question
stringlengths 14
399
| distractor3
stringlengths 1
63
| distractor1
stringlengths 1
57
| distractor2
stringlengths 1
62
| correct_answer
stringlengths 1
67
| support
stringlengths 0
3.56k
|
|---|---|---|---|---|---|
What is considered to be the control center for homeostatic mechanisms? | adrenal cortex | thyroid | hippocampus | hypothalamus | The Hypothalamus The hypothalamus is the control center for many homeostatic mechanisms. It regulates both autonomic function and endocrine function. The roles it plays in the pupillary reflexes demonstrates the importance of this control center. The optic nerve projects primarily to the thalamus, which is the necessary relay to the occipital cortex for conscious visual perception. Another projection of the optic nerve, however, goes to the hypothalamus. The hypothalamus then uses this visual system input to drive the pupillary reflexes. If the retina is activated by high levels of light, the hypothalamus stimulates the parasympathetic response. If the optic nerve message shows that low levels of light are falling on the retina, the hypothalamus activates the sympathetic response. Output from the hypothalamus follows two main tracts, the dorsal longitudinal fasciculus and the medial forebrain bundle (Figure 15.11). Along these two tracts, the hypothalamus can influence the Eddinger–Westphal nucleus of the oculomotor complex or the lateral horns of the thoracic spinal cord. |
What molecules with a nitrogen base are the basic components of nucleic acids? | nuclides | sporozoans | enzymes | nucleiotides | The basic components of nucleic acids are nucleotides. A nucleotide is a molecule that contains a five-carbon sugar, a phosphate group, and a nitrogen containing base. The five-carbon sugar is either ribose, in the case of RNA, or deoxyribose, in the case of DNA. The only difference between the two molecules is the presence of a hydroxyl group attached to one member of the carbon ring in RNA. In DNA, that same carbon atom is attached only to a hydrogen atom (see Figure below ). Note that in drawing the structure of organic molecules, the single hydrogen atoms are not shown in the structure but are understood to be attached at each carbon point unless another molecule is shown. |
What were the first vertebrates to evolve? | shark | snail | trees | fish | Fish were the first vertebrates to evolve. The earliest fish lived in the water, and modern fish are still aquatic. |
What is defined as the rate of energy transferred? | pressure | charge | capacity | power | gravitational potential energy. Making Connections: Power Power is defined as the rate of energy transferred, or E / t . Fluid flow involves several types of power. Each type of power is identified with a specific type of energy being expended or changed in form. |
The cochlea and vestibul make up what part of the ear? | outer | middle | upper | inner | Figure 14.5 Structures of the Ear The external ear contains the auricle, ear canal, and tympanic membrane. The middle ear contains the ossicles and is connected to the pharynx by the Eustachian tube. The inner ear contains the cochlea and vestibule, which are responsible for audition and equilibrium, respectively. |
An individual with the appropriate number of what for their species is called euploid; abnormalities in this number include trisomy and monosomy? | genes | ribosomes | neutrons | chromosomes | Aneuploidy An individual with the appropriate number of chromosomes for their species is called euploid; in humans, euploidy corresponds to 22 pairs of autosomes and one pair of sex chromosomes. An individual with an error in chromosome number is described as aneuploid, a term that includes monosomy (loss of one chromosome) or trisomy (gain of an extraneous chromosome). Monosomic human zygotes missing any one copy of an autosome invariably fail to develop to birth because they lack essential genes. This underscores the importance of “gene dosage” in humans. Most autosomal trisomies also fail to develop to birth; however, duplications of some of the smaller chromosomes (13, 15, 18, 21, or 22) can result in offspring that survive for several weeks to many years. Trisomic individuals suffer from a different type of genetic imbalance: an excess in gene dose. Individuals with an extra chromosome may synthesize an abundance of the gene products encoded by that chromosome. This extra dose (150 percent) of specific genes can lead to a number of functional challenges and often precludes development. The most common trisomy among viable births is that of chromosome 21, which corresponds to Down Syndrome. Individuals with this inherited disorder are characterized by short stature and stunted digits, facial distinctions that include a broad skull and large tongue, and significant developmental delays. The incidence of Down syndrome is correlated with maternal age; older women are more likely to become pregnant with fetuses carrying the trisomy 21 genotype (Figure 13.7). |
A, t, g, and c pairs are associated with what substance that is important in genetics? | blood | plasma | bacteria | dna | Only certain types of base pairing are allowed. For example, a certain purine can only pair with a certain pyrimidine. This means A can pair with T, and G can pair with C, as shown in Figure 3.33. This is known as the base complementary rule. In other words, the DNA strands are complementary to each other. If the sequence of one strand is AATTGGCC, the complementary strand would have the sequence TTAACCGG. During DNA replication, each strand is copied, resulting in a daughter DNA double helix containing one parental DNA strand and a newly synthesized strand. |
What female flower structure, which is part of the pistil, receives the pollen grains and passes them to the ovary? | ovary | sepal | style | stigma | Flowers are the reproductive organs of plants. Each pea plant flower has both male and female parts. The anther is part of the stamen, the male structure that produces male gametes (pollen). The stigma is part of the pistil, the female structure that produces female gametes and guides the pollen grains to them. The stigma receives the pollen grains and passes them to the ovary, which contains female gametes. |
What is used by sensitive systems to detect even low levels of radiation? | ions | electrons | radars | crystals | Measurement of exposure to radioactivity is important for anyone who deals with radioactive materials on a regular basis. Perhaps the simplest device is a personal dosimeter – a film badge that will fog up when exposed to radiation. The amount of fogging is proportional to the amount of radiation present. These devices are not very sensitive to low levels of radiation. More sensitive systems use crystals that respond in some way to radioactivity by registering the number of emissions in a given time. These systems tend to be more sensitive and more reliable than film badges. |
What is the leading cause of skin cancer? | smoking | artificial light | dehydration | sunlight | Forms of radiation that cause cancer include ultraviolet (UV) radiation and radon ( Figure below ). UV radiation is part of sunlight. It is the leading cause of skin cancer. Radon is a natural radioactive gas that seeps into buildings from the ground. It can cause lung cancer. |
