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[context]: Summary Changes of state are examples of phase changes, or phase transitions. All phase changes are accompanied by changes in the energy of a system. Changes from a more-ordered state to a less-ordered state (such as a liquid to a gas) areendothermic. Changes from a less-ordered state to a more-ordered state... |
[context]: Meteoroids are smaller than asteroids, ranging from the size of boulders to the size of sand grains. When meteoroids enter Earth’s atmosphere, they vaporize, creating a trail of glowing gas called a meteor. If any of the meteoroid reaches Earth, the remaining object is called a meteorite.
[question]: When ... |
[context]: One type of radioactivity is alpha emission. What is an alpha particle? What happens to an alpha particle after it is emitted from an unstable nucleus?.
[question]: Alpha emission is a type of what?
[answer]: radioactivity |
[context]: The stored food in a seed is called endosperm . It nourishes the embryo until it can start making food on its own.
[question]: What is the stored food in a seed called?
[answer]: endosperm |
[context]: Occurrence, Preparation, and Compounds of Boron and Silicon Boron constitutes less than 0.001% by weight of the earth’s crust. In nature, it only occurs in compounds with oxygen. Boron is widely distributed in volcanic regions as boric acid, B(OH)3, and in dry lake regions, including the desert areas of Cali... |
[context]: 42.1 Circulatory systems link exchange surfaces with cells throughout the body.
[question]: What organ systems link exchange surfaces with cells throughout the body?
[answer]: circulatory |
[context]: An allergy occurs when the immune system attacks a harmless substance that enters the body from the outside. A substance that causes an allergy is called an allergen. It is the immune system, not the allergen, that causes the symptoms of an allergy.
[question]: What occurs when the immune system attacks a ... |
[context]: Enzymes are critical to the body’s healthy functioning. They assist, for example, with the breakdown of food and its conversion to energy. In fact, most of the chemical reactions in the body are facilitated by enzymes.
[question]: Most of the chemical reactions in the body are facilitated by what?
[answer... |
[context]: Usually, testing a hypothesis requires making observations or performing experiments. In this case, we will look into existing scientific literature to see if either of these hypotheses can be disproved, or if one or both can be supported by the data.
[question]: Testing what usually requires making observ... |
[context]: Water molecules move about continuously due to their kinetic energy. When a crystal of sodium chloride is placed into water, the water’s molecules collide with the crystal lattice. Recall that the crystal lattice is composed of alternating positive and negative ions. Water is attracted to the sodium chloride... |
[context]: One idea is that evolution happens. Evolution is a change in the inherited traits of organisms over time. Living things have changed as descendants diverged from common ancestors in the past.
[question]: What is defined as a change in the inherited traits of organisms over time?
[answer]: evolution |
[context]: What causes puberty to begin? The hypothalamus in the brain “tells” the pituitary gland to secrete hormones that target the testes. The main pituitary hormone involved is luteinizing hormone (LH) . It stimulates the testes to secrete testosterone. Testosterone, in turn, promotes protein synthesis and growth.... |
[context]: Seed plants called angiosperms produce seeds in the ovaries of flowers.
[question]: Where do angiosperms produce seeds in flowers?
[answer]: ovaries |
[context]: Some Eukarya are also single-celled, but many are multicellular. Some have a cell wall; others do not. However, the cells of all Eukarya have a nucleus and other organelles.
[question]: The cells of all eukarya have a what?
[answer]: nucleus |
[context]: Divergent plate boundaries produce huge mountain ranges under water in every ocean basin.
[question]: What type of plate boundaries produce huge mountain ranges in the ocean basin?
