questions stringlengths 37 1.22k | reasoning stringlengths 0 3.56k ⌀ | answers stringlengths 4 138 |
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Producers, primary consumers, higher-level consumers, and decomposers are levels in what?
Here are the choices:
A. food flowchart
B. energy chain
C. food model
D. food chain | Food Chains and Food Webs A food chain is a linear sequence of organisms through which nutrients and energy pass as one organism eats another; the levels in the food chain are producers, primary consumers, higher-level consumers, and finally decomposers. These levels are used to describe ecosystem structure and dynamics. There is a single path through a food chain. Each organism in a food chain occupies a specific trophic level (energy level), its position in the food chain or food web. In many ecosystems, the base, or foundation, of the food chain consists of photosynthetic organisms (plants or phytoplankton), which are called producers. The organisms that consume the producers are herbivores: the primary consumers. Secondary consumers are usually carnivores that eat the primary consumers. Tertiary consumers are carnivores that eat other carnivores. Higher-level consumers feed on the next lower trophic levels, and so on, up to the organisms at the top of the food chain: the apex consumers. In the Lake Ontario food chain, shown in Figure 20.4, the Chinook salmon is the apex consumer at the top of this food chain. | D: food chain. |
Parthenogenis in komodo dragons is an example of what kind of reproduction, whereby offspring are created from just one parent?
Here are the choices:
A. organic reproduction
B. natural reproduction
C. benthic reproduction
D. asexual reproduction | No, not all animals have two parents. Sometimes animals can be made from just one parent. This Komodo dragon, for example, only has a mother and reproduces by parthenogenesis. Asexual reproduction is the process of creating offspring from just one parent. | D: asexual reproduction. |
The value that occurs most often in a data set is called the?
Here are the choices:
A. median
B. mode
C. mean
D. type | The mode is the most common value. It is the value that occurs most often. | B: mode. |
Over time, deposited sediments may harden into what?
Here are the choices:
A. deltas
B. fossils
C. rocks
D. coral | Over time, deposited sediments may harden into rock. First, the sediments are compacted . That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. Sedimentary rocks that form from sediments are called “clastic rocks. “ Clastic rocks are rock fragments that are compacted and cemented together ( Figure below ). | C: rocks. |
What is the most useful quantity for counting particles?
Here are the choices:
A. the mole
B. the periodic table
C. the vector
D. the coefficient | The most useful quantity for counting particles is the mole. So if each coefficient is multiplied by a mole, the balanced chemical equation tells us that 1 mole of nitrogen reacts with 3 moles of hydrogen to produce 2 moles of ammonia. This is the conventional way to interpret any balanced chemical equation. | A: the mole. |
What is the failure of replicated chromosomes during meiosis to separate known as?
Here are the choices:
A. nondisjunction
B. pollenation
C. separation
D. regression | Mistakes may occur during meiosis that result in nondisjunction . This is the failure of replicated chromosomes to separate during meiosis (the animation at the link below shows how this happens). Some of the resulting gametes will be missing a chromosome, while others will have an extra copy of the chromosome. If such gametes are fertilized and form zygotes, they usually do not survive. If they do survive, the individuals are likely to have serious genetic disorders. Table below lists several genetic disorders that are caused by abnormal numbers of chromosomes. Most chromosomal disorders involve the X chromosome. Look back at the X and Y chromosomes and you will see why. The X and Y chromosomes are very different in size, so nondisjunction of the sex chromosomes occurs relatively often. http://learn. genetics. utah. edu/content/begin/traits/predictdisorder/index. html. | A: nondisjunction. |
In angiosperms, flowers and fruits are adaptations essential for what process?
Here are the choices:
A. photosynthesis
B. reproduction
C. variation
D. death | 30.3 The reproductive adaptations of angiosperms include flowers and fruits. | B: reproduction. |
Through what part do exocrine glands discharge their contents?
Here are the choices:
A. capillaries
B. follicles
C. tubular ducts
D. urethra | Exocrine Glands Exocrine glands release their contents through a duct that leads to the epithelial surface. Mucous, sweat, saliva, and breast milk are all examples of secretions from exocrine glands. They are all discharged through tubular ducts. Secretions into the lumen of the gastrointestinal tract, technically outside of the body, are of the exocrine category. | C: tubular ducts. |
Where do plankton, nekton, and benthos live?
Here are the choices:
A. arctic
B. in the oceans
C. deserts
D. forests | Zappy's. Plankton, nekton, and benthos are the three groups of living things in the oceans . CC BY-NC 3.0. | B: in the oceans. |
What gland is a butterfly-shaped organ located in the neck anterior to the trachea?
Here are the choices:
A. pituitary gland
B. adrenal gland
C. pineal gland
D. thyroid gland | 17.4 The Thyroid Gland The thyroid gland is a butterfly-shaped organ located in the neck anterior to the trachea. Its hormones regulate basal metabolism, oxygen use, nutrient metabolism, the production of ATP, and calcium homeostasis. They also contribute to protein synthesis and the normal growth and development of body tissues, including maturation of the nervous system, and they increase the body’s sensitivity to catecholamines. The thyroid hormones triiodothyronine (T3) and thyroxine (T4) are produced and secreted by the thyroid gland in response to thyroid-stimulating hormone (TSH) from the anterior pituitary. Synthesis of the amino acid–derived T3 and T4 hormones requires iodine. Insufficient amounts of iodine in the diet can lead to goiter, cretinism, and many other disorders. | D: thyroid gland. |
What cause the rippled surface of the ocean?
Here are the choices:
A. tides
B. earthquakes
C. winds
D. waves | Waves cause the rippled surface of the ocean. | D: waves. |
What small glands are abundant within the mucous membranes of the mouth and tongue?