What is cholera? | glucose | protein | energy | bacteria | Unsafe drinking water causes 88% of diseases worldwide. In many nations, these diseases are the leading cause of death in children under the age of five. More than 14,000 people die every day from such diseases. Cholera is caused by bacteria. A person gets guinea worm from drinking the guinea worm larvae ( Figure below ). The cholera bacteria and guinea worms are pathogens. |
Which element has atomic number 87? | barium | iron | argon | francium | Francium has an atomic number of 87. Write the chemical equation for the alpha particle emission of 212Fr. What is the daughter isotope?. |
What is the basic chemical building block of matter; it is the simplest chemical substance? | hydrogen | atoms | helium | element | An element is the basic chemical building block of matter; it is the simplest chemical substance. |
What do you call the lower layer of soil that is permanently frozen, and is a frequent feature of tundra? | solid | solvent | underfoot | permafrost | Polar climates are found near the North and South Poles. They also occur on high mountains at lower latitudes. The summers are very cool, and the winters are frigid. Precipitation is very low because it’s so cold. The growing season is very short. Tundra prefers areas of permafrost. Permafrost is a lower layer of soil that is permanently frozen. Tundra also refers to a treeless plain with small plants. You can see examples of polar climates pictured below. |
Modern taxonomy is based on many hypotheses' of the evolutionary history of organisms, known as this? | pathogeny | algorithm | cladistic | phylogeny | 22.0.6 Phylogeny, Cladistics & Cladogram Modern taxonomy is based on many hypotheses' of the evolutionary history of organisms, known as phylogeny. As with the Scientific Method, scientists develop a hypothesis on the history of an animal and utilise modern science and technology to prove the phylogeny. Cladistics is a classification system which is based on phylogeny. Expanding on phylogeny, cladistics is based on the assumption that each group of related species has one common ancestor and would therefore retain some ancestral characteristics. Moreover, as these related species evolve and diverge from their common ancestor, they would develop unique characteristics. Such characteristics are known as derived characteristics The principles of phylogeny and cladistics can be expressed visually as a cladogram, a branching diagram which acts as a family (phylogenetic) tree for similar species. A cladogram can also be used to test alternative hypotheses for an animal's phylogeny. In order to determine the most likely cladogram, the derived characteristics of similar species are matched and analysed. |
What method plays a role in determining the approximate age of the earth and makes use of uranium? | waste dating | fuel dating | carbon dating | radioactive dating | Things Great and Small Nuclear Decay Helps Explain Earth’s Hot Interior A puzzle created by radioactive dating of rocks is resolved by radioactive heating of Earth’s interior. This intriguing story is another example of how small-scale physics can explain large-scale phenomena. Radioactive dating plays a role in determining the approximate age of the Earth. The oldest rocks on Earth solidified about 3.5×10 9 years ago—a number determined by uranium-238 dating. These rocks could only have solidified once the surface of the Earth had cooled sufficiently. The temperature of the Earth at formation can be estimated based on gravitational potential energy of the assemblage of pieces being converted to thermal energy. Using heat transfer concepts discussed in Thermodynamics it is then possible to calculate how long it would take for the surface to cool to rock9 9 formation temperatures. The result is about 10 years. The first rocks formed have been solid for 3.5×10 years, so that 9 the age of the Earth is approximately 4.5×10 years. There is a large body of other types of evidence (both Earth-bound and solar system characteristics are used) that supports this age. The puzzle is that, given its age and initial temperature, the center of the Earth should be much cooler than it is today (see Figure 31.26). |
The study of energy and energy transfer involving physical matter is what? | nuclear energy | geology | biochemistry | thermodynamics | Energy Thermodynamics refers to the study of energy and energy transfer involving physical matter. The matter relevant to a particular case of energy transfer is called a system, and everything outside of that matter is called the surroundings. For instance, when heating a pot of water on the stove, the system includes the stove, the pot, and the water. Energy is transferred within the system (between the stove, pot, and water). There are two types of systems: open and closed. In an open system, energy can be exchanged with its surroundings. The stovetop system is open because heat can be lost to the air. A closed system cannot exchange energy with its surroundings. Biological organisms are open systems. Energy is exchanged between them and their surroundings as they use energy from the sun to perform photosynthesis or consume energy-storing molecules and release energy to the environment by doing work and releasing heat. Like all things in the physical world, energy is subject to physical laws. The laws of thermodynamics govern the transfer of energy in and among all systems in the universe. In general, energy is defined as the ability to do work, or to create some kind of change. Energy exists in different forms. For example, electrical energy, light energy, and heat energy are all different types of energy. To appreciate the way energy flows into and out of biological systems, it is important to understand two of the physical laws that govern energy. |
In a science lab, what device would you use to measure the volume of a liquid? | yardstick | anemometer | Richter scale | graduated cylinder | Measuring devices must be used correctly to get accurate measurements. Figure below shows the correct way to use a graduated cylinder to measure the volume of a liquid. |
Human blood has a buffering system to minimize extreme changes in what? | ions | sodium level | calcium | ph | Buffers work well only for limited amounts of added strong acid or base. Once either solute is all reacted, the solution is no longer a buffer, and rapid changes in pH may occur. We say that a buffer has a certain capacity. Buffers that have more solute dissolved in them to start with have larger capacities, as might be expected. Human blood has a buffering system to minimize extreme changes in pH. One buffer in blood is based on the presence of HCO3− and H2CO3 [H2CO3 is another way to write CO2(aq)]. With this buffer present, even if some stomach acid were to find its way directly into the bloodstream, the change in the pH of blood would be minimal. Inside many of the body’s cells, there is a buffering system based on phosphate ions. |