[answer]: divergent |
[context]: temperatures with electropositive metals such as those of groups 1 and 2 and aluminum produces ionic carbides, which contain discrete metal cations and carbon anions. The identity of the anions depends on the size of the second element. For example, smaller elements such as beryllium and aluminum give methid... |
[context]: Agents of Decomposition The fungus-like protist saprobes are specialized to absorb nutrients from nonliving organic matter, such as dead organisms or their wastes. For instance, many types of oomycetes grow on dead animals or algae. Saprobic protists have the essential function of returning inorganic nutrien... |
[context]: Ribosomes are small organelles and are the sites of protein synthesis (or assembly). They are made of ribosomal protein and ribosomal RNA, and are found in both eukaryotic and prokaryotic cells. Unlike other organelles, ribosomes are not surrounded by a membrane. Each ribosome has two parts, a large and a sm... |
[context]: Meiosis I begins after DNA replicates during interphase of the cell cycle. In both meiosis I and meiosis II , cells go through the same four phases as mitosis - prophase, metaphase, anaphase and telophase. However, there are important differences between meiosis I and mitosis. The eight stages of meiosis are... |
[context]: Earthquakes are primarily the result of plate tectonic motions. What type of stress would cause earthquakes at each of the three types of plate boundaries?.
[question]: What phenomenon is primarily the result of plate tectonic motions?
[answer]: earthquake |
[context]: Ganglia A ganglion is a group of neuron cell bodies in the periphery. Ganglia can be categorized, for the most part, as either sensory ganglia or autonomic ganglia, referring to their primary functions. The most common type of sensory ganglion is a dorsal (posterior) root ganglion. These ganglia are the cell... |
[context]: Under what conditions then, do gases behave least ideally? When a gas is put under high pressure, its molecules are forced closer together as the empty space between the particles is diminished. A decrease in the empty space means that the assumption that the volume of the particles themselves is negligible ... |
[context]: Each type of rock weathers in its own way. Certain types of rock are very resistant to weathering. Igneous rocks tend to weather slowly because they are hard. Water cannot easily penetrate them. Granite is a very stable igneous rock. Other types of rock are easily weathered because they dissolve easily in we... |
[context]: Enzymes are involved in most of the biochemical reactions that take place in organisms. About 4,000 such reactions are known to be catalyzed by enzymes, but the number may be even higher. Enzymes allow reactions to occur at the rate necessary for life.
[question]: What substances serve as catalysts in most... |
[context]: automobile axle drives a wheel, which has a much larger diameter than the axle. The MA is less than 1. (c) An ordinary pulley is used to lift a heavy load. The pulley changes the direction of the force T exerted by the cord without changing its magnitude. Hence, this machine has an MA of 1.
[question]: A p... |
[context]: Figure 14.3 The Tongue The tongue is covered with small bumps, called papillae, which contain taste buds that are sensitive to chemicals in ingested food or drink. Different types of papillae are found in different regions of the tongue. The taste buds contain specialized gustatory receptor cells that respon... |
[context]: What if you were to drop a bowling ball and a soccer ball at the same time from the same distance above the ground? The bowling ball has greater mass than the basketball, so the pull of gravity on it is greater. Would it fall to the ground faster? No, the bowling ball and basketball would reach the ground at... |
[context]: A pile of leaves slowly rots in the backyard. In the presence of oxygen, hydrogen can interact to make water. Gold can be stretched into very thin wires.
[question]: In the presence of oxygen, hydrogen can interact to make what?
[answer]: water |
[context]: The angle at which light bends when it enters a different medium depends on its change in speed. The greater the change in speed, the greater the angle of refraction is. For example, light refracts more when it passes from air to diamond than it does when it passes from air to water. That’s because the speed... |
[context]: FM radio is inherently less subject to noise from stray radio sources than AM radio. The reason is that amplitudes of waves add. So an AM receiver would interpret noise added onto the amplitude of its carrier wave as part of the information. An FM receiver can be made to reject amplitudes other than that of ... |
[context]: Figure 8.11 The sun emits energy in the form of electromagnetic radiation. This radiation exists at different wavelengths, each of which has its own characteristic energy. All electromagnetic radiation, including visible light, is characterized by its wavelength.
[question]: What form of radiation is the e... |
[context]: The core is the Sun's innermost layer. The core is plasma. It has a temperature of around 15 million degrees Celsius (C). Nuclear fusion reactions create the immense temperature. In these reactions, hydrogen atoms fuse to form helium. This releases vast amounts of energy. The energy moves towards the outer l... |
[context]: To grow and develop, you must form new cells. Imagine how often your cells must divide during a growth spurt. Growing just an inch requires countless cell divisions. Your body must produce new bone cells, new skin cells, new cells in your blood vessels and so on.