Here are the choices:
A. retinal glands
B. localized glands
C. hypothalamus glands
D. salivary glands | The Salivary Glands Many small salivary glands are housed within the mucous membranes of the mouth and tongue. These minor exocrine glands are constantly secreting saliva, either directly into the oral cavity or indirectly through ducts, even while you sleep. In fact, an average of 1 to 1.5 liters of saliva is secreted each day. Usually just enough saliva is present to moisten the mouth and teeth. Secretion increases when you eat, because saliva is essential to moisten food and initiate the chemical breakdown of carbohydrates. Small amounts of saliva are also secreted by the labial glands in the lips. In addition, the buccal glands in the cheeks, palatal glands in the palate, and lingual glands in the tongue help ensure that all areas of the mouth are supplied with adequate saliva. | D: salivary glands. |
What is the term for the development of an embryo inside an egg within the mother’s body until it hatches?
Here are the choices:
A. pregnancy
B. spawning
C. asexual reproduction
D. ovovivipary | Ovovivipary refers to the development of an embryo inside an egg within the mother’s body until it hatches. The mother provides no nourishment to the developing embryo inside the egg. This occurs in some species of fish and reptiles. | D: ovovivipary. |
Where does carbohydrate digestion begin in the body?
Here are the choices:
A. mouth
B. intestines
C. stomach
D. throat | Digestion of Carbohydrates Carbohydrate digestion begins in the mouth (Figure 20.5 "The Principal Events and Sites of Carbohydrate Digestion"), where salivary α-amylase attacks the α-glycosidic linkages in starch, the main carbohydrate ingested by humans. Cleavage of the glycosidic linkages produces a mixture of dextrins, maltose, and glucose. (For more information about carbohydrates, see Chapter 16 "Carbohydrates". ) The α-amylase mixed into the food remains active as the food passes through the esophagus, but it is rapidly inactivated in the acidic environment of the stomach. Figure 20.5 The Principal Events and Sites of Carbohydrate Digestion. | A: mouth. |
When did new plants start sprouting after the forest fire?
Here are the choices:
A. two months later
B. two days later
C. two weeks later
D. five months later | Secondary Succession. Two months after a forest fire, new plants are already sprouting among the charred logs. | A: two months later. |
What are the largest known proteins called?
Here are the choices:
A. titins
B. obscures
C. sporozoans
D. aminos | A protein is an organic compound made up of small molecules called amino acids . There are 20 different amino acids commonly found in the proteins of living organisms. Small proteins may contain just a few hundred amino acids, whereas large proteins may contain thousands of amino acids. The largest known proteins are titins, found in muscle, which are composed from over 27,000 amino acids. | A: titins. |
Metals, fossil fuels, and water are all examples of what type of resource?
Here are the choices:
A. natural resources
B. renewable resources
C. recyclables
D. ores | A natural resource is anything in nature that humans need. Metals and fossil fuels are natural resources. But so are water, sunlight, soil, and wind. Even living things are natural resources. | A: natural resources. |
What is the force that causes centripetal acceleration?
Here are the choices:
A. Tension Force
B. centripetal force
C. pressure
D. gravity | Centripetal force is the force that causes centripetal acceleration. | B: centripetal force. |
Pressure and ________ are directly proportional at a constant volume?
Here are the choices:
A. heating
B. speed
C. precipitation
D. temperature | Pressure and temperature are directly proportional at a constant volume. | D: temperature. |
What is the process by which plants capture the energy of sunlight and use carbon dioxide from the air (and water) to make their own food called?
Here are the choices:
A. photosynthesis
B. spermatogenesis
C. photochemistry
D. atherosclerosis | Recall that eukaryotic organisms also include animals, protists, and fungi. Eukaryotes have cells with nuclei that contain DNA, and membrane-bound organelles, such as mitochondria. Photosynthesis is the process by which plants capture the energy of sunlight and use carbon dioxide from the air (and water) to make their own food, the carbohydrate glucose. Plants have chloroplasts, the organelle of photosynthesis, and are known as producers and autotrophs. Other organisms are heterotrophic consumers, meaning they must obtain their nutrients from another organism, as these organisms lack chloroplasts. Lastly, plants must be multicellular, composed of more than one cell. There are no single-celled plants. Recall that some protists, such as algae, are eukaryotic and photosynthetic but are not considered plants. Unlike plants, algae is mostly unicellular. | A: photosynthesis. |
Categorized based on how they produce their mrna using the baltimore classification method, what consist of a nucleic acid core surrounded by a protein capsid with or without an outer lipid envelope?
Here are the choices:
A. parasites
B. viruses
C. bacteria
D. amphibians | CHAPTER SUMMARY 21.1 Viral Evolution, Morphology, and Classification Viruses are tiny, acellular entities that can usually only be seen with an electron microscope. Their genomes contain either DNA or RNA—never both—and they replicate using the replication proteins of a host cell. Viruses are diverse, infecting archaea, bacteria, fungi, plants, and animals. Viruses consist of a nucleic acid core surrounded by a protein capsid with or without an outer lipid envelope. The capsid shape, presence of an envelope, and core composition dictate some elements of the classification of viruses. The most commonly used classification method, the Baltimore classification, categorizes viruses based on how they produce their mRNA. | B: viruses. |
Primary alcohols are oxidized to form what?
Here are the choices:
A. aldehydes
B. enzymes
C. oxides
D. alloys | Primary alcohols are oxidized to form aldehydes. | A: aldehydes. |
Where does electric power originate?
Here are the choices:
A. the Sun
B. power plants
C. coal mines
D. magnets | Power plants are where electric power originates. They have electric generators that generate electric current through electromagnetic induction. | B: power plants. |
What type of fertilization do most reptiles use to reproduce?
Here are the choices:
A. internal
B. external
C. asexual
D. mechanical | After food is broken down into nutrient molecules, the molecules are absorbed by the blood. Absorption is the process in which nutrients or other molecules are taken up by the blood. Once absorbed by the blood, nutrients can travel in the bloodstream to cells throughout the body. | A: internal. |
Visible light is part of what spectrum?
Here are the choices:
A. electromagnetic spectrum
B. molecular spectrum
C. eclipse spectrum
D. mechanical spectrum | Visible light is part of the electromagnetic spectrum. | A: electromagnetic spectrum. |
Amino acids are made by which kind of plastid?
