question
stringlengths 17
246
| distractor3
stringlengths 1
36
| distractor1
stringlengths 1
32
| distractor2
stringlengths 1
27
| correct_answer
stringlengths 1
33
| support
stringlengths 0
2.94k
|
|---|---|---|---|---|---|
What term is used to describe the variety of life and its processes, including the variety of living organisms, the genetic differences among them, and the communities and ecosystems in which they occur? | evolution | biosphere | habitat | biodiversity | Biodiversity refers to the variety of life and its processes, including the variety of living organisms, the genetic differences among them, and the communities and ecosystems in which they occur. Scientists have identified about 1.9 million species alive today. They are divided into the six kingdoms of life shown in Figure below . Scientists are still discovering new species. Thus, they do not know for sure how many species really exist today. Most estimates range from 5 to 30 million species. |
What kind of a disorder is tay-sachs disease? | accumulated disease | vitamin difficiency | a type of cancer | inherited disorder | |
A rock that contains important minerals is called what, a term associated with mining? | gem | jewel | coal | ore | An ore is a rock that contains important minerals. |
Besides the size of their crystals, how are igneous rocks grouped? | by color | by shapes | impurities they contain | minerals they contain | Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. |
Convection is the heat transfer by the macroscopic movement of a what? | tissue | gravity | gases | fluid | 14.4 Heat Transfer Methods Equally as interesting as the effects of heat transfer on a system are the methods by which this occurs. Whenever there is a temperature difference, heat transfer occurs. Heat transfer may occur rapidly, such as through a cooking pan, or slowly, such as through the walls of a picnic ice chest. We can control rates of heat transfer by choosing materials (such as thick wool clothing for the winter), controlling air movement (such as the use of weather stripping around doors), or by choice of color (such as a white roof to reflect summer sunlight). So many processes involve heat transfer, so that it is hard to imagine a situation where no heat transfer occurs. Yet every process involving heat transfer takes place by only three methods: 1. Conduction is heat transfer through stationary matter by physical contact. (The matter is stationary on a macroscopic scale—we know there is thermal motion of the atoms and molecules at any temperature above absolute zero. ) Heat transferred between the electric burner of a stove and the bottom of a pan is transferred by conduction. Convection is the heat transfer by the macroscopic movement of a fluid. This type of transfer takes place in a forced-air furnace and in weather systems, for example. Heat transfer by radiation occurs when microwaves, infrared radiation, visible light, or another form of electromagnetic radiation is emitted or absorbed. An obvious example is the warming of the Earth by the Sun. A less obvious example is thermal radiation from the human body. |
Hypersection by an endocrine gland is often caused by what? | viruses | calcium | inflammation | tumor | Hypersecretion by an endocrine gland is often caused by a tumor. For example, a tumor of the pituitary gland can cause hypersecretion of growth hormone. If this occurs in childhood, it results in very long arms and legs and abnormally tall stature by adulthood. The condition is commonly known as gigantism (see Figure below ). See Giants - Part 1 - Pituitary Gigantism and Acromegaly at http://www. youtube. com/watch?v=Ebhf1qKVA9A for information about pituitary giants. |
What gland secretes growth hormones? | thyroid | pineal | adrenal | pituitary | Hormones That Influence Osteoblasts and/or Maintain the Matrix Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth in several ways. It triggers chondrocyte proliferation in epiphyseal plates, resulting in the increasing length of long bones. GH also increases calcium retention, which enhances mineralization, and stimulates osteoblastic activity, which improves bone density. GH is not alone in stimulating bone growth and maintaining osseous tissue. Thyroxine, a hormone secreted by the thyroid gland promotes osteoblastic activity and the synthesis of bone matrix. During puberty, the sex hormones (estrogen in girls, testosterone in boys) also come into play. They too promote osteoblastic activity and production of bone matrix, and in addition, are responsible for the growth spurt that often occurs during adolescence. They also promote the conversion of the epiphyseal plate to the epiphyseal line (i. , cartilage to its bony remnant), thus bringing an end to the longitudinal growth of bones. Additionally, calcitriol, the active form of vitamin D, is produced by the kidneys and stimulates the absorption of calcium and phosphate from the digestive tract. |
We must remember that the formal charge calculated for an atom is not the actual charge of the atom in the molecule. formal charge is only a useful bookkeeping procedure; it does not indicate the presence of these? | electron bonds | isotopes | negative charges | actual charges | Calculating Formal Charge The formal charge of an atom in a molecule is the hypothetical charge the atom would have if we could redistribute the electrons in the bonds evenly between the atoms. Another way of saying this is that formal charge results when we take the number of valence electrons of a neutral atom, subtract the nonbonding electrons, and then subtract the number of bonds connected to that atom in the Lewis structure. Thus, we calculate formal charge as follows: formal charge = # valence shell electrons (free atom) − # lone pair electrons − 1 # bonding electrons 2 We can double-check formal charge calculations by determining the sum of the formal charges for the whole structure. The sum of the formal charges of all atoms in a molecule must be zero; the sum of the formal charges in an ion should equal the charge of the ion. We must remember that the formal charge calculated for an atom is not the actual charge of the atom in the molecule. Formal charge is only a useful bookkeeping procedure; it does not indicate the presence of actual charges. |
What kind of rock layer makes up the bottom of an aquifer? | crystalline | invisible | porous | impermeable | A rock layer must be porous and permeable to be a good aquifer. An impermeable layer makes up the bottom of an aquifer. |
