. Therefor, the mass of the reactants must be equal to the mass of the products of a reaction.
Which of the following statements best describes how pressure and volume are affected as a sample of ideal gas is heated in a rigid, sealed container?
a. neither pressure nor volume will increase
b. pressure will remain constant, and volume will increase
c. both pressure and volume will decrease
d. pressure will increase, and volume remains constant
D: A rigid container implies no change in volume. According to Gay-Lussac's law, at constant volume an increase in temperature cause and increase in pressure and vice versa.
An object is traveling at a constant velocity of 100m/sec. How far will it travel in 20 sec?
D: Distance traveled is directly proportional to velocity and time. Distance = velocity x time, distance = 100m/secx20sec=2,00m
A student placed a stone in a gradulated cylinder containing 30cm3 of water. She then noted that the water level rose to 55cm3 mark. What is the volume of the stone?
A: The stone causes the volume in the cylinder to increase by 25cm3 (55cm3-30cm3). The volume of a liquid displaced by a submerged object is equal to the volume of the object itself. Therefor, the volume of the stone is 25 cm3.
A 36-W lam is operated by a 9-V battery. How many amperes of current are flowing through the lamp?
a. 0.25 A
b. 4 A
c. 27 A
d. 45 A
B: Power = Voltage x current; 36w = 9v x current; current = 4a
Which of the following terms are included in the scientific name of an organism?
a. genus and species
b. phylum and species
c. family and genus
d. kingdom and phylum
A: Genus and species make up the scientific name of an organism.
Which of the following would be classified as an example of connective tissue?
a. striated muscle
D: Connective tissue binds and supports other tissues. For example, tendons attach muscle to bone. Muscle is muscular tissue, epidermis is epithelial tissue, and nerve is nervous tissue.
The entry and exit of materials in the animal cell are regulated by which of these cell organelles?
b. cell wall
c. endoplasmic reticulum
d. plasma membrane
D: The plasma mermbrasne, which is make of carbohydrates, lipids and proteins, is selectively permaeable and regulates traffic into and out of a cell.
Which of the following structures is the functional unit of the human lung?
b. Malpighian tubule
D: Alveoli are the functional units of lungs. The oviduct, or fallopian tube, conveys the released egg to the uterus. Malpighian tubules are excreatory organs found in insects, and the nephron is the functional unt of the kidneys.
Which of these substances is an end product of protein digestion?
a. amino acids
c. fatty acids
A: Proteins are made up of chains of amino acids.
If a person's gallbladder were removed by surgery, which of the following substances would he have the most difficulty digesting?
b. nucleic acids
C: The gallbladder stores bile, which is the substance produced by the liver. Bile contains bile salts, which aid in the digestion and absorption of fats.
Which of the following phenomena is most likely to speed the evolutionary rate of a species?
a. lack of environmental changes
b. increase in mutations
c. decrease in migration
d. increase in death rate
B: Mutations of DNA are the orginal source of variation and alter the gene pool in a population. An increase in the number of mutations increases the variation in the gene pool and thus speeds up the evolutionary rate of a species.
The code of a gene is delivered to the protein-producing region of a cell by?
A: Messenger RNA (m-RNA) carries the information contained in DNA molecule to the ribosome where proteins are made. t-RNA carries amino acids to the ribosome. ATP is involved in the storage of energy and not genetics.
Which of the following particles are nucleons?
a. neutrons and electrons
b. electrons, protons and neutrons
c. neutrons and protons
d. electrons, photons, and neutrons
C: Neutrons and protons are contained in the nucleus of an atom, whereas electrons reside outside the nucleus.
Quantities having both magnitude and direction are called?
a. line segments
C: By definition, vectors are quantities with magnitude and direction.
Which of the following statements best describes the functioning of a battery?
a. it changes chemical energy into electrical energy
b. it stores electricity
c. it creates electrons
d. it changes current into voltage
A: In an electrochemical cell, which makes up a battery, chemical energy is converted into electric current.
A 4-N (-newton) and an 18-N force are acting in opposite directions on the same point of an object. The magnitude of their resultant is?