Here are the choices:
A. neuroplasts
B. sporozoans
C. leucoplasts
D. glucoplasts | Leucoplasts are plastids that store substances such as starch or make small molecules such as amino acids. | C: leucoplasts. |
The amount of power passed through transmission lines can be calculated by multiplying voltage by what?
Here are the choices:
A. amplification
B. induction
C. current
D. resistance | The amount of power passed through transmission lines can be calculated by multiplying voltage by current. The same power can be transmitted using a very high voltage and a very low current as with a low voltage and high current. | C: current. |
When a balloon is rubbed against hair, they attract each other because of a difference in what?
Here are the choices:
A. actions
B. Force
C. charges
D. Friction | Did you ever rub an inflated balloon against your hair? You can see what happens in Figure below . Friction between the rubber of the balloon and the baby’s hair results in electrons from the hair "rubbing off" onto the balloon. That’s because rubber attracts electrons more strongly than hair does. After the transfer of electrons, the balloon becomes negatively charged and the hair becomes positively charged. As a result, the individual hairs repel each other and the balloon and the hair attract each other. Electrons are transferred in this way whenever there is friction between materials that differ in their ability to give up or accept electrons. | C: charges. |
The cell starting meiosis is called a what?
Here are the choices:
A. primary gamete
B. secondary oocyte
C. primary oocyte
D. zygote | The cell starting meiosis is called a primary oocyte, as shown in Figure 43.13. This cell will start the first meiotic division and be arrested in its progress in the first prophase stage. At the time of birth, all future eggs are in the prophase stage. At adolescence, anterior pituitary hormones cause the development of a number of follicles in an ovary. This results in the primary oocyte finishing the first meiotic division. The cell divides unequally, with most of the cellular material and organelles going to one cell, called a secondary oocyte, and only one set of chromosomes and a small amount of cytoplasm. | C: primary oocyte. |
A wave is the transfer of energy through what else?
Here are the choices:
A. air
B. liquid
C. gas
D. matter | Most ocean waves are caused by winds. A wave is the transfer of energy through matter. A wave that travels across miles of ocean is traveling energy, not water. Ocean waves transfer energy from wind to the water. The energy is transferred from one water molecule to the next. The energy of a wave may travel for thousands of miles. The water itself moves very little. The picture below shows how water molecules move when a wave goes by ( Figure below ). Once the wave starts, it doesn't need more wind to keep it going. | D: matter. |
What nest of cells protect the egg as it matures in the ovary?
Here are the choices:
A. the follicle
B. the epidermis
C. the clump
D. the tube | As you can see from the figure, the egg rests in a nest of cells called a follicle . The follicle and egg grow larger and go through other changes. The follicle protects the egg as it matures in the ovary. | A: the follicle. |
Why do beer brewers add yeast to the wort?
Here are the choices:
A. increase longevity
B. add carbonation
C. to make alcohol
D. reduce alcohol | Brewers of beer and wine use yeast to add alcohol to beverages. Traditional varieties of yeast not only make but also limit the quantity of alcohol in these beverages, because above 18% by volume, alcohol becomes toxic to the yeast itself. Wine is produced by fermentation of the natural sugars present in grapes and other kinds of fruit. Beer, whiskey, and vodka are produced by fermentation of grain starches that have been converted to sugar by the enzyme amylase, and rum is produced by fermentation of sugarcane. In each of these fermentations, sugars are converted into small amounts of ATP, using and regenerating NAD + in the process, and producing ethanol and carbon dioxide. Scientists have recently developed new strains of yeast which can tolerate up to 25% alcohol by volume. These are used primarily in the production of ethanol fuel. | C: to make alcohol. |
Amino acids broken down by metabolic process are mostly recycled into new what?
Here are the choices:
A. hormones
B. proteins
C. lipids
D. enzymes | Connections of Proteins to Glucose Metabolism Proteins are broken down by a variety of enzymes in cells. Most of the time, amino acids are recycled into new proteins. If there are excess amino acids, however, or if the body is in a state of famine, some amino acids will be shunted into pathways of glucose catabolism. Each amino acid must have its amino group removed prior to entry into these pathways. The amino group is converted into ammonia. In mammals, the liver synthesizes urea from two ammonia molecules and a carbon dioxide molecule. Thus, urea is the principal waste product in mammals from the nitrogen originating in amino acids, and it leaves the body in urine. | B: proteins. |
What type of logic can lead to important conclusions from the collecting and analyzing of observations?
Here are the choices:
A. conductive reasoning
B. primitive reasoning
C. gravitational reasoning
D. inductive reasoning | D: inductive reasoning. | |
Screws move objects to a higher elevation by increasing what?
Here are the choices:
A. kinetic energy
B. force applied
C. torque
D. velocity | The spiral staircase in Figure below also contains an inclined plane. Do you see it? The stairs that wrap around the inside of the walls make up the inclined plane. The spiral staircase is an example of a screw. A screw is a simple machine that consists of an inclined plane wrapped around a cylinder or cone. No doubt you are familiar with screws like the wood screw in Figure below . The screw top of the container in the figure is another example. Screws move objects to a higher elevation (or greater depth) by increasing the force applied. | B: force applied. |
What is the second state of photosynthesis?
Here are the choices:
A. morton cycle
B. Phillip cycle
C. glover cycle
D. calvin cycle | D: calvin cycle. | |
What is the only amphibian without legs?
Here are the choices:
A. newts
B. frogs
C. caecilians
D. alligators | Frogs and toads are adapted for jumping. Salamanders and newts may walk or swim. Caecilians live in the water or soil and are the only amphibians without legs. | C: caecilians. |
Most organisms could not survive without what being present to speed up biochemical reactions?
Here are the choices:
A. vitamins
B. enzymes
C. hormones
D. lipids | Enzymes are involved in most biochemical reactions, and they do their job extremely well. A typical biochemical reaction could take several days to occur without an enzyme. With the proper enzyme, the same reaction can occur in just a split second! Without enzymes to speed up biochemical reactions, most organisms could not survive. The activities of enzymes depend on the temperature, ionic conditions, and the pH of the surroundings. Some enzymes work best at acidic pHs, while others work best in neutral environments. | B: enzymes. |
Metabolic cooperation between different prokaryotic species often occurs in surface-coating colonies. what are these colonies called?