The amniotic egg is a shared ancestral character for which clade? | avian | trichina | xerophyte | amniota | What is the largest clade in this diagram? Shared Characteristics Organisms evolve from common ancestors and then diversify. Scientists use the phrase “descent with modification” because even though related organisms have many of the same characteristics and genetic codes, changes occur. This pattern repeats over and over as one goes through the phylogenetic tree of life: 1. A change in the genetic makeup of an organism leads to a new trait which becomes prevalent in the group. Many organisms descend from this point and have this trait. New variations continue to arise: some are adaptive and persist, leading to new traits. With new traits, a new branch point is determined (go back to step 1 and repeat). If a characteristic is found in the ancestor of a group, it is considered a shared ancestral character because all of the organisms in the taxon or clade have that trait. The vertebrate in Figure 20.10 is a shared ancestral character. Now consider the amniotic egg characteristic in the same figure. Only some of the organisms in Figure 20.10 have this trait, and to those that do, it is called a shared derived character because this trait derived at some point but does not include all of the ancestors in the tree. The tricky aspect to shared ancestral and shared derived characters is the fact that these terms are relative. The same trait can be considered one or the other depending on the particular diagram being used. Returning to Figure 20.10, note that the amniotic egg is a shared ancestral character for the Amniota clade, while having hair is a shared derived character for some organisms in this group. These terms help scientists distinguish between clades in the building of phylogenetic trees. |
Lyme disease is caused by what kind of organim? | algae | Virus | bacterium | bacteria | Humans have literally walked into some new bacterial diseases. When people come into contact with wild populations, they may become part of natural cycles of disease transmission. Consider Lyme disease. It’s caused by bacteria that normally infect small, wild mammals, such as mice. A tick bites a mouse and picks up the bacteria. The tick may then bite a human who invades the natural habitat. Through the bite, the bacteria are transmitted to the human host. |
What is the side to side movement of the mandible called? | shifting | twitching | cycling | excursion | Excursion Excursion is the side to side movement of the mandible. Lateral excursion moves the mandible away from the midline, toward either the right or left side. Medial excursion returns the mandible to its resting position at the midline. |
A moraine is sediment deposited by what? | wind | human-caused scarring | river erosion | glacier | A moraine is sediment deposited by a glacier. A ground moraine is a thick layer of sediments left behind by a retreating glacier. An end moraine is a low ridge of sediments deposited at the end of the glacier. It marks the greatest distance the glacier advanced. |
The development of the respiratory system in the fetus begins at about? | 4 days | 2 weeks | 4 months | 4 weeks | 22.7 Embryonic Development of the Respiratory System The development of the respiratory system in the fetus begins at about 4 weeks and continues into childhood. Ectodermal tissue in the anterior portion of the head region invaginates posteriorly, forming olfactory pits, which ultimately fuse with endodermal tissue of the early pharynx. At about this same time, an protrusion of endodermal tissue extends anteriorly from the foregut, producing a lung bud, which continues to elongate until it forms the laryngotracheal bud. The proximal portion of this structure will mature into the trachea, whereas the bulbous end will branch to form two bronchial buds. These buds then branch repeatedly, so that at about week 16, all major airway structures are present. Development progresses after week 16 as respiratory bronchioles and alveolar ducts form, and extensive vascularization occurs. Alveolar type I cells also begin to take shape. Type II pulmonary cells develop and begin to produce small amounts of surfactant. As the fetus grows, the respiratory system continues to expand as more alveoli develop and more surfactant is produced. Beginning at about week 36 and lasting into childhood, alveolar precursors mature to become fully functional alveoli. At birth, compression of the thoracic cavity forces much of the fluid in the lungs to be expelled. The first inhalation inflates the lungs. Fetal breathing movements begin around week 20 or 21, and occur when contractions of the respiratory muscles cause the fetus. |
What are plants that grow on other plants called? | bryophytes | fungi | parasites | epiphytes | Plants called epiphytes grow on other plants. They obtain moisture from the air instead of the soil. Most epiphytes are ferns or orchids that live in rainforests. Host trees provide support for the plants. They allow epiphytes to get air and sunlight high above the forest floor. This lets the plants get out of the shadows on the forest floor so they can get enough light for photosynthesis. Being elevated may also reduce the risk of being eaten by herbivores. In addition, it may increase the chances of pollination by wind. |
An object attached to a spring sliding on a frictionless surface is an uncomplicated type of what device? | atomic watch | wheel and axle | pendulum | simple harmonic oscillator | Figure 16.9 An object attached to a spring sliding on a frictionless surface is an uncomplicated simple harmonic oscillator. When displaced from equilibrium, the object performs simple harmonic motion that has an amplitude X and a period T . The object’s maximum speed occurs as it passes through equilibrium. The stiffer the spring is, the smaller the period. |
What controls all five senses? | endocrine system | circulatory system | skin cells | nervous system | |
Where in the target cells are intracellular receptor proteins found? | ribosomes or nucleus | mucus or nucleus | membrane or mitochondria | cytoplasm or nucleus | |
The components of a mixture keep their own identity when they combine, so they retain what type of properties, such as boiling point and ability to dissolve? | thermal | thermal | internal | physical | The components of a mixture keep their own identity when they combine, so they retain their physical properties. Examples of physical properties include boiling point, ability to dissolve, and particle size. When components of mixtures vary in physical properties such as these, processes such as boiling, dissolving, or filtering can be used to separate them. |
A thermite reaction is thermodynamically spontaneous, and because it is associated with a significant release of heat, it is regarded as what? | endothermic | biochemical | endotropic | exothermic | Thermodynamic spontaneity. The highly exothermic and dramatic thermite reaction is thermodynamically spontaneous. Reactants of aluminum and a metal oxide, usually iron, which are stable at room temperature, are ignited either in the presence of heat or by the reaction of potassium permanganate and glycerin. The resulting products are aluminum oxide, free and molten elemental metal, and a great deal of heat, which makes this an excellent method for on-site welding. Because this reaction has its own oxygen supply, it can be used for underwater welding as well. |