The unpaired ethmoid bone is located where within the central skull? | at the fold | at the top | at the point | at the midline | Figure 7.12 Ethmoid Bone The unpaired ethmoid bone is located at the midline within the central skull. It has an upward projection, the crista galli, and a downward projection, the perpendicular plate, which forms the upper nasal septum. The cribriform plates form both the roof of the nasal cavity and a portion of the anterior cranial fossa floor. The lateral sides of the ethmoid bone form the lateral walls of the upper nasal cavity, part of the medial orbit wall, and give rise to the superior and middle nasal conchae. The ethmoid bone also contains the ethmoid air cells. |
A statement is considered what if it is open to being falsified? | untrue | valid | premature | hypothesis | At a given temperature, individual particles of a substance have a range of kinetic energies. |
Name the physical phenomenon of the ocean that has a significant impact on both ocean life and human life. | el pino | las nino | el nieto | el nino | 2.11 EL NIÑO Introduction: Consider the physical dynamics of the oceans. WOW! That sounds like trouble! What do “physical dynamics” mean? It sounds hard and boring. Not to fear. Though it may be boring to some of you, it should not be too hard. What is meant by “physical dynamics”? Physical refers to something that is observable and measurable. Dynamics are the way things work. So, the physical dynamics of the ocean refer to the measurable, observable ways that the ocean works. Not so bad, right? The physical dynamics of the ocean include things like tides, temperature, wave action, ocean currents, salinity (concentration of salt), and ocean depth. The physical dynamics of the ocean are all abiotic factors. It should not be surprising to you that the abiotic ocean factors (the physical dynamics) affect the ocean’s biotic factors, i. the organisms that live in and around the ocean. We often hear the term "El Nino" but few of us really understand what it means or how it affects us. El Nino is a physical phenomenon of the ocean that has a significant impact on both ocean life and human life. In this assignment you will describe El Nino and its impact on the Earth’s biosphere. Assignment: Using the Internet, find information related to El Nino. There are a multitude of Internet sources; you will probably find more information than you can possibly use. Using the information from at least THREE different Internet sources, write a THREE page, type written, double spaced essay that answers the following FOUR questions: 1. What are oceans currents? What are tides? Describe the ocean currents and tides, what they are; what causes them, where they normally flow, etc… 2. What is El Nino? Describe what it is and what causes it. How does it affect ocean currents and tides? Water temperature? Other abiotic factors? 3. |
What is the process by which large particles, such as cells, are taken in by a cell? | mitosis | active transport | diffusion | phagocytosis | Phagocytosis is the process by which large particles, such as cells, are taken in by a cell. For example, when microorganisms invade the human body, a type of white blood cell called a neutrophil removes the invader through this process, surrounding and engulfing the microorganism, which is then destroyed by the neutrophil (Figure 3.26). A variation of endocytosis is called pinocytosis. This literally means “cell drinking” and was named at a time when the assumption was that the cell was purposefully taking in extracellular fluid. In reality, this process takes in solutes that the cell needs from the extracellular fluid (Figure 3.26). A targeted variation of endocytosis employs binding proteins in the plasma membrane that are specific for certain substances (Figure 3.26). The particles bind to the proteins and the plasma membrane invaginates, bringing the substance and the proteins into the cell. If passage across the membrane of the target of receptor-mediated endocytosis is ineffective, it will not be removed from the tissue fluids or blood. Instead, it will stay in those fluids and increase in concentration. Some human diseases are caused by a failure of receptor-mediated endocytosis. For example, the form of cholesterol termed low-density lipoprotein or LDL (also referred to as “bad” cholesterol) is removed from the blood by receptormediated endocytosis. In the human genetic disease familial hypercholesterolemia, the LDL receptors are defective or missing entirely. People with this condition have life-threatening levels of cholesterol in their blood, because their cells cannot clear the chemical from their blood. |
Budding is a form of what type of reproduction in tunicates? | microscopic | sexual | nuclear | asexual | As larvae, tunicates can swim freely to find food. As adults, tunicates lack a post-anal tail and notochord, and they can no longer swim. Instead, they remain in one place and are filter feeders. Tunicates can reproduce both sexually and asexually. The same adults produce sperm and eggs. However, fertilization always involves gametes from different parents. Asexual reproduction is by budding. |
Ocean water releases dissolved carbon dioxide into the atmosphere when what happens to the temperature? | Goes Down | Later | Drops | it rises | Ocean water releases dissolved carbon dioxide into the atmosphere when water temperature rises. |
The physical sciences can be divided into physics and what other science? | phsycology | biology | astrology | chemistry | Physical science, in turn, can be divided into chemistry and physics. Chemistry is the study of matter and energy at the scale of atoms and molecules. For example, the synthetic fibers in the swimmer’s suit were created in labs by chemists. Physics is the study of matter and energy at all scales—from the tiniest particles of matter to the entire universe. Knowledge of several important physics concepts—such as motion and forces—contributed to the design of the swimmer’s suit. |
What do you call trees that lose their leaves in the fall and grow new ones in the spring? | coniferous | perennial | fibrous | deciduous | Humid continental climates are found between 40° and 60° north latitude. The northeastern U. S. has this type of climate. Summers are warm to hot, and winters are cold. Precipitation is moderate, and it falls year round. Deciduous trees grow in this climate ( Figure below ). They lose their leaves in the fall and grow new ones in the spring. |