Here are the choices:
A. eukaryotes
B. biofilms
C. lichens
D. plankton | B: biofilms. | |
What word describes a carbonyl where the carbon atom makes single bonds with two others?
Here are the choices:
A. ketones
B. acetone
C. ions
D. photons | Ketones are carbonyls in which the carbon atom makes single bonds with two other carbon atoms. Ketones are less reactive than aldehydes and are a common component in nail polish removers and paint strippers. | A: ketones. |
The concentration of hydronium ions in a solution is known as what?
Here are the choices:
A. pH value
B. akaline
C. base
D. acidity | The concentration of hydronium ions in a solution is known as acidity . In pure water, the concentration of hydronium ions is very low; only about 1 in 10 million water molecules naturally breaks down to form a hydronium ion. As a result, pure water is essentially neutral. Acidity is measured on a scale called pH , as shown in Figure below . Pure water has a pH of 7, so the point of neutrality on the pH scale is 7. | D: acidity. |
What do we call structures that are similar in related organisms because they were inherited from a common ancestor?
Here are the choices:
A. filamentous
B. monogamous
C. homologous
D. polylogous | Homologous structures are structures that are similar in related organisms because they were inherited from a common ancestor. These structures may or may not have the same function in the descendants. Figure below shows the hands of several different mammals. They all have the same basic pattern of bones. They inherited this pattern from a common ancestor. However, their forelimbs now have different functions. | C: homologous. |
What is continually released during childbirth through a positive feedback mechanism and prompts uterine contractions to fetal head toward the cervix?
Here are the choices:
A. hemoglobin
B. oxytocin
C. insulin
D. vasopressin | muscle cells of the uterus become more sensitive to its effects. Oxytocin is continually released throughout childbirth through a positive feedback mechanism. As noted earlier, oxytocin prompts uterine contractions that push the fetal head toward the cervix. In response, cervical stretching stimulates additional oxytocin to be synthesized by the hypothalamus and released from the pituitary. This increases the intensity and effectiveness of uterine contractions and prompts additional dilation of the cervix. The feedback loop continues until birth. Although the mother’s high blood levels of oxytocin begin to decrease immediately following birth, oxytocin continues to play a role in maternal and newborn health. First, oxytocin is necessary for the milk ejection reflex (commonly referred to as “let-down”) in breastfeeding women. As the newborn begins suckling, sensory receptors in the nipples transmit signals to the hypothalamus. In response, oxytocin is secreted and released into the bloodstream. Within seconds, cells in the mother’s milk ducts contract, ejecting milk into the infant’s mouth. Secondly, in both males and females, oxytocin is thought to contribute to parent–newborn bonding, known as attachment. Oxytocin is also thought to be involved in feelings of love and closeness, as well as in the sexual response. | B: oxytocin. |
What is the addition of nucleotides to the mrna strand?
Here are the choices:
A. axons
B. elevation
C. elongation
D. insertion | Elongation is the addition of nucleotides to the mRNA strand. RNA polymerase reads the unwound DNA strand and builds the mRNA molecule, using complementary base pairs. There is a brief time during this process when the newly formed RNA is bound to the unwound DNA. During this process, an adenine (A) in the DNA binds to an uracil (U) in the RNA. | C: elongation. |
Wave amplitude and wavelength are two important measures of what?
Here are the choices:
A. wave harmfulness
B. wave speed
C. wave sound
D. wave size | Wave amplitude and wavelength are two important measures of wave size. | D: wave size. |
What is the color of mercury(ii) oxide?
Here are the choices:
A. blue
B. green
C. copper
D. red | Mercury(II) oxide is a red solid. When it is heated to a temperature above 500°C, it easily decomposes into mercury and oxygen gas. The red color of the mercury oxide reactant becomes the silver color of mercury. The color change is the sign that the reaction is occurring. | D: red. |
How many hydrogen atoms does a nitrogen atom of a primary amine have?
Here are the choices:
A. ten
B. four
C. six
D. two | The nitrogen atom of a primary amine is bonded to two hydrogen atoms and one carbon. The nitrogen atom of a secondary amine is bonded to one hydrogen and two carbons. The nitrogen atom of a tertiary amine is bonded to three carbon atoms. Amines are typically named by a common system rather than by IUPAC guidelines. The common system for naming amines along with several examples is shown below. | D: two. |
What ultimately results in the cycling of nutrients in ecosystems?
Here are the choices:
A. molecules between organisms
B. digestion
C. interactions between organisms
D. chemical bonds | C: interactions between organisms. | |
Platforms, arches, and sea stacks are all landforms created by what?
Here are the choices:
A. sediment
B. erosion
C. volcanic activity
D. debris | Some landforms created by erosion are platforms, arches, and sea stacks. | B: erosion. |
The state of matter - solid, liquid, or gas - is also considered what type of property?
Here are the choices:
A. thermal
B. physical
C. mechanical
D. chemical | Matter typically exists in one of three states: solid , liquid , or gas . The state a given substance exhibits is also a physical property. Some substances exist as gases at room temperature (oxygen and carbon dioxide), while others, like water and mercury metal, exist as liquids. Most metals exist as solids at room temperature. All substances can exist in any of these three states. | B: physical. |
Panting allows dogs to get rid of what?
Here are the choices:
A. excess body heat
B. calories
C. accumulated toxins
D. fur balls | Dogs pant to lose excess body heat. | A: excess body heat. |
What is the standard unit for mass?
Here are the choices:
A. ounce
B. pound
C. kilogram
D. meter | The standard unit for mass is the kilogram . The kilogram's standard is a block of platinum-iridium metal kept near Paris, France. Other countries, of course, keep copies. A kilogram is denoted "kg" and is a multiple of the smaller unit of mass, the gram ("g"). | C: kilogram. |
The planets orbit around what celestial body?