What do nectar-feeding bats do to flowers? | consume | defecate | illuminate | pollinate | Mammals also interact with other species in many symbiotic relationships. For example, bats have established mutually beneficial relationships with plants. Nectar-feeding bats receive a tasty treat from each flower, and, in return, they pollinate the flowers. That means they transfer pollen from one flower to another, allowing the plant to reproduce. Non-flying mammalian pollinators include marsupials, primates, and rodents. In most cases, these animals visit flowers to eat their nectar, and end up with pollen stuck to their bodies. When the animal visits another flower to eat the nectar, the pollen is transferred to that flower. |
Ecological succession refers to the change in the numbers and types of species that live in what groups? | biomes | movements | colonies | communities | Communities are not usually static. The numbers and types of species that live in them generally change over time. This is called ecological succession . Important cases of succession are primary and secondary succession. |
What broad group of organisms is characterized by sensory organs, the ability to move, internal digestion and sexual reproduction? | fungi | protists | plants | animals | Animals are multicellular eukaryotes that lack cell walls. All animals are heterotrophs. They have sensory organs, the ability to move, and internal digestion. They also have sexual reproduction. |
Foodborne illness, food allergies, or a food intolerance cause symptoms in what system? | skeletal | respiratory | circulatory | digestive | Most of the time, you probably aren’t aware of your digestive system. It works well without causing any problems. But most people have problems with their digestive system at least once in a while. Did you ever eat something that didn’t “agree” with you? Maybe you had a stomachache or felt sick to your stomach? Maybe you had diarrhea? These could be symptoms of foodborne illness, food allergies, or a food intolerance. |
The number of what subatomic particles determines an element’s atomic number and is used to distinguish one element from another? | electrons | neutrons | quarks | protons | Atomic Number and Mass Atoms of each element contain a characteristic number of protons and electrons. The number of protons determines an element’s atomic number and is used to distinguish one element from another. The number of neutrons is variable, resulting in isotopes, which are different forms of the same atom that vary only in the number of neutrons they possess. Together, the number of protons and the number of neutrons determine an element’s mass number, as illustrated in Figure 2.3. Note that the small contribution of mass from electrons is disregarded in calculating the mass number. This approximation of mass can be used to easily calculate how many neutrons an element has by simply subtracting the number of protons from the mass number. Since an element’s isotopes will have slightly different mass numbers, scientists also determine the atomic mass, which is the calculated mean of the mass number for its naturally occurring isotopes. Often, the resulting number contains a fraction. For example, the atomic mass of chlorine (Cl) is 35.45 because chlorine is composed of several isotopes, some (the majority) with atomic mass 35 (17 protons and 18 neutrons) and some with atomic mass 37 (17 protons and 20 neutrons). |
What regulates the time of flowering in many species? | pollenation | wind patterns | spirogyra | photoperiodism | |
What is the most common cause of down syndrome? | chromosome 21 | trisomy 22 | gametes 21 | trisomy 21 | |
What occurs not only as organisms grow, but as they reproduce. | flight division | proteins division | experimental division | cell division | Cell division occurs not only as organisms grow. It also occurs when they reproduce. |
What useful tool helps scientists work with, understand and make predictions about extremely complex systems? | speculation | guesses | assumptions | models | Scientific models are useful tools for scientists. Most of Earth's systems are extremely complex. Models allow scientists to work with systems that are nearly impossible to study as a whole. Models help scientists to understand these systems. They can analyze and make predictions about them using the models. There are different types of models. |
A dilute solution is one that has a relatively small amount of what? | pH level | density | saturated fat | dissolved solute | There are cultures that have no numbers above three. Anything greater than that is simply referred to as “much” or “many”. We recognize how limited this form of calculation is, but we do some of the same thing. There are several ways to express the amount of solute in a solution in a quantitative manner. The concentration of a solution is a measure of the amount of solute that has been dissolved in a given amount of solvent or solution. A concentrated solution is one that has a relatively large amount of dissolved solute. A dilute solution is one that has a relatively small amount of dissolved solute. However, those terms are vague and we need to be able to express concentration with numbers. |
Each bond includes a sharing of electrons between atoms. two electrons are shared in a single bond; four electrons are shared in a double bond; and six electrons are shared in this? | magnetic bond | ionic bond | quadruple bond | triple bond | Each bond includes a sharing of electrons between atoms. Two electrons are shared in a single bond; four electrons are shared in a double bond; and six electrons are shared in a triple bond. |
What is the process of breaking an individual into parts followed by regeneration called? | destruction | minimization | erosion | fragmentation | View this video (http://openstaxcollege. org/l/budding_hydra2) to see a hydra budding. Fragmentation Fragmentation is the breaking of an individual into parts followed by regeneration. If the animal is capable of fragmentation, and the parts are big enough, a separate individual will regrow from each part. Fragmentation may occur through accidental damage, damage from predators, or as a natural form of reproduction. Reproduction through. |
The left atrium receives oxygen-rich blood from which organs? | liver | pancreas | brain | lungs | The left atrium receives oxygen-rich blood from the lungs. |
If the water vapor condenses in liquid droplets as clouds form, what is released in the atmosphere? | electricity | oxygen | hydrogen | heat | Another important example of the combination of phase change and convection occurs when water evaporates from the oceans. Heat is removed from the ocean when water evaporates. If the water vapor condenses in liquid droplets as clouds form, heat is released in the atmosphere. Thus, there is an overall transfer of heat from the ocean to the atmosphere. This process is the driving power behind thunderheads, those great cumulus clouds that rise as much as 20.0 km into the stratosphere. Water vapor carried in by convection condenses, releasing tremendous amounts of energy. This energy causes the air to expand and rise, where it is colder. More condensation occurs in these colder regions, which in turn drives the cloud even higher. Such a mechanism is called positive feedback, since the process reinforces and accelerates itself. These systems sometimes produce violent storms, with lightning and hail, and constitute the mechanism driving hurricanes. |