In which organ of the body does gluconeogenesis primarily take place? | heart | kidney | spleen | liver | Gluconeogenesis Gluconeogenesis is the synthesis of new glucose molecules from pyruvate, lactate, glycerol, or the amino acids alanine or glutamine. This process takes place primarily in the liver during periods of low glucose, that is, under conditions of fasting, starvation, and low carbohydrate diets. So, the question can be raised as to why the body would create something it has just spent a fair amount of effort to break down? Certain key organs, including the brain, can use only glucose as an energy source; therefore, it is essential that the body maintain a minimum blood glucose concentration. When the blood glucose concentration falls below that certain point, new glucose is synthesized by the liver to raise the blood concentration to normal. Gluconeogenesis is not simply the reverse of glycolysis. There are some important differences (Figure 24.10). Pyruvate is a common starting material for gluconeogenesis. First, the pyruvate is converted into oxaloacetate. Oxaloacetate then serves as a substrate for the enzyme phosphoenolpyruvate carboxykinase (PEPCK), which transforms oxaloacetate into phosphoenolpyruvate (PEP). From this step, gluconeogenesis is nearly the reverse of glycolysis. PEP is converted back into 2-phosphoglycerate, which is converted into 3-phosphoglycerate. Then, 3-phosphoglycerate is converted into 1,3 bisphosphoglycerate and then into glyceraldehyde-3-phosphate. Two molecules of glyceraldehyde-3-phosphate then combine to form fructose-1-6-bisphosphate, which is converted into fructose 6-phosphate and then into glucose-6-phosphate. Finally, a series of reactions generates glucose itself. In gluconeogenesis (as compared to glycolysis), the enzyme hexokinase is replaced by glucose-6-phosphatase, and the enzyme phosphofructokinase-1 is replaced by fructose-1,6-bisphosphatase. This helps the cell to regulate glycolysis and gluconeogenesis independently of each other. As will be discussed as part of lipolysis, fats can be broken down into glycerol, which can be phosphorylated to form dihydroxyacetone phosphate or DHAP. DHAP can either enter the glycolytic pathway or be used by the liver as a substrate for gluconeogenesis. |
What kind of structure contains the largest known single cell? | sperm | proteins | Ovaries | egg | The cells you have learned about so far are much smaller than the period at the end of this sentence, so they are normally measured on a very small scale. The smallest prokaryotic cell currently known has a diameter of only 400 nm. Eukaryotic cells normally range between 1– 100µm in diameter. The mouse cells in Figure above are about 10 µm in diameter. One exception, however, is eggs . Eggs contain the largest known single cell, and the ostrich egg is the largest of them all. The ostrich egg in Figure above is over 10,000 times larger than the mouse cell. |
While enzymatic hydrolysis proceeds, peristalsis moves the mixture of chyme and digestive juices along what? | large intestine | esophagus | stomach | small intestine | |
What is the most common type of muscle in the human body? | digestive | fetal | internal | skeletal | Muscle tissue that is attached to bone is skeletal muscle . Whether you are blinking your eyes or running a marathon, you are using skeletal muscle. Contractions of skeletal muscle are voluntary, or under conscious control. When skeletal muscle contracts, bones move. Skeletal muscle is the most common type of muscle in the human body. |
The last two stages of aerobic respiration require what? | sulfur | water | carbon | oxygen | The last two stages of aerobic respiration require oxygen. However, not all organisms live in places where there is a plentiful supply of oxygen. |
The rate of dissolving is influenced by surface area, stirring, and what else? | gravity | oxygen | density | temperature | The rate of dissolving is influenced by surface area, stirring, and temperature. |
What disease unique to humans and is caused by two variola viruses? | ebola | AIDS | diabetes | smallpox | A worldwide vaccination campaign by the World Health Organization led to the eradication of smallpox in 1979. Smallpox is a contagious disease unique to humans and is caused by two Variola viruses. The eradication of smallpox was possible because humans are the only carriers of the virus. To this day, smallpox is the only human infectious disease to have been completely eradicated from nature. Scientists are hoping to eradicate polio next. |
What is the average kinetic energy of particles of matter? | friction | momentum | magnetism | temperature | Temperature is the average kinetic energy of particles of matter. |
How can you prevent your ice cream from getting a sandy texture? | by adding salt | by using lowfat milk | by adding oil | by using fructose | Fructose, a sugar found in fruit, contains only carbon, oxygen, and hydrogen. It is used in ice cream to prevent a sandy texture. Complete combustion of 32.4 mg of fructose in oxygen produced 47.6 mg of CO2 and 19.4 mg of H2O. What is the empirical formula of fructose? 11. Coniine, the primary toxin in hemlock, contains only carbon, nitrogen, and hydrogen. When ingested, it causes paralysis and eventual death. Complete combustion of 28.7 mg of coniine produced 79.4 mg of CO2 and 34.4 mg of H2O. What is the empirical formula of the coniine? 12. Copper and tin alloys (bronzes) with a high arsenic content were presumably used by Bronze Age metallurgists because bronze produced from arsenic-rich ores had superior casting and working properties. The compositions of some representative bronzes of this type are as follows:. |
Plants can lose their leaves, flower, or break dormancy in response to a change in what? | averages | events | periods | seasons | Plants can respond to the change of season by losing their leaves, flowering, or breaking dormancy. |
What is the second highest mountain in the world, at over 28,000 feet? | everest | pikes peak | makalu | k2 | The Karakoram Range is part of the Himalaya Mountains. K2, pictured here, is the second highest mountain the world at over 28,000 feet. The number and height of mountains is impressive. |
What are the two classifications of natural resources? | recyclable and reversible | renewable and reusable | productive and nonrenewable | renewable and nonrenewable | From the human point of view, natural resources can be classified as renewable or nonrenewable. |
Maintaining a high metabolic rate takes a lot of what? | power | fuel | hydrogen | energy | Maintaining a high metabolic rate takes a lot of energy. The energy must come from food. Therefore, mammals need a nutritious and plentiful diet. The diets of mammals are diverse. Except for leaf litter and wood, almost any kind of organic matter may be eaten by mammals. Some mammals are strictly herbivores or strictly carnivores. However, most mammals will eat other foods if necessary. Some mammals are omnivores. They routinely eat a variety of both plant and animal foods. Most mammals also feed on a variety of other species. The few exceptions include koalas, which feed only on eucalyptus plants, and giant pandas, which feed only on bamboo. Types of mammalian diets and examples of mammals that eat them are given in Table below . How would you classify your own diet?. |
What is the photosynthesis factory of the plant? | genome | pistil | stamen | chloroplast | The chloroplast is the photosynthesis factory of the plant. |
The process that a plant increases in size is known as what? | harvest | fertilization | trend | growth | |
What are reversible physical changes in matter called? | transformations | chemical change | alterations | changes of state | Changes of state are physical changes in matter. They are reversible changes that do not change matter’s chemical makeup or chemical properties. For example, when fog changes to water vapor, it is still water and can change back to liquid water again. |