Here are the choices:
A. sun
B. earth
C. horizon
D. moon | The orbits of the planets lie in nearly the same plane. The Sun is at the center. | A: sun. |
What kind of behaviors are adaptive because they are flexible, capable of changing if the environment changes?
Here are the choices:
A. studied behavior
B. human
C. passed behavior
D. learned behavior | Learned behaviors are adaptive because they are flexible. They can change if the environment changes. | D: learned behavior. |
What is the term for a galaxy that is a rotating disk of stars and dust?
Here are the choices:
A. spiral galaxy
B. Milky Way
C. nebula
D. cosmic galaxy | A spiral galaxy is a rotating disk of stars and dust. In the center is a dense bulge of material. Several spiral arms come out from the center. Spiral galaxies have lots of gas and dust and many young stars. The image below ( Figure below ) shows a spiral galaxy from the side. You can see the disk and central bulge. | A: spiral galaxy. |
What occurs when a former inhabited area gets disturbed?
Here are the choices:
A. primary succession
B. tropical succession
C. secondary succession
D. tertiary succession | Secondary succession occurs in a formerly inhabited area that was disturbed. | C: secondary succession. |
The chloroplasts contained within the green algal endosymbionts still are capable of what process associated with plants?
Here are the choices:
A. germination
B. respiration
C. reproduction
D. photosynthesis | Several lines of evidence support that chlorarachniophytes evolved from secondary endosymbiosis. The chloroplasts contained within the green algal endosymbionts still are capable of photosynthesis, making chlorarachniophytes photosynthetic. The green algal endosymbiont also exhibits a stunted vestigial nucleus. In fact, it appears that chlorarachniophytes are the products of an evolutionarily recent secondary endosymbiotic event. The plastids of chlorarachniophytes are surrounded by four membranes: The first two correspond to the inner and outer membranes of the photosynthetic cyanobacterium, the third corresponds to the green alga, and the fourth corresponds to the vacuole that surrounded the green alga when it was engulfed by the chlorarachniophyte ancestor. In other lineages that involved secondary endosymbiosis, only three membranes can be identified around plastids. This is currently rectified as a sequential loss of a membrane during the course of evolution. The process of secondary endosymbiosis is not unique to chlorarachniophytes. In fact, secondary endosymbiosis of green algae also led to euglenid protists, whereas secondary endosymbiosis of red algae led to the evolution of dinoflagellates, apicomplexans, and stramenopiles. | D: photosynthesis. |
What do seismic waves prove about the inner core?
Here are the choices:
A. it is solid
B. it is layered
C. it is liquid
D. it is hot | Seismic waves show that the outer core is liquid. The inner core is solid. | A: it is solid. |
What is divided during cytokinesis?
Here are the choices:
A. nucleus
B. chromosomes
C. cytoskeleton
D. cytoplasm | Cell division Mitosis M Cell growth stops at this stage. Mitosis divides the nucleus into two nuclei, followed by cytokinesis which divides the cytoplasm. Two genetically identical daughter cells result. | D: cytoplasm. |
Materials such as metals have low resistance to electric current, what are they called?
Here are the choices:
A. electric conduit
B. electric channel
C. electric channels
D. electric conductors | All materials have some resistance, but certain materials resist the flow of electric current more or less than other materials do. Materials such as plastics have high resistance to electric current. They are called electric insulators. Materials such as metals have low resistance to electric current. They are called electric conductors. | D: electric conductors. |
An alloy is a mixture of what with one or more other substances?
Here are the choices:
A. acid
B. metal
C. protein
D. water | Like salt water in the ocean, many solutions are normally in the liquid state. However, matter in any state can form a solution. An alloy, which is a mixture of a metal with one or more other substances, is a solid solution at room temperature. For example, the alloy bronze is a solution of copper and tin. Matter in the gaseous state can also form solutions. | B: metal. |
A can of warm soda will fizz more because increasing the temperature decreases the what of a gas?
Here are the choices:
A. Acidity
B. viscosity
C. humidity
D. solubility | A: A can of warm soda will fizz more because increasing the temperature decreases the solubility of a gas. Therefore, less carbon dioxide can remain dissolved in warm soda than in cold soda. | D: solubility. |
What branch of biology studies animal behavior?
Here are the choices:
A. embryology
B. geology
C. microbiology
D. ethology | The branch of biology that studies animal behavior is called ethology . Ethologists usually study how animals behave in their natural environment, rather than in a lab. They generally try to answer four basic questions about the behaviors they observe:. | D: ethology. |
What does the esophagus connect to at its bottom end?
Here are the choices:
A. the colon
B. the large intestine
C. the larynx
D. the stomach | D: the stomach. | |
Hair is a component of which bodily system?
Here are the choices:
A. relatable system
B. circulatory
C. integumentary system
D. trypeta system | Well maybe not yours. But some other person's. Hair is an integral part of the integumentary system. And although many people may lose some or all of the hair on top of their head, they still have hair on their arms and legs that perform important functions. | C: integumentary system. |
What type of electrons are electrons that are not confined to the bond between two atoms?
Here are the choices:
A. internalized
B. delocalized
C. detached
D. virtualized | In benzene, the true bonding between carbon atoms is neither a single nor a double bond. Rather, all of the bonds are a hybrid of a single and double bond. In benzene, the pi bonding electrons are free to move completely around the ring. Delocalized electrons are electrons that are not confined to the bond between two atoms, but are instead allowed to move between three or more. The delocalization of the electrons in benzene can best be shown by showing benzene with a ring inside the hexagon, with the hydrogen atoms understood. | B: delocalized. |
Electrons flow through wires to create what?
Here are the choices:
A. hydroelectric power
B. electromagnetism
C. electric current
D. balanced reaction | 3. Electrical energy is the energy of moving electrons. Electrons flow through wires to create electric current. | C: electric current. |
The ileocecal valve, a sphincter, is usually in a constricted state, but when motility in the ileum increases, this sphincter relaxes, allowing food residue to enter the first portion of what?