An increase in the number of gas molecules in the same volume container causes what to increase? | power | friction | energy | pressure | An increase in the number of gas molecules in the same volume container increases pressure. |
What do induction cooktops have under their surface? | screws | Chambers | clumps | electromagnets | Induction cooktops have electromagnets under their surface. The magnetic field is varied rapidly producing eddy currents in the base of the pot, causing the pot and its contents to increase in temperature. Induction cooktops have high efficiencies and good response times but the base of the pot needs to be ferromagnetic, iron or steel for induction to work. |
How many types of molecular orbitals can form from the overlap of two atomic s orbitals on adjacent atoms? | ten | three | six | two | There are two types of molecular orbitals that can form from the overlap of two atomic s orbitals on adjacent atoms. The two types are illustrated in Figure 8.29. The in-phase combination produces a lower energy σs molecular orbital (read as "sigma-s") in which most of the electron density is directly between the nuclei. The out-of-phase addition (which can also be thought of as subtracting the wave functions) produces a higher energy molecular orbital (read as "sigma-s-star") molecular orbital in which there is a node between the nuclei. The asterisk signifies that the orbital is an antibonding orbital. Electrons in a σs orbital are attracted by both nuclei at the same time and are more stable (of lower energy) than they would be in the isolated atoms. Adding electrons to these orbitals creates a force that holds the two nuclei together, so we call these orbitals bonding orbitals. Electrons in the σ*s orbitals are located well away from the region between the two nuclei. The attractive force between the nuclei and these electrons pulls the two nuclei apart. Hence, these orbitals are called antibonding orbitals. Electrons fill the lower-energy bonding orbital before the higher-energy antibonding orbital, just as they fill lower-energy atomic orbitals before they fill higher-energy atomic orbitals. |
Salicylic acid is used in the synthesis of acetylsalicylic acid, or more commonly called? | Tylenol | smelling salts | antacid | aspirin | Salicylic acid is used in the synthesis of acetylsalicylic acid, or aspirin. One gram dissolves in 460 mL of water to create a saturated solution with a pH of 2.40. |
What is the term for groups of cells with a similar appearance and a common function, and describes how cells are organized? | kidney | muscle | heart | tissue | |
What kind of weather do psychrophiles need to grow and reproduce? | water temperatures | mixed temperatures | Hot temperatures | cold temperatures | Psychrophiles grow and reproduce in cold temperatures. The optimal growth temperature of some psychrophiles is 15°C or lower; they cannot grow in temperatures above 20°C. The environments that psychrophiles inhabit are found all over Earth. Psychrophiles live in such places as permafrost soils, deep-ocean waters, Arctic and Antarctic glaciers and snowfields. |
What creates new seafloor in the rift valleys? | continental drift | sedimentation | crust spreading | seafloor spreading | Volcanoes erupt at mid-ocean ridges, such as the Mid-Atlantic ridge. Seafloor spreading creates new seafloor in the rift valleys. This type of volcanism makes all of the ocean floor! Where a hotspot is located along the ridge, such as at Iceland, volcanoes grow high enough to create islands ( Figure below ). |
The building blocks of proteins are called what? | protein acids | boric acids | mutation acids | amino acids | 2.3 Biological Molecules Living things are carbon-based because carbon plays such a prominent role in the chemistry of living things. The four covalent bonding positions of the carbon atom can give rise to a wide diversity of compounds with many functions, accounting for the importance of carbon in living things. Carbohydrates are a group of macromolecules that are a vital energy source for the cell, provide structural support to many organisms, and can be found on the surface of the cell as receptors or for cell recognition. Carbohydrates are classified as monosaccharides, disaccharides, and polysaccharides, depending on the number of monomers in the molecule. Lipids are a class of macromolecules that are nonpolar and hydrophobic in nature. Major types include fats and oils, waxes, phospholipids, and steroids. Fats and oils are a stored form of energy and can include triglycerides. Fats and oils are usually made up of fatty acids and glycerol. Proteins are a class of macromolecules that can perform a diverse range of functions for the cell. They help in metabolism by providing structural support and by acting as enzymes, carriers or as hormones. The building blocks of proteins are amino acids. Proteins are organized at four levels: primary, secondary, tertiary, and quaternary. Protein shape and function are intricately linked; any change in shape caused by changes in temperature, pH, or chemical exposure may lead to protein denaturation and a loss of function. |
Type 1 diabetes and gigantism are examples of what type of disorder? | inborn errors of metabolism | cardiac diseases | respiratory diseases | endocrine diseases | Endocrine system diseases are fairly common. An endocrine disease usually involves the secretion of too much or not enough hormone by an endocrine hormone. Examples of endocrine diseases are gigantism and Type 1 diabetes. |
In photosynthesis, what process involving carbon dioxide and oxygen occurs through small, regulated openings called stomata? | transpiration | osmosis | fertilization | gas exchange | Although the equation looks simple, the many steps that take place during photosynthesis are actually quite complex. Before learning the details of how photoautotrophs turn sunlight into food, it is important to become familiar with the structures involved. In plants, photosynthesis generally takes place in leaves, which consist of several layers of cells. The process of photosynthesis occurs in a middle layer called the mesophyll. The gas exchange of carbon dioxide and oxygen occurs through small, regulated openings called stomata (singular: stoma), which also play roles in the regulation of gas exchange and water balance. The stomata are typically located on the underside of the leaf, which helps to minimize water loss. Each stoma is flanked by guard cells that regulate the opening and closing of the stomata by swelling or shrinking in response to osmotic changes. In all autotrophic eukaryotes, photosynthesis takes place inside an organelle called a chloroplast. For plants, chloroplastcontaining cells exist in the mesophyll. Chloroplasts have a double membrane envelope (composed of an outer membrane and an inner membrane). Within the chloroplast are stacked, disc-shaped structures called thylakoids. Embedded in the thylakoid membrane is chlorophyll, a pigment (molecule that absorbs light) responsible for the initial interaction between light and plant material, and numerous proteins that make up the electron transport chain. The thylakoid membrane encloses an internal space called the thylakoid lumen. As shown in Figure 8.6, a stack of thylakoids is called a granum, and the liquid-filled space surrounding the granum is called stroma or “bed” (not to be confused with stoma or “mouth,” an opening on the leaf epidermis). |