B: When two forces act in opposite directions, the total force is determined by subtracting the smaller force from the larger one.
Which of the following equations represents aerobic respiration?
a. C6H12O6 + 6O2 > 6CO2 + 38ATP
b. C6H12O6 + C6H12O6 > C12H22O11 + H2O
c. C6H12O6 > 2CO2 + 2C2H5OH + 2ATP
d. 6CO2 + 12H2O > C6H12O6 + 6O2 + 6H2O
A: Aerobic respiration is the breakdown of glucose and the formation of energy. The reaction shown in equation D is the reverse of aerobic respiration: photosynthesis. Equation C represents fermentation (anerobic), and equation B shows dehydration synthesis.
An overdose of a muscle relaxant may cause a person to cease breathing because?
a. the diaphragm will be unable to contract
b. the lung muscles will cease to function
c. the muscles around the trachea will constrict
d. the alveoli will constrict
A: The diaphragm must contract for inhalation to occur, and, as a muscle, the diaphragm is affected by the muscle relaxant.
A decrease in acetylcholine synthesis in humans would most likely lead to?
a. an increase in protein digestion
b. a decrease in nerve impulse transmission
c. an increase in muscular activity
d. a decrease on white blood cells
B: Acetylcholine is a common neurotransmitter. Neurotransmitters act as chemical messengers and spread informtation from one neuron to the next.
An unknown substance is boiled with Benedict's solution The brick red color that results indicates the presence of?
D: Benedict's solution is used to indicate the presence of monosaccharides, glucose.
Which are herbivores?
a. green plants
B: Herbivores are animals that feed on plants. Thus, insects are herbivores because they consume green plants.
According to this pyramid to support 100 lb of birds, which of the following is needed?
a. more then 100 lb of insects
b. more than 100 lb of snakes
c. less than 100 lb of green plants
d. 100 lb of insects
A: The diagram increases in size in the direction of birds to insects, indicating that more insects are required to support a certain amount of birds. Thus, 100 pounds of birds will consume an amount of insects excedding 100 pounds.
Ozone is an allotrope of?
C: Ozone (O3) is an allotrope of oxygen. It is a molecule made up of more than two atoms of the same element.
Which of these values could be the ph of an acid rain sample?
D: Acid rain has an acidic pH. A substance with a pH between 0 and 7 is an acid.
A specific isotope has an atomic number of 51 and a mass number of 122. How many electrons are contained in the neutral atom?
A: The mass number is the sum of the number of protons and neutrons. The atomic number is the number of protons, which is always equal to the number of electrons in a neural atom.
A mixture such as mayonnaise is best described as?
a. a substance
c. a solution
d. an emulsion
D: Mayonnaise is made up of oil, vinegar and eggs which form a type of heterogeneous mixture called an emulsion. An emulsion will eventuallly separate, while a solution will not. The terms "saturated" and "unsaturated" refer to solutions. Mixtures are not substances.
Which of the following terms is the SI unit for work?
A: The joule is the unit of energy equal to the work done by a force of 1 N acting over a distance of 1 m.
A woman standing at a bus stop hears the siren of an approaching ambulance. As the ambulance passes by her, she observes a shift in the frequency of the siren. The effect she heard is known as the?
a. photoelectric effect
b. Doppler effect
c. phase shift effect
d. Einstein effect
B: The Doppler effect occurs whenever there is a relative morion between the source of the sound waves and the observer. The pitch of a siren becomes higher as it approaches you and lower as it drives away. the siren has not changed its frequency, byt the motion of the siren toward you increases the frequency of the sound waves you hear.
The pitch of ta vibrating string depends on all of the following except?
a. the length of the string
b. the amplitude of the vibration
c. the thickness of the string
d. the frequency of the vibration
B: Observed pitch is independeent of the amplitude of the vibration. The amplitude is related to the loudness of the sound. The pitch of a string is affected by thickness, length, and frequency.