Here are the choices:
A. liver
B. colon
C. large intestine
D. small intestine | The ileocecal valve, a sphincter, is usually in a constricted state, but when motility in the ileum increases, this sphincter relaxes, allowing food residue to enter the first portion of the large intestine, the cecum. Relaxation of the ileocecal sphincter is controlled by both nerves and hormones. First, digestive activity in the stomach provokes the gastroileal reflex, which increases the force of ileal segmentation. Second, the stomach releases the hormone gastrin, which enhances ileal motility, thus relaxing the ileocecal sphincter. After chyme passes through, backward pressure helps close the sphincter, preventing backflow into the ileum. Because of this reflex, your lunch is completely emptied from your stomach and small intestine by the time you eat your dinner. It takes about 3 to 5 hours for all chyme to leave the small intestine. | C: large intestine. |
A sequence of amino acids in single polypeptide is the primary structure for what?
Here are the choices:
A. dna
B. proteins
C. lipids
D. cells | Protein Structure. Primary protein structure is the sequence of amino acids in a single polypeptide. Secondary protein structure refers to internal shapes, such as alpha helices and beta pleated sheets, that a single polypeptide takes on due to bonds between atoms in different parts of the polypeptide. Tertiary protein structure is the overall three-dimensional shape of a protein consisting of one polypeptide. Quaternary protein structure is the shape of a protein consisting of two or more polypeptides. For a brief animation of protein structure, see www. stolaf. edu/people/giannini/flashanimat/proteins/protein%20structure. swf . | B: proteins. |
What type of chemicals do ants communicate with?
Here are the choices:
A. pesticides
B. Alkanes
C. hormones
D. pheromones | We must use energy to get energy resources. This is true of non-renewable and renewable energy. Getting fossil fuels so that they can be used takes many steps. All of these steps use energy. | D: pheromones. |
The age of a rock in years is its?
Here are the choices:
A. full age
B. chemical age
C. geological age
D. absolute age | The age of a rock in years is its absolute age . Absolute ages are much different from relative ages. The way of determining them is different, too. Absolute ages are determined by radiometric methods, such as carbon-14 dating. These methods depend on radioactive decay. | D: absolute age. |
What organ eliminates solid wastes that remain after the digestion of food?
Here are the choices:
A. the large intestine
B. the appendix
C. the bladder
D. the spleen | The large intestine eliminates solid wastes that remain after the digestion of food. | A: the large intestine. |
What is the term for when a species no longer exists?
Here are the choices:
A. reproduction
B. survival
C. extinction
D. endangered | C: extinction. | |
What is the jelly-like material in which the contents of the cell are suspended?
Here are the choices:
A. cytosol
B. jam
C. cortisol
D. mitochondrial | The cytosol is the jelly-like material in which the contents of the cell are suspended. | A: cytosol. |
What is the release of energy in the form of high energy electromagnetic waves?
Here are the choices:
A. gamma emission
B. x-ray emission
C. normal emission
D. transient emission | Gamma emission is the release of energy in the form of high energy electromagnetic waves. | A: gamma emission. |
Today, new elements are usually named after famous scientists. the names of the elements can be cumbersome to write in full, especially when combined to form the names of compounds. therefore, each element name is abbreviated as a one- or two-letter chemical this?
Here are the choices:
A. shorthand
B. symbol
C. notation
D. title | Note Today, new elements are usually named after famous scientists. The names of the elements can be cumbersome to write in full, especially when combined to form the names of compounds. Therefore, each element name is abbreviated as a one- or two-letter chemical symbol. By convention, the first letter of a chemical symbol is a capital letter, while the second letter (if there is one) is a lowercase letter. The first letter of the symbol is usually the first letter of the element’s name, while the second letter is some other letter from the name. Some elements have symbols that derive from earlier, mostly Latin names, so the symbols may not contain any letters from the English name. Table 2.3 "Element Names and Symbols" lists the names and symbols of some of the most familiar elements. Table 2.3 Element Names and Symbols. | B: symbol. |
An infection may be intracellular or extracellular, depending on this?
Here are the choices:
A. bacteria
B. microbes
C. pathogen
D. pollen | 22.3 Magnetic Fields and Magnetic Field Lines • Magnetic fields can be pictorially represented by magnetic field lines, the properties of which are as follows: 1. The field is tangent to the magnetic field line. Field strength is proportional to the line density. Field lines cannot cross. Field lines are continuous loops. | C: pathogen. |
Like all tetrapods except birds and mammals, frogs possess a heart with what structure?
Here are the choices:
A. One Chamber
B. three chambers
C. four chambers
D. eight chambers | Adult frogs are characterized by long hind legs, a short body, webbed finger-like parts, and the lack of a tail. They also have a three-chambered heart, as do all tetrapods except birds and mammals. Most frogs live part of the time in water and part of the time on land. They move easily on land by jumping or climbing. To become great jumpers, frogs evolved long hind legs and long ankle bones. They also have a short backbone with only ten vertebrae. Frog and toad skin hangs loosely on the body, and skin texture can be smooth, warty, or folded. | B: three chambers. |
Energy is the capacity to do work or to produce what?
Here are the choices:
A. heat
B. vibration
C. light
D. humidity | Energy is the capacity to do work or to produce heat. | A: heat. |
In mammals, sound waves are collected by the external, cartilaginous part of the ear called the pinna, then travel through the auditory canal and cause vibration of the thin diaphragm called the tympanum or this?
Here are the choices:
A. microphone drum
B. ear drum
C. head drum
D. speaker drum | Reception of Sound In mammals, sound waves are collected by the external, cartilaginous part of the ear called the pinna, then travel through the auditory canal and cause vibration of the thin diaphragm called the tympanum or ear drum, the innermost part of the outer ear (illustrated in Figure 36.13). Interior to the tympanum is the middle ear. The middle ear holds three small bones called the ossicles, which transfer energy from the moving tympanum to the inner ear. The three ossicles are the malleus (also known as the hammer), the incus (the anvil), and stapes (the stirrup). The aptly named stapes looks very much like a stirrup. The three ossicles are unique to mammals, and each plays a role in hearing. The malleus attaches at three points to the interior surface of the tympanic membrane. The incus attaches the malleus to the stapes. In humans, the stapes is not long enough to reach the tympanum. If we did not have the malleus and the incus, then the vibrations of the tympanum would never reach the inner ear. These bones also function to collect force and amplify sounds. The ear ossicles are homologous to bones in a fish mouth: the bones that support gills in fish are thought to be adapted for use in the vertebrate ear over evolutionary time. Many animals (frogs, reptiles, and birds, for example) use the stapes of the middle ear to transmit vibrations to the middle ear. | B: ear drum. |
Unlike ionic compounds, covalent compounds do not have freely moving what?