Which molecules are made of one carbon and four hydrogen atoms? | particles | fats | proteins | hydrocarbons | Hydrocarbons are molecules made of one carbon and four hydrogen atoms. |
Atoms of different elements have different numbers of what? | nucleus | electrons | neutrons | protons | All protons are identical. For example, hydrogen protons are exactly the same as protons of helium and all other elements, or pure substances. However, atoms of different elements have different numbers of protons. In fact, atoms of any given element have a unique number of protons that is different from the numbers of protons of all other elements. For example, a hydrogen atom has just one proton, whereas a helium atom has two protons. The number of protons in an atom determines the electrical charge of the nucleus. The nucleus also contains neutrons, but they are neutral in charge. The one proton in a hydrogen nucleus, for example, gives it a charge of +1, and the two protons in a helium nucleus give it a charge of +2. To learn more about the relationship between protons and elements, go to this URL:. |
The lancelet lacks what feature that distinguishes vertebrates? | mouth | feet | skin | backbone | |
What is a reptiles skin covered in to protect them from drying out? | dye | bacteria | oil | scales | The cell cycle is a repeating series of events that cells go through. It includes growth, DNA synthesis, and cell division. In eukaryotic cells, there are two growth phases, and cell division includes mitosis. |
In sexual reproduction, the fusion of haploid gametes forms a diploid cell called what? | gamete | gonad | fetus | zygote | |
Gabbro is a dark dense rock that can be found in what? | soil | surface crust | mantle | oceanic crust | Mark A. Wilson (Department of Geology, The College of Wooster). Gabbro is a dark dense rock that can be found in oceanic crust . Public Domain. |
What provides clear evidence of evolution? | mutations | biologists | extinction | fossils | Fossils are a window into the past. They provide clear evidence that evolution has occurred. Scientists who find and study fossils are called paleontologists . How do they use fossils to understand the past? Consider the example of the horse, shown in the Figure below . The fossil record shows how the horse evolved. |
About half of what type of radiation is absorbed in the first 15 meters of water? | natural | surface | polar | solar | |
What begins with a diploid cell and ends with four haploid cells? | urinalysis | electrolysis | mitosis | meiosis | Fertilization joins haploid gametes into a diploid zygote. How do gametes end up with half the amount, a haploid amount, of DNA? The mechanism that produces haploid cells is meiosis. Meiosis is a type of cell division that halves the number of chromosomes. Meiosis is specific to gamete producing cells in the gonads. Meiosis begins with a diploid cell and ends with four haploid cells. These cells eventually differentiate into mature sperm or egg cells. During meiosis the pairs of homologous chromosomes separate and segregate randomly to produce gametes with one chromosome from each pair. Only germ cells like spermatocytes and oocytes, can undergo meiosis. |
Two smaller isotopes, more neutrons, and heat energy are the products of what type of reaction? | fusion | Reaction | diffusion | fission | Nuclear fission reactions involve collision of a slow neuron with an element, usually uranium. The products of a fission reaction are two smaller isotopes, more neutrons, and heat energy. |
What percentage of the field is tilled in traditional plowing? | 75% | 50 % | 60 % | 100% | |
Traits controlled by genes on the sex chromosomes are called what? | chromosome-linked traits | male-related traits | gender-linked traits | sex-linked traits | Traits controlled by genes on the sex chromosomes are called sex-linked traits . One gene on the Y chromosome determines male sex. There are very few other genes on the Y chromosome, which is the smallest human chromosome. There are hundreds of genes on the much larger X chromosome. None is related to sex. Traits controlled by genes on the X chromosome are called X-linked traits. |
What structures are at the end of the long air passages in the lungs? | Larynx | Oral Cavity | chloride | alveoli | During respiration, oxygen gets pulled into the lungs and enters the blood by passing across the thin alveoli membranes and into the capillaries. The alveoli are at the end of the long air passages. |
What is a disease caused by the same virus that causes chicken pox? | hepatitis | gout | diabetes | shingles | Shingles. Shingles is a disease caused by the same virus that causes chicken pox. |
In a solution what is the substance a solute dissolves in is called? | atoms | particles | gas | solvent | A solution forms when one substance dissolves in another. The substance that dissolves is called the solute . The substance it dissolves in is called the solvent . For example, ocean water is a solution in which the solute is salt and the solvent is water. In this example, a solid (salt) is dissolved in a liquid (water). However, matter in any state can be the solute or solvent in a solution. Solutions may be gases, liquids, or solids. In Table below and the video at the URL below, you can learn about solutions involving other states of matter. |
What is it called when sound is reflected off an object? | reverberation | signal | amplification | echo | |
Acidic hydrogen atoms are those which will be transferred to what? | another atom | water | a cup | a base | Acids can further be categorized based on how many acidic hydrogen atoms they contain. Acidic hydrogen atoms are those which will be transferred to a base. A monoprotic acid has only one acidic hydrogen that would be transferred to a strong base, whereas a polyprotic acid has two or more. Common monoprotic acids include HCl, HBr, and HNO 3 . A common diprotic acid is sulfuric acid (H 2 SO 4 ), and phosphoric acid (H 3 PO 4 ) provides an example of a triprotic acid. In each case, all hydrogens are available to participate in acid-base reactions. However, that is not the case for all acidic molecules. For example, in acetic acid (CH 3 COOH), only the hydrogen bonded to the oxygen atom is acidic. The other three hydrogens are covalently bonded to carbon and cannot be removed by any of the bases that we will consider in this chapter. |