The specific heat of water is 1 cal/g/C. How many calories of heat are needed to raise the temperature of 30g of water from 25 C to 75 C.
a. 50 Cal
b. 750 Cal
c. 1,500 Cal
d. 2,250 Cal
C: The specific heat capacity of a substance is the heat required to raise the temperature of 1g of a specific substance by 1C. In the case of water, the specific heat capacity is 1 Cal/g/C. In this situation, you want to change 30g of water by 50C.
As the angle of incidence of a ray of light striking a mirror increases, the angle of reflection will?
c. remain the same
d. first increase, then remain constant
A: ccording to the law of reflection, the angle of incidence and the angle of reflection will be equal.
The idea that new varieties of organisms are evolving today is best supported by the?
a. increasing need for new antibiotics
b. diminishing size of the ozone layer
c. climate changes resulting in global warming
d. increasing size of the human population
A: The developement of resistant strains of bacteria, thus prompting the need for new antibiotics, is an example of evolution occurring today. The ozone layer, global warming, and increasing population size are changes in selective pressure, but not examples of evolution.
In a food chain, an organism that feeds on green plants is known as a?
c. first-order consumer
d. second-order consumer
B: Green plants are producers because they produce their own food by means of photosynthesis. Consumers depend on other organisms for their food. A first-order (primary) consumer is an herbivore and eats plants and alge. A second-order (secondary) consumer is a carnivore and eats herbivores.
Which of the following parts of a compound microscope is used to adjust the amount of light?
b. objective lens
d. coarse adjustment knob
A: The diaphragm adjusts the amount of light in a microscope.
A cell is placed in a drop of distilled water. The cell swells and bursts. The most likely cause of this reaction is that?
a. active transport of salts occurs
b. water moves from an area of low particle concentration to an area of high particle concentration
c. water moves from an area of high particle concentration to an area of low particle concentration
d. salts from the distilled water enter the cell
B: Osmosis refers to the diffusion of water from areas that contain a high concentraion of water and low concentration of solute (outside the cell) to areas that contain a low concentration of water and high concentration of solute (inside the cell).
In pea plants, tallness is dominant over shortness. If 25% of one generation of pea plants is short, what were the probable genotypes of the parents?
a. tt x tt
b. Tt x tt
c. TT x Tt
d. Tt x Tt
D: A cross in which both of the parents are heterozygotes yields 25% TT, 50% Tt, and 25% tt.
Which of the following terms refers to the capacity of a microscope to distinguish between objects that lie very close to each other?
a. resolving power
d. magnifying power
A: Resolving power is the capacity to distinguis between objects that lie very close to each other.
Which of the following formulas is most probably for a compound formed from aluminum and sulfur? (Aluminum has an oxidation number of 3+. Sulfur has an oxidation number of 2-.)
D: The ions that make up a compound form in such a ratio as to produce a neutral compound. Thus, 2 aluminum ions (+3) are needed for 3 sulfur inos (-2each): Al2O3
Which of the following is not used as a means of separating mixtures?
B: Filtration, chromatography, and distillation are means of separatiing componets of mixtures (physical means). Electrlysis is used to decompose compounds, as in the electrolysis of water.
The law of chemical equilibrium states that in the reversible reaction N2 + 3H2 > 2NH3 the equilibrium constant is expressed as?
(the equations are long so I am only putting the answer down.)
Which of the following elements is a nonmetal?
a. Na (sodium)
b. Hg (mercury)
c. S (sulfur)
d. Mn (manganese)
C: Sulfur is the only element listed that is not a metal.
Machines may be used for all of the following purposes except to?
a. multiply force
b. increase energy
d. transform energy
d. multiply speed
B: Conservation of energy forbids a machine from increasing energy. Machines are designed to use energy efficiently. Machines cannnot be designed to increase energy; they use energy to do work.
Please allow access to your computer’s microphone to use Voice Recording.
Having trouble? Click here for help.
We can’t access your microphone!
Click the icon above to update your browser permissions and try again
Reload the page to try again!Reload
Press Cmd-0 to reset your zoom
Press Ctrl-0 to reset your zoom
It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
Please upgrade Flash or install Chrome
to use Voice Recording.
For more help, see our troubleshooting page.
Your microphone is muted
For help fixing this issue, see this FAQ.
Star this term
You can study starred terms together