Here are the choices:
A. electrons
B. Nuclei.
C. neutrons
D. atoms | Unlike ionic compounds, covalent compounds do not have freely moving electrons, so they cannot conduct electricity. | A: electrons. |
How do seed plants benefit from herbivores?
Here are the choices:
A. rainfall of seeds
B. consumption of seeds
C. dispersal of seeds
D. radiation of seeds | Herbivory has been used by seed plants for their own benefit in a display of mutualistic relationships. The dispersal of fruit by animals is the most striking example. The plant offers to the herbivore a nutritious source of food in return for spreading the plant’s genetic material to a wider area. An extreme example of collaboration between an animal and a plant is the case of acacia trees and ants. The trees support the insects with shelter and food. In return, ants discourage herbivores, both invertebrates and vertebrates, by stinging and attacking leaf-eating insects. | C: dispersal of seeds. |
What is the process in which cells make proteins called?
Here are the choices:
A. light synthesis
B. factor synthesis
C. protein synthesis
D. gas synthesis | The process in which cells make proteins is called protein synthesis . It actually consists of two processes: transcription and translation . Transcription takes place in the nucleus. It uses DNA as a template to make an RNA molecule. RNA then leaves the nucleus and goes to a ribosome in the cytoplasm, where translation occurs. Translation reads the genetic code in mRNA and makes a protein. | C: protein synthesis. |
How do you decrease errors in an experiment?
Here are the choices:
A. write about it
B. decrease measurements
C. take many measurements
D. ask God | Scientists make many measurements during experiments. Humans and equipment can make mistakes. Errors are often unavoidable. This is called experimental error . Errors may be due to the equipment being used. In this case, the numbers may be always skewed in one direction. For example, a scale may always measure one-half of an ounce high. People can also make errors. A measurement may not be made precisely. For example, a stopwatch may be stopped too soon or too late. But probably not always in the same direction. To correct for this, many measurements are taken. The measurements are then averaged. Experiments always have a margin of error associated with them. | C: take many measurements. |
What term describes scientists who debate the origin of the earliest plants?
Here are the choices:
A. protobotanists
B. archaebotanists
C. paleobotanists
D. specialists | Evolution of Angiosperms Undisputed fossil records place the massive appearance and diversification of angiosperms in the middle to late Mesozoic era. Angiosperms (“seed in a vessel”) produce a flower containing male and/or female reproductive structures. Fossil evidence (Figure 26.6) indicates that flowering plants first appeared in the Lower Cretaceous, about 125 million years ago, and were rapidly diversifying by the Middle Cretaceous, about 100 million years ago. Earlier traces of angiosperms are scarce. Fossilized pollen recovered from Jurassic geological material has been attributed to angiosperms. A few early Cretaceous rocks show clear imprints of leaves resembling angiosperm leaves. By the mid-Cretaceous, a staggering number of diverse flowering plants crowd the fossil record. The same geological period is also marked by the appearance of many modern groups of insects, including pollinating insects that played a key role in ecology and the evolution of flowering plants. Although several hypotheses have been offered to explain this sudden profusion and variety of flowering plants, none have garnered the consensus of paleobotanists (scientists who study ancient plants). New data in comparative genomics and paleobotany have, however, shed some light on the evolution of angiosperms. Rather than being derived from gymnosperms, angiosperms form a sister clade (a species and its descendents) that developed in parallel with the gymnosperms. The two innovative structures of flowers and fruit represent an improved reproductive strategy that served to protect the embryo, while increasing genetic variability and range. Paleobotanists debate whether angiosperms evolved from small woody bushes, or were basal angiosperms related to tropical grasses. Both views draw support from cladistics studies, and the so-called woody magnoliid hypothesis—which proposes that the early ancestors of angiosperms were shrubs—also offers molecular biological evidence. | C: paleobotanists. |
What anatomical system is made up of neurons and glia?
Here are the choices:
A. nervous system
B. digestive system
C. reproductive system
D. lymphatic system | CHAPTER SUMMARY 35.1 Neurons and Glial Cells The nervous system is made up of neurons and glia. Neurons are specialized cells that are capable of sending electrical as well as chemical signals. Most neurons contain dendrites, which receive these signals, and axons that send signals to other neurons or tissues. There are four main types of neurons: unipolar, bipolar, multipolar, and pseudounipolar neurons. Glia are non-neuronal cells in the nervous system that support neuronal development and signaling. There are several types of glia that serve different functions. | A: nervous system. |
What term describes the overall ability of an animal to survive and produce offspring?
Here are the choices:
A. fitness
B. change
C. evolution
D. abilities | Animal communication, like most other animal behaviors, increases the ability to survive and have offspring. This is known as fitness. Communication increases fitness by helping animals find food, defend themselves from predators, mate, and care for offspring. | A: fitness. |
Production of abnormal white blood cells occurs in what cancer, which is the most common form in children?
Here are the choices:
A. Breast
B. Bone
C. Brain
D. leukemia | Cancer can also be found in children. But childhood cancer is rare. Leukemia is the main type of cancer in children. It makes up about one third of all childhood cancers. It happens when the body makes abnormal white blood cells. | D: leukemia. |
How is the energy of an atomic orbital affected as the principal quantum number increases?