In an ecosystem, what do you call organisms like lions that capture and kill other animals for food? | leaders | hunters | alphas | predators | Consumers get their food in different ways Figure below . Grazers feed on living organisms without killing them. A rabbit nibbles on leaves and a mosquito sucks a drop of blood. Predators , like lions, capture and kill animals for food. The animals they eat are called prey . Even some plants are consumers. Pitcher plants trap insects in their sticky fluid in their “pitchers. ” The insects are their prey. Scavengers eat animals that are already dead. This hyena is eating the remains of a lion’s prey. Decomposers break down dead organisms and the wastes of living things. This dung beetle is rolling a ball of dung (animal waste) back to its nest. The beetle will use the dung to feed its young. The mushrooms pictured are growing on a dead log. They will slowly break it down. This releases its nutrients to the soil. |
What type of diseases occur when the immune system attacks normal body cells? | inflammatory | gastrointestinal | liver | autoimmune | Autoimmune diseases occur when the immune system attacks normal body cells. |
Most modern seed plants are angiosperms, which produce seeds in the ovaries of what basic structure? | leaves | stems | cells | flowers | Most modern seed plants are angiosperms that produce seeds in the ovaries of flowers. Ovaries may develop into fruits. Flowers attract pollinators, and fruits are eaten by animals, which help disperse the seeds. |
What is produced by the end of meiosis? | three haploid cells | sixteen haploid cells | eight haploid cells | four haploid cells | At the end of meiosis, four haploid cells have been produced, but the cells are not yet gametes. The cells need to develop before they become mature gametes capable of fertilization. The development of haploid cells into gametes is called gametogenesis . |
In the u. s. , the majority of electricity is produced by burning coal or what else? | wind power | hydroelectic | solar | fossil fuels | In the U. S. , the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution that harms the health of living things. The air pollution also causes acid rain and contributes to global warming. In addition, fossil fuels are nonrenewable resources, so if we keep using them, they will eventually run out. The main advantage of nuclear energy is that it doesn’t release air pollution or cause the other environmental problems associated with the burning of fossil fuels. On the other other hand, radioactive elements are nonrenewable like fossil fuels and could eventually be used up. |
Farming practices leave some soil exposed and vulnerable to what natural process? | sediment | migration | rust | erosion | Farming leaves some soil exposed to erosion. |
Matter is made up of a mixture of things called what? | structures | segments | compounds | elements | Matter is made up of a mixture of things called elements. Elements are substances that cannot be broken down into simpler substances. There are more than 100 known elements, and 92 occur naturally around us. The others have been made only in the laboratory. |
Water seeps into the ground through permeable material and stops when it reaches what? | Coral | Bed Rock | Lava | impermeable rock | Water seeps into the ground through permeable material and stops when it reaches an impermeable rock. Predict the purpose of the well in the diagram. |
Vertebrate animals have two major body cavities, the dorsal and what is the other? | functional cavity | anterior cavity | proximal cavity | spinal cavity | Figure 33.6 Vertebrate animals have two major body cavities. The dorsal cavity, indicated in green, contains the cranial and the spinal cavity. The ventral cavity, indicated in yellow, contains the thoracic cavity and the abdominopelvic cavity. The thoracic cavity is separated from the abdominopelvic cavity by the diaphragm. The thoracic cavity is separated into the abdominal cavity and the pelvic cavity by an imaginary line parallel to the pelvis bones. (credit: modification of work by NCI). |
There are 20 different common amino acids needed to make what organic compound? | cells | lipids | nutron | proteins | Proteins are organic compounds that contain carbon, hydrogen, oxygen, nitrogen, and, in some cases, sulfur. These compounds may many essential functions within the cell (see below). Proteins are made of smaller units called amino acids . There are 20 different common amino acids needed to make proteins. All amino acids have the same basic structure, which is shown in Figure below . Only the side chain (labeled R in the figure) differs from one amino acid to another. These side chains can vary in size from just one hydrogen atom in glycine to a large heterocyclic group in tryptophan. The variable side chain gives each amino acid unique properties. The side chains can also characterize the amino acid as (1) nonpolar or hydrophobic, (2) neutral (uncharged) but polar, (3) acidic, with a net negative charge, and (4) basic, with a net positive charge at neutral pH. |
Sponges exemplify what type of arrangement, where different cells are specialized for different functions, but each cell works alone? | organ-level organization | independent organization | commensalism | cell-level organization | Sponges have cell-level organization, in which different cells are specialized for different functions, but each cell works alone. For example, some cells digest food, while other cells let water pass through the sponge. |
What type of chemical reactions release energy? | biochemical reactions | sulfuric reactions | endothermic reactions | exothermic reactions | Some chemical reactions are exothermic, which means they release energy. Other chemical reactions are endothermic, which means they consume energy. |
Some types of minerals form balls called what? | fistulas | cancers | microbes | nodules | Some types of minerals form balls called nodules. Nodules may be tiny or as big as basketballs. They contain manganese, iron, copper, and other useful minerals. As many as 500 billion tons of nodules lie on the ocean floor! However, mining them would be very costly and could be harmful to the ocean environment. |
According to the special theory of relativity, no physical object can equal or exceed the speed of what? | weight | air | energy | light | A result of the special theory of relativity is that no physical object can equal or exceed the speed of light. From the equation for relativistic mass, it can be seen that as the object is accelerated faster and faster, its mass becomes greater and greater. The greater mass would require an even greater force to accelerate it. If the velocity of the mass ever reached the speed of light, the denominator of the equation would become zero and the mass would become infinite. The energy required to accelerate an infinite mass would also be infinite. The fact that light itself travels at the speed , implies that light has a zero rest mass. Of course, light is never at rest. |
What is another word for cellular drinking? | altostratus | hypothalamus | cellular hydration | pinocytosis | Pinocytosis , or cellular drinking, occurs when the plasma membrane folds inward to form a channel allowing dissolved substances to enter the cell, as shown in Figure below . When the channel is closed, the liquid is encircled within a pinocytic vesicle. |