[question]: A growth spurt requires constan... |
[context]: All animals have innate behaviors, even human beings. Can you think of human behaviors that do not have to be learned? Chances are, you will have a hard time thinking of any. The only truly innate behaviors in humans are called reflex behaviors . They occur mainly in babies. Like innate behaviors in other an... |
[context]: The pressure of the earth’s atmosphere, as with any fluid, increases with the height of the column of air. In the case of earth’s atmosphere, there are some complications. The density of the air is not uniform but decreases with altitude. Additionally there is no distinct top surface from which height can be... |
[context]: Internal Respiration Internal respiration is gas exchange that occurs at the level of body tissues (Figure 22.23). Similar to external respiration, internal respiration also occurs as simple diffusion due to a partial pressure gradient. However, the partial pressure gradients are opposite of those present at... |
[context]: Below the topsoil is the “B” horizon. This is also called the subsoil . Soluble minerals and clays accumulate in the subsoil. Because it has less organic material, this layer is lighter brown in color than topsoil. It also holds more water due to the presence of iron and clay. There is less organic material ... |
[context]: Conceptual Questions 19.1 Electric Potential Energy: Potential Difference 1. Voltage is the common word for potential difference. Which term is more descriptive, voltage or potential difference? 2. If the voltage between two points is zero, can a test charge be moved between them with zero net work being don... |
[context]: The crocodilian digestive system is highly adapted to their lifestyle. Crocodilians are known to swallow stones, known as gastroliths , which help digest their prey. The crocodilian stomach is divided into two chambers. The first is powerful and muscular. The other stomach is the most acidic digestive system... |
[context]: Populations usually grow bigger when they have what they need. How fast they grow depends on birth and death rates. They grow more slowly as they get close to the carrying capacity. This is the biggest population the environment can support.
[question]: When populations get close to the carrying capacity, ... |
[context]: Although air can transfer heat rapidly by convection, it is a poor conductor and thus a good insulator. The amount of available space for airflow determines whether air acts as an insulator or conductor. The space between the inside and outside walls of a house, for example, is about 9 cm (3.5 in) —large eno... |
[context]: Observations can happen on many scales. You can use a microscope to observe tiny things. You can use a telescope to observe distant things in space. To learn about the effects of climate change, you could observe Earth's surface. How would you make observations of Earth's surface? You could do this from the ... |
[context]: Carboxylic acids are weak acids (see the chapter on acids and bases), meaning they are not 100% ionized in water. Generally only about 1% of the molecules of a carboxylic acid dissolved in water are ionized at any given time. The remaining molecules are undissociated in solution. We prepare carboxylic acids ... |
[context]: Diseases of the endocrine system are relatively common. An endocrine disease usually involves the secretion of too much or not enough hormone. When too much hormone is secreted, it is called hypersecretion. When not enough hormone is secreted, it is called hyposecretion.
[question]: An endocrine disease us... |
[context]: For thousands of years, humans have understood that characteristics such as eye color, hair color, or even flower color are passed from one generation to the next. The passing of characteristics from parent to offspring is called heredity . Humans have long been interested in understanding heredity. Many her... |
[context]: 24.7 Nutrition and Diet Nutrition and diet affect your metabolism. More energy is required to break down fats and proteins than carbohydrates; however, all excess calories that are ingested will be stored as fat in the body. On average, a person requires 1500 to 2000 calories for normal daily activity, altho... |
[context]: Alkenes are unsaturated hydrocarbons with at least one double bond between carbon atoms.
[question]: What are unsaturated hydrocarbons with at least one double bond between carbon atoms called?
[answer]: alkenes |
[context]: All of the changes of state that occur between solid, liquid and gas are summarized in the diagram in the figure below. Freezing is the opposite of melting and both represent the equilibrium between the solid and liquid states. Evaporation occurs when a liquid turns to a gas. Condensation is the opposite of ... |
[context]: Sexual reproduction involves haploid gametes and produces a diploid zygote through fertilization.
[question]: Sexual reproduction involves haploid gametes and produces a diploid zygote through what process?