Here are the choices:
A. it decreases
B. it increases
C. It triples
D. It doubles | Orbital Energies and Atomic Structure The energy of atomic orbitals increases as the principal quantum number, n, increases. In any atom with two or more electrons, the repulsion between the electrons makes energies of subshells with different values of l differ so that the energy of the orbitals increases within a shell in the order s < p < d < f. Figure 6.25 depicts how these two trends in increasing energy relate. The 1s orbital at the bottom of the diagram is the orbital with electrons of lowest energy. The energy increases as we move up to the 2s and then 2p, 3s, and 3p orbitals, showing that the increasing n value has more influence on energy than the increasing l value for small atoms. However, this pattern does not hold for larger atoms. The 3d orbital is higher in energy than the 4s orbital. Such overlaps continue to occur frequently as we move up the chart. | B: it increases. |
During the typical human female ovulation cycles, how many eggs are released?
Here are the choices:
A. one
B. two
C. three
D. four | The Zygote Recall that at the point of fertilization, the oocyte has not yet completed meiosis; all secondary oocytes remain arrested in metaphase of meiosis II until fertilization. Only upon fertilization does the oocyte complete meiosis. The unneeded complement of genetic material that results is stored in a second polar body that is eventually ejected. At this moment, the oocyte has become an ovum, the female haploid gamete. The two haploid nuclei derived from the sperm and oocyte and contained within the egg are referred to as pronuclei. They decondense, expand, and replicate their DNA in preparation for mitosis. The pronuclei then migrate toward each other, their nuclear envelopes disintegrate, and the male- and femalederived genetic material intermingles. This step completes the process of fertilization and results in a single-celled diploid zygote with all the genetic instructions it needs to develop into a human. Most of the time, a woman releases a single egg during an ovulation cycle. However, in approximately 1 percent of ovulation cycles, two eggs are released and both are fertilized. Two zygotes form, implant, and develop, resulting in the. | A: one. |
Spores are the basic reproductive units of what organism?
Here are the choices:
A. tropical plants
B. fungi
C. mushrooms
D. yeast | Specialized structures for reproduction: One example is a fruiting body. Just like a fruit is involved in the reproduction of a fruiting plant, a fruiting body is involved in the reproduction of a fungus. A mushroom is a fruiting body , which is the part of the fungus that produces spores ( Figure below ). The spores are the basic reproductive units of fungi. The mycelium remains hidden until it develops one or more fruiting bodies. | B: fungi. |
During diastole, what happens to the elastic walls of the arteries?
Here are the choices:
A. they snap back
B. they become hardened
C. they evolve
D. they expand | A: they snap back. | |
Blood pressure is significantly affected by what physical force?
Here are the choices:
A. volume
B. density
C. mass
D. gravity | D: gravity. | |
An electormagnet is a piece of iron inside a?
Here are the choices:
A. copper core
B. solenoid
C. tunnel
D. reactor | An electormagnet is a piece of iron inside a solenoid. | B: solenoid. |
What term describes motion that repeats itself at regular time intervals, such as exhibited by a vibrating guitar string?
Here are the choices:
A. specific speed
B. periodic motion
C. apparent motion
D. gravitational pull | When you pluck a guitar string, the resulting sound has a steady tone and lasts a long time. Each successive vibration of the string takes the same time as the previous one. We define periodic motion to be a motion that repeats itself at regular time intervals, such as exhibited by the guitar string or by an object on a spring moving up and down. The time to complete one oscillation remains constant and is called the period T . Its units are usually seconds, but may be any convenient unit of time. The word period refers to the time for some event whether repetitive or not; but we shall be primarily interested in periodic motion, which is by definition repetitive. A concept closely related to period is the frequency of an event. For example, if you get a paycheck twice a month, the frequency of payment is two per month and the period between checks is half a month. Frequency f is defined to be the number of events per unit time. For periodic motion, frequency is the number of oscillations per unit time. The relationship between frequency and period is. | B: periodic motion. |
What form do biofuels take that makes them very useful?
Here are the choices:
A. liquid
B. chemical
C. solid
D. crystals | Biofuels are useful because they are liquid. Biofuels can go into a gas tank unlike many other types of alternative energy. | A: liquid. |
Most of food's chemical energy ultimately comes from what source?
Here are the choices:
A. sunlight
B. air
C. minerals
D. plants | Living things must have chemical energy from food to power life processes. Most of the chemical energy in food comes ultimately from the energy in sunlight. | A: sunlight. |
The northern spotted owl and the mexican spotted owl inhabit geographically separate locations with different climates and ecosystems. the owl is an example of?
Here are the choices:
A. symbiotic species
B. parallel evolution
C. biodiversity
D. allopatric speciation | Figure 18.12 The northern spotted owl and the Mexican spotted owl inhabit geographically separate locations with different climates and ecosystems. The owl is an example of allopatric speciation. (credit "northern spotted owl": modification of work by John and Karen Hollingsworth; credit "Mexican spotted owl": modification of work by Bill Radke). | D: allopatric speciation. |
Human actions such as plowing, logging, construction and other actions contribute to what kind of erosion?
Here are the choices:
A. flooding
B. wind erosion
C. weathering
D. soil erosion | Many human actions make it easier for wind and water to carry away soil. They include plowing, logging, construction, and even some types of recreation. | D: soil erosion. |
Why does the fish odour diminish when you put lemon juice over cooked fish?
Here are the choices:
A. due to oxidation
B. due to acidification
C. due to neutralization
D. due to evaporation | Chemistry in Everyday Life Culinary Aspects of Chemistry Cooking is essentially synthetic chemistry that happens to be safe to eat. There are a number of examples of acid-base chemistry in the culinary world. One example is the use of baking soda, or sodium bicarbonate in baking. NaHCO3 is a base. When it reacts with an acid such as lemon juice, buttermilk, or sour cream in a batter, bubbles of carbon dioxide gas are formed from decomposition of the resulting carbonic acid, and the batter “rises. ” Baking powder is a combination of sodium bicarbonate, and one or more acid salts that react when the two chemicals come in contact with water in the batter. Many people like to put lemon juice or vinegar, both of which are acids, on cooked fish (Figure 14.15). It turns out that fish have volatile amines (bases) in their systems, which are neutralized by the acids to yield involatile ammonium salts. This reduces the odor of the fish, and also adds a “sour” taste that we seem to enjoy. | C: due to neutralization. |
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