Compounds that form from two or more nonmetallic elements are called what? | hydrogen bonds | ionic bonds | valent bonds | covalent bonds | Compounds that form from two or more nonmetallic elements, such as carbon and hydrogen, are called covalent compounds . In a covalent compound, atoms of the different elements are held together in molecules by covalent bonds. These are chemical bonds in which atoms share valence electrons. The force of attraction between the shared electrons and the positive nuclei of both atoms holds the atoms together in the molecule. A molecule is the smallest particle of a covalent compound that still has the properties of the compound. |
The ability to maintain a stable internal temperature, despite the climate, is exhibited by members of what animal group? | reptiles | fish | parasites | mammals | Not really. Like all mammals, polar bears maintain a stable internal temperature. They do not need to stay warm by lying in the sun. This allows them to live in cold climates. |
What are substances that provide hydrogen ions (h+) and lower ph? | bases | proteins | nutrients | acids | Acids are substances that provide hydrogen ions (H+) and lower pH, whereas bases provide hydroxide ions (OH–) and raise pH. The stronger the acid, the more readily it donates H+. For example, hydrochloric acid and lemon juice are very acidic and readily give up H+ when added to water. Conversely, bases are those substances that readily donate OH–. The OH– ions combine with H+ to produce water, which raises a substance’s pH. Sodium hydroxide and many household cleaners are very alkaline and give up OH– rapidly when placed in water, thereby raising the pH. Most cells in our bodies operate within a very narrow window of the pH scale, typically ranging only from 7.2 to 7.6. If the pH of the body is outside of this range, the respiratory system malfunctions, as do other organs in the body. Cells no longer function properly, and proteins will break down. Deviation outside of the pH range can induce coma or even cause death. So how is it that we can ingest or inhale acidic or basic substances and not die? Buffers are the key. Buffers readily absorb excess H+ or OH–, keeping the pH of the body carefully maintained in the aforementioned narrow range. Carbon dioxide is part of a prominent buffer system in the human body; it keeps the pH within the proper range. This buffer system involves carbonic acid (H2CO3) and bicarbonate (HCO3–) anion. If too much H+ enters the body, bicarbonate will combine with the H+ to create carbonic acid and limit the decrease in pH. Likewise, if too much OH– is introduced into the system, carbonic acid will rapidly dissociate into bicarbonate and H+ ions. The H+ ions can combine with the OH– ions, limiting the increase in pH. While carbonic acid is an important product in this reaction, its presence is fleeting because the carbonic acid is released from the body as carbon dioxide gas each time we breathe. Without this buffer system, the pH in our bodies would fluctuate too much and we would fail to survive. |
What are mercury manometers often used to measure? | brain waves | weight | balance | blood pressure | Mercury manometers are often used to measure arterial blood pressure. An inflatable cuff is placed on the upper arm as shown in Figure 11.17. By squeezing the bulb, the person making the measurement exerts pressure, which is transmitted undiminished. |
What did rockets help launch into space during their beginning? | sensors | rovers | shuttles | satellites | One of the first uses of rockets in space was to launch satellites. A satellite is an object that orbits a larger object. An orbit is a circular or elliptical path around an object. Natural objects in orbit are called natural satellites. The Moon is a natural satellite. Human-made objects in orbit are called artificial satellites. |
What sound can be heard when sound waves bounce back from a hard object? | boom | loop | eerie | echo | Did you ever hear an echo of your own voice? An echo occurs when sound waves bounce back from a hard object. The man in Figure below is trying to create an echo by shouting toward a rock wall. When the sound waves strike the rock wall, they can’t pass through. Instead, they bounce back toward the man, and he hears an echo of his voice. An echo is just one example of how waves interact with matter. |
Robert merrifield developed the first synthetic approach for making what essential cell substances in the lab? | lipids | cells | acids | proteins | Cells in our bodies have an intricate mechanism for the manufacture of proteins. Humans have to use other techniques in order to synthesize the same proteins in a lab. The chemistry of peptide synthesis is complicated. Both active groups on an amino acid can react and the amino acid sequence must be a specific one in order for the protein to function. Robert Merrifield developed the first synthetic approach for making proteins in the lab, a manual approach which was lengthy and tedious (and, he won the Nobel Prize in Chemistry in 1984 for his work). Today however, automated systems can crank out a peptide in a very short period of time. |
Strangeness, charm, bottomness, and topness are properties of what subatomic particle? | molecules | pion | dark matter | quarks | ± symbols are the values for antiquarks. B is baryon number, S is strangeness, c is charm, b is bottomness, t is topness. Values are approximate, are not directly observable, and vary with model. |
What needs to happen to temperature to cause pressure to increase dramatically? | small increase | boiling point | no increase | large increase | The pressure increases dramatically due to large increase in temperature. |
Australopithecus afarensis is an ancestor of what primate? | gorillas | lemurs | orangutans | humans | Australopithecus afarensis is a human ancestor that lived about 3 million years ago. |
Organs that produce eggs and secrete estrogen are part of what system? | male reproductive system | circulatory system | digestive system | female reproductive system | one of two female reproductive organs that produces eggs and secretes estrogen. |
What are the most common types of compounds found on earth? | hydrogen-based compounds | sodium - based compounds | ionic compounds | carbon-based compounds | Cellulose is a compound found in plants. The chief component of cellulose is carbon. Cellulose is one of many carbon-based compounds that make up living things. In fact, carbon-based compounds are the most common type of compound on Earth. More than 90 percent of all known compounds contain carbon. Do you know why carbon is found in so many compounds? Read on to find out. |
Which planet is closest to the sun? | Venus | Earth | Jupiter | mercury | The four planets closest to the Sun - Mercury, Venus, Earth, and Mars - are the inner planets . They are similar to Earth. All are solid, dense, and rocky. None of the inner planets has rings. Compared to the outer planets, the inner planets are small. They have shorter orbits around the Sun and they spin more slowly. Venus spins backwards and spins the slowest of all the planets. |
What do you call it when adult fish of the same species come together in a group and release gametes into the water at the same time? | poaching | migration | schoaling | spawning | Nearly all fish reproduce sexually and have separate sexes. Fertilization is generally external, and most fish are oviparous. Many adults of the same species may come together in a group and release gametes into the water at the same time, which is called spawning. Fish hatch into larvae that are different from the adult form of the species. |