[answer]: fertilization |
[context]: Transform faults are the site of massive earthquakes.
[question]: Transform faults are the site of massive what?
[answer]: earthquakes |
[context]: The amount of reactants and products do not have to be equal. However, after equilibrium is attained, the amounts of reactants and products will be constant.
[question]: In a chemical reaction, the amounts of reactants and products will be constant when what state is attained?
[answer]: equilibrium |
[context]: Sepals protect the developing flower while it is still a bud. Sepals are usually green, which camouflages the bud from possible consumers.
[question]: What protects a developing flower while it is still a bud?
[answer]: sepals |
[context]: Gravity has traditionally been defined as a force of attraction between things that have mass. According to this conception of gravity, anything that has mass, no matter how small, exerts gravity on other matter. Gravity can act between objects that are not even touching. In fact, gravity can act over very l... |
[context]: Kidney failure may be treated with dialysis.
[question]: Dialysis is a treatment for failure of what organs?
[answer]: kidneys |
[context]: Children as young as 2 years of age can be vaccinated against viral meningitis.
[question]: What preventive measure can protect even young children against diseases such as viral meningitis?
[answer]: vaccination |
[context]: Renal plasma flow equals the blood flow per minute times the hematocrit. If a person has a hematocrit of 45, then the renal plasma flow is 55 percent. 1050*0.55 = 578 mL plasma/min.
[question]: Renal plasma flow equals the blood flow per minute times the what?
[answer]: hematocrit |
[context]: Lattice energy of an ionic solid is a measure of the strength of bonds in that ionic compound.
[question]: What does lattice energy of an ionic solid measure the strength of?
[answer]: bonds |
[context]: The concentration of an acid or base can be determined by titration.
[question]: Titration is a method to determine what in acids or bases?
[answer]: concentration |
[context]: Ulcers are sores in the lining of the stomach or duodenum that are usually caused by bacterial infections. They may also be caused by the acidic environment of the stomach. Stomach acids may damage the lining of the stomach. Symptoms typically include abdominal pain and bleeding. You can see how stomach ulce... |
[context]: As a cell prepares to divide, its DNA first forms one or more structures called chromosomes. A chromosome consists of DNA and protein molecules coiled into a definite shape. Chromosomes are circular in prokaryotes and rodlike in eukaryotes. You can see an example of a human chromosome in Figure below . The r... |
[context]: Arteries Serving the Upper Limbs As the subclavian artery exits the thorax into the axillary region, it is renamed the axillary artery. Although it does branch and supply blood to the region near the head of the humerus (via the humeral circumflex arteries), the majority of the vessel continues into the uppe... |
[context]: Immovable joints allow no movement because the bones at these joints are held securely together by dense collagen. The bones of the skull are connected by immovable joints.
[question]: The bones of the skull are connected by what type of joints?
[answer]: immovable |
[context]: The troposphere is the lowest layer of the atmosphere. All of the air you breathe is in the troposphere. All of Earth's weather—wind, rain, snow, heat—is in the troposphere. The troposphere is the lowest and most important layer of the atmosphere!.
[question]: What is the lowest layer of the atmosphere?
[... |
[context]: The key to continued growth and repair of plant cells is meristem . Meristem is a type of plant tissue consisting of undifferentiated cells that can continue to divide and differentiate. Meristem at the tips of roots and stems allows them to grow in length. This is called primary growth. Meristem within and ... |
[context]: The Phosphorus Cycle Phosphorus is an essential nutrient for living processes; it is a major component of nucleic acids and phospholipids, and, as calcium phosphate, makes up the supportive components of our bones. Phosphorus is often the limiting nutrient (necessary for growth) in aquatic, particularly fres... |
[context]: Genetics is the study of inheritance. Inheritance is the passing of traits from parents to offspring. How are these traits "passed"? Through DNA, which is the genetic material of all organisms. This concept will focus on genetics, inheritance, and DNA.
[question]: The passing of traits from parents to offs... |
[context]: If you’re like Tanya in this picture, you prefer your iced tea sweetened with sugar. Sweetened iced tea is a solution in which solid sugar (the solute) is dissolved in cold liquid tea, which is mostly water (the solvent). When you add sugar to tea, particles of water pull apart particles of sugar. The partic... |
[context]: Red litmus paper turns blue when placed in a basic solution.