What do you call water that flows out of the ground where an aquifer meets the surface? | stream | oasis | waterfall | spring | Water that flows out of the ground where an aquifer meets the surface is called a spring. Spring water may contain dissolved minerals. It may also be heated by magma in the crust. Heated groundwater that erupts from the ground under pressure is called a geyser. |
What do you call the basic units of the structure and function of living things? | proteins | molecules | enzymes | cells | If you look at living matter with a microscope—even a simple light microscope—you will see that it consists of cells. Cells are the basic units of the structure and function of living things. They are the smallest units that can carry out the processes of life. All organisms are made up of one or more cells, and all cells have many of the same structures and carry out the same basic life processes. Knowing the structures of cells and the processes they carry out is necessary to understanding life itself. |
What is the conversion of a solid to a gas called? | education | speciation | amplification | sublimation | (a) Sublimation is the conversion of a solid (relatively high density) to a gas (much lesser density). This process yields a much greater dispersal of matter, since the molecules will occupy a much greater volume after the solid-to-gas transition. (b) Condensation is the conversion of a gas (relatively low density) to a liquid (much greater density). This process yields a much lesser dispersal of matter, since the molecules will occupy a much lesser volume after the solid-to-gas transition. (c) The process in question is dilution. The food dye molecules initially occupy a much smaller volume (the drop of dye solution) than they occupy once the process is complete (in the full glass of water). The process therefore entails a greater dispersal of matter. The process may also yield a more uniform dispersal of matter, since the initial state of the system involves two regions of different dye concentrations (high in the drop, zero in the water), and the final state of the system contains a single dye concentration throughout. |
Which form of dialysis has a patient’s blood pass through a length of tubing that travels through an artificial kidney machine? | arterial dialysis | peritoneal dialysis | limbic dialysis | hemodialysis | In one form of dialysis, called hemodialysis, a patient’s blood is passed though a length of tubing that travels through an artificial kidney machine (also called adialysis machine). A section of tubing composed of a semipermeable membrane is immersed in a solution of sterile water, glucose, amino acids, and certain electrolytes. The osmotic pressure of the blood forces waste molecules and excess water through the membrane into the sterile solution. Red and white blood cells are too large to pass through the membrane, so they remain in the blood. After being cleansed in this way, the blood is returned to the body. Dialysis is a continuous process, as the osmosis of waste materials and excess water takes time. Typically, 5–10 lb of waste-containing fluid is removed in each dialysis session, which can last 2–8 hours and must be performed several times a week. Although some patients have been on dialysis for 30 or more years, dialysis is always a temporary solution because waste materials are constantly building up in the bloodstream. A more permanent solution is a kidney transplant. Cell walls are semipermeable membranes, so the osmotic pressures of the body’s fluids have important biological consequences. If solutions of different osmolarity exist on either side of the cells, solvent (water) may pass into or out of the cells, sometimes with disastrous results. Consider what happens if red blood cells are placed in a hypotonic solution, meaning a solution of lower osmolarity than the liquid inside the cells. The cells swell up as water enters them, disrupting cellular activity and eventually causing the cells to burst. This process is called hemolysis. If red blood cells are placed in ahypertonic solution, meaning one having a higher osmolarity than exists inside the cells, water leaves the cells to dilute the external solution, and the red blood cells shrivel and die. This process is called crenation. Only if red blood cells are placed inisotonic solutions that have the same osmolarity as exists inside the cells are they unaffected by negative effects of osmotic pressure. Glucose solutions of about 0.31 M, or sodium chloride solutions of about 0.16 M, are isotonic with blood plasma. |
What are the only type of elements capable of changing into different elements? | adjacent elements | noble gases | metalloids | radioactive elements | Some elements naturally change into different elements. To understand how this happens, first recall what an element is. An element is a unique substance, with a unique number of protons in the nucleus of its atoms. No two elements have the same number of protons. For example, carbon atoms always have six protons. If an atom has a different number of protons, it isn’t carbon. For an element to change into a different element, then, it must change the number of protons in the nucleus of its atoms. This happens only in radioactive elements. |
What does the inside of all cells also contain? | chromosomes | chloroplasm | protein | cytosol | The inside of all cells also contain a jelly-like substance called cytosol . Cytosol is composed of water and other molecules, including enzymes , which are proteins that speed up the cell’s chemical reactions. Everything in the cell sits in the cytosol, like fruit in a jello mold. The term cytoplasm refers to the cytosol and all of the organelles, the specialized compartments of the cell. The cytoplasm does not include the nucleus. As a prokaryotic cell does not have a nucleus, the DNA is in the cytoplasm. |
What anatomical structures insulate, protect and provide sensory input? | salivary glands | teeth | fingernails | hair | Hair helps to insulate and protect the body. Head hair is especially important in preventing heat loss from the body. Eyelashes and eyebrows protect the eyes from water, dirt, and other irritants. Hairs in the nose trap dust particles and microorganisms in the air and prevent them from reaching the lungs. Hair also provides sensory input when objects brush against it or it sways in moving air. |
Known for its beautiful rings, what is the second largest planet in the solar system? | Venus | Mars | jupiter | saturn | Saturn, shown in Figure below , is famous for its beautiful rings. Saturn is the second largest planet in the solar system. Saturn’s mass is about 95 times Earth's mass. The gas giant is 755 times Earth’s volume. Despite its large size, Saturn is the least dense planet in our solar system. Saturn is actually less dense than water. This means that if there were a bathtub big enough, Saturn would float! In Roman mythology, Saturn was the father of Jupiter. Saturn orbits the Sun once about every 30 Earth years. |