What happens to the volume of a gas as the kelvin temperature increases? | it continues | it decreases | it drops | it increases | The volume of a gas increases as the Kelvin temperature increases. |
If only one atom of a specific type is present what is not used? | subset | covalent bond | consonant | subscript | If only one atom of a specific type is present, no subscript is used. |
What are the earliest reptile genus named? | scolecophis | brachyophis | collorhabdium | hylonomus | Earliest Reptile: Hylonomus . The earliest known reptile is given the genus name Hylonomus . It was about 20 to 30 centimeters (8 to 12 inches) long, lived in swamps, and ate insects and other small invertebrates. |
What produces all the cells of the root and the root cap? | algal meristem | somatic meristem | interior meristem | apical meristem | |
What is the master gland of the endocrine system? | Thymus | Thyroid | Hypothyroid | pituitary gland | The hypothalamus is part of the brain and also secretes hormones, thus connecting the nervous and endocrine systems. The pituitary gland is the master gland of the endocrine system and controls other endocrine glands. Endocrine glands also include the thyroid gland, adrenal glands, pancreas, and gonads. |
The earth’s biomes are categorized into two major groups named what? | terrestrial and galactic | icelandic and aquatic | aquatic and galactic | terrestrial and aquatic | 44.3 | Terrestrial Biomes By the end of this section, you will be able to: • Identify the two major abiotic factors that determine terrestrial biomes • Recognize distinguishing characteristics of each of the eight major terrestrial biomes The Earth’s biomes are categorized into two major groups: terrestrial and aquatic. Terrestrial biomes are based on land, while aquatic biomes include both ocean and freshwater biomes. The eight major terrestrial biomes on Earth are each distinguished by characteristic temperatures and amount of precipitation. Comparing the annual totals of precipitation and fluctuations in precipitation from one biome to another provides clues as to the importance of abiotic factors in the distribution of biomes. Temperature variation on a daily and seasonal basis is also important for predicting the geographic distribution of the biome and the vegetation type in the biome. The distribution of these biomes shows that the same biome can occur in geographically distinct areas with similar climates (Figure 44.12). |
What does the thymus gland produce? | hormones | b cells | insulin | t cells | Organs of the lymphatic system include the tonsils, thymus gland and spleen. The thymus gland produces T cells or T-lymphocytes (see below) and the spleen and tonsils help in fighting infections. The spleen’s main function is to filter the blood. The spleen also detects viruses and bacteria and triggers the release of pathogen fighting cells. |
During which phase does dna replication occur in the cell cycle? | mitosis | resting | gap | synthesis | 9.2 | DNA Replication By the end of this section, you will be able to: • Explain the process of DNA replication • Explain the importance of telomerase to DNA replication • Describe mechanisms of DNA repair When a cell divides, it is important that each daughter cell receives an identical copy of the DNA. This is accomplished by the process of DNA replication. The replication of DNA occurs during the synthesis phase, or S phase, of the cell cycle, before the cell enters mitosis or meiosis. The elucidation of the structure of the double helix provided a hint as to how DNA is copied. Recall that adenine nucleotides pair with thymine nucleotides, and cytosine with guanine. This means that the two strands are complementary to each other. For example, a strand of DNA with a nucleotide sequence of AGTCATGA will have a complementary strand with the sequence TCAGTACT (Figure 9.8). |
What kind of interactions do polar substances experience? | monopole-monopole interactions | monopole-dipole interactions | axial interactions | dipole-dipole interactions | Substances that are polar experience dipole-dipole interactions. |
Which process is glycolysis in during cellular respiration? | enzymatic | aerobic | hydrolysis | anaerobic | Cellular respiration occurs in three stages: glycolysis, the Krebs cycle, and electron transport. Glycolysis is an anaerobic process. The other two stages are aerobic processes. |
Saturated hydrocarbons are given the general name of what? | lipids | enzymes | carbohydrates | alkanes | Saturated hydrocarbons are given the general name of alkanes. The name of specific alkanes always ends in –ane and has a prefix to indicate how many carbon atoms it has. |
In the cellular process of transcription, dna code is converted into what other kind of code? | fna | dpa | sna | rna | 3.4 Protein Synthesis DNA stores the information necessary for instructing the cell to perform all of its functions. Cells use the genetic code stored within DNA to build proteins, which ultimately determine the structure and function of the cell. This genetic code lies in the particular sequence of nucleotides that make up each gene along the DNA molecule. To “read” this code, the cell must perform two sequential steps. In the first step, transcription, the DNA code is converted into a RNA code. A molecule of messenger RNA that is complementary to a specific gene is synthesized in a process similar to DNA replication. The molecule of mRNA provides the code to synthesize a protein. In the process of translation, the mRNA attaches to a ribosome. Next, tRNA molecules shuttle the appropriate amino acids to the ribosome, one-by-one, coded by sequential triplet codons on the mRNA, until the protein is fully synthesized. When completed, the mRNA detaches from the ribosome, and the protein is released. Typically, multiple ribosomes attach to a single mRNA molecule at once such that multiple proteins can be manufactured from the mRNA concurrently. |
If a gyroscope is not spinning, it acquires angular momentum in the direction of what? | velocity | gravity | acceleration | torque | This same logic explains the behavior of gyroscopes. Figure 10.31 shows the two forces acting on a spinning gyroscope. The torque produced is perpendicular to the angular momentum, thus the direction of the torque is changed, but not its magnitude. The gyroscope precesses around a vertical axis, since the torque is always horizontal and perpendicular to L . If the gyroscope is not spinning, it acquires angular momentum in the direction of the torque ( L falling over just as we would expect. |
Which leukocytes are first to respond to bacterial infections? | microcytes | chemocytes | erythrocytes | neutrophils | 18.4 Leukocytes and Platelets Leukocytes function in body defenses. They squeeze out of the walls of blood vessels through emigration or diapedesis, then may move through tissue fluid or become attached to various organs where they fight against pathogenic organisms, diseased cells, or other threats to health. Granular leukocytes, which include neutrophils, eosinophils, and basophils, originate with myeloid stem cells, as do the agranular monocytes. The other agranular leukocytes, NK cells, B cells, and T cells, arise from the lymphoid stem cell line. The most abundant leukocytes are the neutrophils, which are first responders to infections, especially with bacteria. About 20–30 percent of all leukocytes are lymphocytes, which are critical to the body’s defense against specific threats. Leukemia and lymphoma are malignancies involving leukocytes. Platelets are fragments of cells known as megakaryocytes that dwell within the bone marrow. While many platelets are stored in the spleen, others enter the circulation and are essential for hemostasis; they also produce several growth factors important for repair and healing. |