[question]: Red litmus paper turns what color when placed in a basic solution?
[answer]: blue |
[context]: can occur in electrolytic cells by introducing a power supply, which supplies the energy to force the electrons to flow in the nonspontaneous direction. Electrolysis is done in solutions, which contain enough ions so current can flow. If the solution contains only one material, like the electrolysis of molte... |
[context]: Small nonpolar molecules can easily diffuse across the cell membrane. However, due to the hydrophobic nature of the lipids that make up cell membranes, polar molecules (such as water) and ions cannot do so. Instead, they diffuse across the membrane through transport proteins. A transport protein completely s... |
[context]: Vertebrates reproduce sexually, and almost all have separate male and female sexes. Aquatic species generally have external fertilization, whereas terrestrial species usually have internal fertilization. Vertebrates have one of three reproductive strategies, known as ovipary, ovovivipary, or vivipary.
[que... |
[context]: A cell membrane is essentially a mixture of phospholipids that form a phospholipid bilayer. One definition of a cell is a collection of molecules surrounded by a phospholipid bilayer that is capable of reproducing itself. The simplest cells are bacteria, which consist of only a single compartment surrounded ... |
[context]: Role of Feedback Loops The contribution of feedback loops to homeostasis will only be briefly reviewed here. Positive feedback loops are characterized by the release of additional hormone in response to an original hormone release. The release of oxytocin during childbirth is a positive feedback loop. The in... |
[context]: Pneumonia is a disease in which some of the alveoli of the lungs fill with fluid so they can no longer exchange gas. Symptoms of pneumonia typically include coughing, chest pain, difficulty breathing, and fatigue. Pneumonia may be caused by an infection or an injury to the lungs.
[question]: What the name ... |
[context]: Types of organisms that make glucose by photosynthesis are pictured in Figure below . They include plants, plant-like protists such as algae, and some kinds of bacteria. Living things that make glucose are called autotrophs ("self feeders"). All other living things obtain glucose by eating autotrophs (or org... |
[context]: Introduction Virtually every task performed by living organisms requires energy. Energy is needed to perform heavy labor and exercise, but humans also use energy while thinking, and even during sleep. In fact, the living cells of every organism constantly use energy. Nutrients and other molecules are importe... |
[context]: Compounds like sodium chloride form structures called crystals. A crystal is a rigid framework of many ions locked together in a repeating pattern. Ions are electrically charged forms of atoms. You can see a crystal of sodium chloride in the Figure below . It is made up of many sodium and chloride ions.
[q... |
[context]: Lipids are made of long chains consisting almost solely of carbon and hydrogen. These long chains are called fatty acids. Fatty acids may be saturated or unsaturated. Figure below shows an example of each type of fatty acid.
[question]: What are made of long chains consisting almost solely of carbon and hy... |
[context]: 0 .033 g 1 .117 g × 100 = 3 .0% When a series of measurements is precise but not accurate, the error is usually systematic. Systematic errors can be caused by faulty instrumentation or faulty technique. The difference between accuracy and precision is demonstrated in Skill Builder ES7.
[question]: When a s... |
[context]: Alloys that are mostly composed of mercury are known as amalgams . Amalgams often have special properties that stem from the fact that mercury exists as a liquid at room temperature. As a result, metal amalgams are used for a variety of purposes, including dentistry and the extraction of other pure metals su... |
[context]: Mirrors are made from highly reflective metal that is applied to a curved or flat piece of glass. Converging mirrors can be used to focus light – headlights, telescopes, satellite TV receivers, and solar cookers all rely on this principle.
[question]: What are made from highly reflective metal that is appl... |
[context]: Surface waves travel along the ground outward from an earthquake’s epicenter. Surface waves are the slowest of all seismic waves. They travel at 2.5 km (1.5 miles) per second. There are two types of surface waves. Love waves move side-to-side, much like a snake. Rayleigh waves produce a rolling motion as the... |
[context]: Intrapleural pressure is the pressure of the air within the pleural cavity, between the visceral and parietal pleurae. Similar to intra-alveolar pressure, intrapleural pressure also changes during the different phases of breathing. However, due to certain characteristics of the lungs, the intrapleural pressu... |
[context]: Protection. The skeleton supports and protects the soft organs of the body. For example, the skull surrounds the brain to protect it from injury. The bones of the rib cage help protect the heart and lungs.