What kind of waves are used in radar guns? | radio waves | x-rays | WIFI | microwaves | Electromagnetic waves carry energy through matter or space as vibrating electric and magnetic fields. Electromagnetic waves have a wide range of wavelengths and frequencies. The complete range is called the electromagnetic spectrum. The Figure below shows all the waves of the spectrum. The waves used in radar guns are microwaves. |
On what lobe of the liver is the gallbladder near? | internal lobe | left lobe | central lobe | right lobe | The Gallbladder The gallbladder is 8–10 cm (~3–4 in) long and is nested in a shallow area on the posterior aspect of the right lobe of the liver. This muscular sac stores, concentrates, and, when stimulated, propels the bile into the duodenum via the common bile duct. It is divided into three regions. The fundus is the widest portion and tapers medially into the body, which in turn narrows to become the neck. The neck angles slightly superiorly as it approaches the hepatic duct. The cystic duct is 1–2 cm (less than 1 in) long and turns inferiorly as it bridges the neck and hepatic duct. The simple columnar epithelium of the gallbladder mucosa is organized in rugae, similar to those of the stomach. There is no submucosa in the gallbladder wall. The wall’s middle, muscular coat is made of smooth muscle fibers. When these fibers contract, the gallbladder’s contents are ejected through the cystic duct and into the bile duct (Figure 23.27). Visceral peritoneum reflected from the liver capsule holds the gallbladder against the liver and forms the outer coat of the gallbladder. The gallbladder's mucosa absorbs water and ions from bile, concentrating it by up to 10-fold. |
What process is used for cell growth, repair of cuts and replacement of worn out cells? | pollination | reproduction | binary fission | cell division | Yes, just like this car, cells cannot last forever. Cells do eventually wear out. At that point, they need to be replaced. This is one reason that your cells divide. New cells that result after cells divide are also used for growth and to repair cuts. |
What do astronomers term the stretching of space that causes the distance between galaxies to increase? | contracting universe | maintaining universe | draining universe | expanding universe | An inflating balloon is not exactly like the expanding Universe. The surface of a balloon has only two dimensions, while space has three dimensions. But it is true that space itself is stretching out between galaxies like the rubber stretches when a balloon is inflated. This stretching of space, which causes the distance between galaxies to increase, is what astronomers mean by the expansion of the Universe. |
What are the two types of digestive systems invertebrates may have? | gastric and monogastric | complete and simple | complete and fluid | complete and incomplete | Invertebrates have one of two types of digestive system. They are called incomplete and complete digestive systems. Both are shown in Figure below . An incomplete digestive system consists of a digestive cavity with one opening. The single opening serves as both mouth and anus. A complete digestive system consists of a digestive tract with two openings. One opening is the mouth. The other is the anus. |
What does the gradient of bicoid protein determine? | vertical-horizontal plane | shallow - posterior axis | east-west axis | anterior-posterior axis | |
What term is used to describe a cancer that has spread? | ostracized | destabilized | galvanized | metastasized | Isotopes can be very useful in scans to locate cancer cells. This patient has multiple tumors that have spread (metastasized) from the main tumor. A radioisotope has been attached to antibodies that bind to specific cancer cells. The very dark spots in the armpits, neck, and groin represent areas where tumor cells exist. |
What is the most abundant of all vertebrate classes, and the most recent to evolve? | mammals | bony fishes | reptiles | birds | Of all vertebrate classes, birds are the most numerous, even though they evolved most recently. Why have birds been so successful? The answer is flight. Being able to fly opened up a whole new world to birds: the world of the air above the land and water. |
How many calories of energy does one gram of protein provide? | 5 | 2 | 1 | 4 | If you eat more protein than you need for these functions, the extra protein is used for energy. One gram of protein provides 4 Calories of energy, the same as carbohydrates. A 13-year-old needs to eat about 34 grams of protein a day. Figure below shows good food sources of protein. |
What is the cure of cancer known as? | regeneration | metabolism | rejuvenation | remission | If leukemia is treated early, it usually can be cured. In fact, many cancers can be cured, which is known as remission, if treated early. Treatment of cancer often involves removing a tumor with surgery. This may be followed by other types of treatments. These treatments may include drugs (known as chemotherapy) and radiation therapy, which kill cancer cells. |
What is the outer layer of the exoskeleton called? | epithelium | bristle | epidermis | cuticle | Segmented bodies with an exoskeleton . The outer layer of the exoskeleton is called the cuticle . It is made up of two layers. The outer layer, or exocuticle , is thin, waxy, and water-resistant. The inner layer is much thicker. The exocuticle is extremely thin in many soft-bodied insects, such as caterpillars. |
In what stage of their life cycle do insects begin developing their wings? | pupal | crystalline | larva | pupa | During pupa stage, wing development begins, after which the adult emerges. |
The speed of sound depends on what? | temperature | light | volume | medium | The speed of sound depends on the medium. Medium (20°C) Speed of Sound Waves (m/s). |
Why is the life cycle of plants so complex? | asexual reproduction | metamorphosis | pollination process | alternation of generation | The life cycle of all plants is complex because it is characterized by alternation of generations. Plants alternate between diploid sporophyte and haploid gametophyte generations, and between sexual and asexual reproduction. The ability to reproduce both sexually and asexually gives plants the flexibility to adapt to changing environments. Their complex life cycle allows for great variation. |
While elements are represented by chemical symbols, chemical formulas represent what? | solutions | extracts | pollutants | compounds | Elements are represented by chemical symbols. Examples are H for hydrogen and O for oxygen. Compounds are represented by chemical formulas . You’ve already seen the chemical formula for water. It’s H 2 O. The subscript 2 after the H shows that there are two atoms of hydrogen in a molecule of water. The O for oxygen has no subscript. When there is just one atom of an element in a molecule, no subscript is used. Table below shows some other examples of compounds and their chemical formulas. |
What is a form of cell division in prokaryotic organisms that produces identical offspring? | mitosis | nuclear fission | germination | binary fission | Binary fission is a form of cell division in prokaryotic organisms that produces identical offspring. |