What thin whip-like structures help prokaryotes move toward food or away from toxins? | antennae | sporangia | cilia | flagella | Most prokaryotes have one or more long, thin "whips" called flagella (flagellum, plural) . You can see flagella in Figure below . Flagella help prokaryotes move toward food or away from toxins. Each flagellum spins around a fixed base. This causes the cell to roll and tumble. |
What common process is used in the production of bread, cheese and alcoholic beverages? | oxidation | cloning | condensation | fermentation | agents of fermentation in the production of bread, cheeses, alcoholic beverages, and numerous other food preparations. Secondary metabolites of fungi are used in medicine as antibiotics and anticoagulants. Fungi are used in research as model organisms for the study of eukaryotic genetics and metabolism. |
Comprising 10 percent of the mass of the brain, what structure has varied functions that all point to a role in the motor system? | superior peduncle | medulla oblongata | cerebrum | cerebellum | 16.5 | The Coordination and Gait Exams By the end of this section, you will be able to: • Explain the relationship between the location of the cerebellum and its function in movement • Chart the major divisions of the cerebellum • List the major connections of the cerebellum • Describe the relationship of the cerebellum to axial and appendicular musculature • Explain the prevalent causes of cerebellar ataxia The role of the cerebellum is a subject of debate. There is an obvious connection to motor function based on the clinical implications of cerebellar damage. There is also strong evidence of the cerebellar role in procedural memory. The two are not incompatible; in fact, procedural memory is motor memory, such as learning to ride a bicycle. Significant work has been performed to describe the connections within the cerebellum that result in learning. A model for this learning is classical conditioning, as shown by the famous dogs from the physiologist Ivan Pavlov’s work. This classical conditioning, which can be related to motor learning, fits with the neural connections of the cerebellum. The cerebellum is 10 percent of the mass of the brain and has varied functions that all point to a role in the motor system. |
What is a segment of dna that carries a code for making a specific polypeptide chain called? | amino acid | a protein | nucleotide | a gene | Each particular organism contains many protein molecules that are specific to that organism. The particular base sequence of DNA is responsible for the production of all of the different proteins that are present in each and every living thing that has ever inhabited the Earth. How does that work? Cells use the unique sequence of DNA bases to decide which proteins to synthesize. A gene is a segment of DNA that carries a code for making a specific polypeptide chain. The cell essentially decodes the DNA in order to make whatever peptides and proteins are needed by that organism. |
Introduction of antigens into the body through immunization can confer what benefit? | sensitive immunity | active respiration | growth rate | active immunity | |
What part of the brain is largest in intelligent mammals? | cortex | thallus | manubrium | cerebrum | In intelligent mammals, such as primates, the cerebrum is larger compared to the rest of the brain. A larger cerebrum allows primates to develop higher levels of intelligence. Primates have the ability to learn new behaviors. They also engage in complex social interactions, such as fighting and play. |
What is the cause of most ocean waves? | Gravity | tides | Magnetic pull | winds | Most ocean waves are caused by winds. The size of a wave depends on how fast, how far, and how long the wind blows. Tsunamis are waves caused by earthquakes. |
What is the lowest layer of the atmosphere called? | asthenosphere | mesosphere | lithosphere | troposphere | Air movement takes place in the troposphere. This is the lowest layer of the atmosphere. Air moves because of differences in heating. These differences create convection currents and winds ( Figure below ). |
What is the biggest group of animals on the planet? | carnivores | herbivores | mammles | arthropods | How often do you think you see an arthropod? Well, have you ever looked up close at an ant? A spider? A fly? A moth? With over a million described species (and many more yet to be described) in the phylum containing arthropods, chances are, you encounter one of these organisms every day, without even leaving your house. Arthropods are a very diverse group of animals. In fact, they are the biggest group of animals on the planet, with upwards of 5 million distinct species. |
The presence of solute particles blocks some of the ability for liquid particles to do what? | dissolve | melt | fuse | evaporate | The presence of solute particles blocks some of the ability for liquid particles to evaporate. Thus, solutions of solid solutes typically have a lower vapor pressure than the pure solvent. |
What are color and hardness physical properties of? | elements | cells | ions | matter | A: You can see that snow and sand have a different color. You can also feel that snow is softer than sand. Both color and hardness are physical properties of matter. |
What are steroid hormones made of? | organisms | water | amino acid | lipids | Steroid hormones are made of lipids, such as phospholipids and cholesterol. They are fat soluble, so they can diffuse across the plasma membrane of target cells and bind with receptors in the cytoplasm of the cell (see Figure below ). The steroid hormone and receptor form a complex that moves into the nucleus and influences the expression of genes, essentially acting as a transcription factor. Examples of steroid hormones include cortisol and sex hormones. |
How many processes contribute to the emergence of viral diseases? | two | one | four | three | |
What type of scale is the richter scale? | asymmetric | dimensional | algorithmic | logarithmic | 7. Like the Richter scale, the moment magnitude scale is logarithmic. The 2011 Tōhoku earthquake in Japan was 9.0 and did tremendous damage. A few months earlier, an 8.8 struck Chile and did much less damage. Why?. |
Where is pedocal soil commonly found? | slopes | deserts | forests | grasslands | Pedocal is the soil common in grasslands. The more arid climate increases calcium in the soil. Pedocal is not as fertile. |
What are the key cells in the immune response? | leukocytes | keratinocytes | erythrocytes | lymphocytes | Lymphocytes are the key cells in the immune response. They are leukocytes that become activated by a particular antigen. There are two major type of lymphocytes: B cells and T cells. |