[question]: What supports and protects the soft organs of the body?
[answer]: skeleton |
[context]: The Sun is Earth’s main source of energy. The Sun gives us both light and heat. The Sun changes hydrogen into helium through nuclear fusion. This releases huge amounts of energy. The energy travels to Earth mostly as visible light. The energy is carried through the empty space by radiation . We can use sunli... |
[context]: Strawberry plants have horizontal stems called stolons that run over the ground surface. If they take root, they form new plants.
[question]: What do you call the horizontal stems of a strawberry plant that run over the ground surface?
[answer]: stolons |
[context]: Glaciers are incredibly powerful agents of erosion.
[question]: Glaciers are incredibly powerful agents of what?
[answer]: erosion |
[context]: Asexual reproduction involves just one parent. It produces offspring that are genetically identical to the parent. Methods of asexual reproduction include binary fission, fragmentation, and budding.
[question]: What type of reproduction only involves one parent?
[answer]: asexual |
[context]: How metalloids behave in chemical interactions with other elements depends mainly on the number of electrons in the outer energy level of their atoms. Metalloids have from three to six electrons in their outer energy level. Boron, pictured in the Figure below , is the only metalloid with just three electrons... |
[context]: Annelids are divided into many repeating segments. The earthworm in Figure below is an annelid. You can clearly see its many segments. Segmentation of annelids is highly adaptive. Each segment has its own nerve and muscle tissues. This allows the animal to move very efficiently. Some segments can also be spe... |
[context]: The spermatids are transported from the testes to the epididymis. Involuntary muscular contraction moves the spermatids along.
[question]: The spermatids are transported from the testes to where?
[answer]: epididymis |
[context]: Grain boundaries. As a polycrystalline material solidifies, grains with irregular shapes form. The interfaces between grains constitute grain boundaries. (Squares represent unit cells within grains.
[question]: As a polycrystalline material solidifies, grains with irregular shapes form. the interfaces betw... |
[context]: Chromoplasts make and store pigments that give petals and fruit their orange and yellow colors.
[question]: What makes and stores pigments that give petals and fruit their orange and yellow colors?
[answer]: chromoplasts |
[context]: When electrons return to a lower energy level, they emit energy in the form of light.
[question]: When electrons return to a lower energy level, they emit the excess energy in the form of what?
[answer]: light |
[context]: Nearsightedness, or myopia, is the condition in which nearby objects are seen clearly, but distant objects are blurry. It occurs when the eyeball is longer than normal. This causes images to be focused in front of the retina. Myopia can be corrected with concave lenses. The lenses focus images farther back i... |
[context]: A liquid is a state of matter in which particles can slip past one another and take the shape of their container. However, the particles cannot pull apart and spread out to take the volume of their container.
[question]: In which state of matter do particles take the shape of their container, but cannot ex... |
[context]: Runoff is likely to cause more erosion if the land is bare. Plants help hold the soil in place. The runoff water in Figure below is brown because it eroded soil from a bare, sloping field. Can you find evidence of erosion by runoff where you live? What should you look for?.
[question]: Runoff is likely to ... |
[context]: Cations have positive charges, and anions have negative charges.
[question]: Cations have what type of charge?
[answer]: positive |
[context]: Colon The cecum blends seamlessly with the colon. Upon entering the colon, the food residue first travels up the ascending colon on the right side of the abdomen. At the inferior surface of the liver, the colon bends to form the right colic flexure (hepatic flexure) and becomes the transverse colon. The regi... |
[context]: Recall that our DNA is wound into chromosomes . Each of our chromosomes contains a long chain of DNA that encodes hundreds, if not thousands, of genes. Each of these genes can have slightly different versions from individual to individual. These variants of genes are called alleles . Each parent only donates... |
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