Where are most chloroplasts found in plants? | flowers | roots | stems | leaves | In plants, most chloroplasts are found in the leaves. Therefore, all the raw materials needed for photosynthesis must be present in the leaves. These materials include light, water, and carbon dioxide. The shape of the leaves gives them a lot of surface area to absorb light for photosynthesis. Roots take up water from the soil. Stems carry the water from the roots to the leaves. Carbon dioxide enters the leaves through tiny openings called stomata. (The oxygen released during photosynthesis also exits the leaves through the stomata. ). |
What type of x-linked trait is color blindness? | predominant | conscientiousness trait | dominant | recessive | Pedigree for Color Blindness. Color blindness is an X-linked recessive trait. Mothers pass the recessive allele for the trait to their sons, who pass it to their daughters. |
What do you call a condensation reaction in which an ester is formed from an alcohol and a carboxylic acid? | decarboxylation | transesterification | esterisation | esterification | An esterification is a condensation reaction in which an ester is formed from an alcohol and a carboxylic acid. Esterification is a subcategory of condensation reactions because a water molecule is produced in the reaction. The reaction is catalyzed by a strong acid, usually sulfuric acid. When the carboxylic acid butanoic acid is heated with an excess of methanol and a few drops of sulfuric acid, the ester methyl butanoate is produced. Methyl butanoate has the scent of pineapples. The reaction is shown below with both molecular and structural formulas. |
These types of cella support young, growing parts of a plant? | angular cells | pinworm cells | epidermal cells | collenchyma cells | |
What can be used to convert the energy provided by the sun to usable electrical energy? | Power Plants | Wind Mills | Pannels | solar cells | Solar cells convert the energy in sunlight to electrical energy. They contain a material such as silicon that absorbs light energy and gives off electrons. |
Most plant cells have a large central what? | membranes | nuclei | loci | vacuole | Most plant cells have a large central vacuole . It can make up as much as 90 percent of a plant cell’s total volume. The central vacuole is like a large storage container. It may store substances such as water, enzymes, and salts. It may have other roles as well. For example, the central vacuole helps stems and leaves hold their shape. It may also contain pigments that give flowers their colors. |
When you heat a pot of water on a stove top, energy moves from the pot to its metal handle by what process? | thermal radiation | induction | convection | conduction | Sunlight is turned into electricity at a solar power plant. These power plants use a large group of mirrors to focus sunlight on one place. This place is called a receiver ( Figure below ). At the receiver, a liquid such as oil or water is heated to a high temperature. The liquid transfers its heat by conduction . In conduction, energy moves between two objects that are in contact. The higher temperature object transfers heat to the lower temperature object. For example, when you heat a pot of water on a stove top, energy moves from the pot to its metal handle by conduction. At a solar power plant, the energy conducted by the heated liquid is used to make electricity. |
Of all the mineral nutrients, what contributes the most to plant growth and crop yields? | silicon | oxygen | methane | nitrogen | |
What do you call a reaction that consumes energy as it is carried out? | unstable | autotrophic | exothermic | endothermic | The exothermic reaction on the left releases energy. The endothermic reaction on the right consumes energy. |
What type of rain dissolves and damages stone buildings and statues? | stored rain | plastic rain | morning rain | acid rain | A: Acid rain dissolves and damages stone buildings and statues. The Figure below shows a statue that has been damaged by acid rain. |
What organ packages nutrients absorbed by the digestive system; produces plasma proteins, clotting factors, and bile; and disposes of worn-out cell components and waste products? | liver | heart | brain | liver | Hepatic Portal System The liver is a complex biochemical processing plant. It packages nutrients absorbed by the digestive system; produces plasma proteins, clotting factors, and bile; and disposes of worn-out cell components and waste products. Instead of entering the circulation directly, absorbed nutrients and certain wastes (for example, materials produced by the spleen) travel to the liver for processing. They do so via the hepatic portal system (Figure 20.43). Portal systems begin and end in capillaries. In this case, the initial capillaries from the stomach, small intestine, large intestine, and spleen lead to the hepatic portal vein and end in specialized capillaries within the liver, the hepatic sinusoids. You saw the only other portal system with the hypothalamic-hypophyseal portal vessel in the endocrine chapter. The hepatic portal system consists of the hepatic portal vein and the veins that drain into it. The hepatic portal vein itself is relatively short, beginning at the level of L2 with the confluence of the superior mesenteric and splenic veins. It also receives branches from the inferior mesenteric vein, plus the splenic veins and all their tributaries. The superior mesenteric vein receives blood from the small intestine, two-thirds of the large intestine, and the stomach. The inferior mesenteric vein drains the distal third of the large intestine, including the descending colon, the sigmoid colon, and the rectum. The splenic vein is formed from branches from the spleen, pancreas, and portions of the stomach, and the inferior mesenteric vein. After its formation, the hepatic portal vein also receives branches from the gastric veins of the stomach and cystic veins from the gall bladder. The hepatic portal vein delivers materials from these digestive and circulatory organs directly to the liver for processing. Because of the hepatic portal system, the liver receives its blood supply from two different sources: from normal systemic circulation via the hepatic artery and from the hepatic portal vein. The liver processes the blood from the portal system to remove certain wastes and excess nutrients, which are stored for later use. This processed blood, as well as the systemic blood that came from the hepatic artery, exits the liver via the right, left, and middle hepatic veins, and flows into the inferior vena cava. Overall systemic blood composition remains relatively stable, since the liver is able to metabolize the absorbed digestive components. |
What is defined as a push or pull acting on an object? | work | effort | motion | force | Force is defined as a push or pull acting on an object. Forces include gravity, friction, and applied force. |
How much time does the moon take to complete one revolution around the earth? | one week | one year | one day | one month |
Subsets and Splits
No saved queries yet
Save your SQL queries to embed, download, and access them later. Queries will appear here once saved.