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What is a benefit of low sulfur coal over high sulfur coal?

less erosion

greater enerty

lower cost

less pollution

Low sulfur coal produces less pollution when burned than high sulfur coal. Name one factor that affects the sulfur content in coal.

Wings of bats and birds serve the same function. which body part should you study to understand ancestral differences?

skin inside wings

skull size

skin and feathers

bones inside wings

Wings of bats and birds serve the same function. Look closely at the bones inside the wings. The differences show they developed from different ancestors.

The best thermal conductors are also the best conductors of what, which is also related to the density of free electrons in them?

sound

light

pollution

electricity

Note that in Table 14.3, the best thermal conductors—silver, copper, gold, and aluminum—are also the best electrical conductors, again related to the density of free electrons in them. Cooking utensils are typically made from good conductors.

What tissue do clubmosses have that mosses do not?

chorophyll

dioxide tissue

nuclei

vascular tissue

Clubmosses can resemble mosses; however, clubmosses have vascular tissue, while mosses do not.

The average human body contains 5,830 g of what?

water

muscle

bacteria

blood

The average human body contains 5,830 g of blood. What mass of arsenic is present in the body if the amount in blood is 0.55 ppm?.

What type of speciation occurs when groups from the same species are geographically isolated for long periods?

prokaryotic

asexual

symbiotic

allopatric

Allopatric speciation occurs when groups from the same species are geographically isolated for long periods. Imagine all the ways that plants or animals could be isolated from each other:.

What can damage the hair cells lining the cochlea of the inner ear?

wavering sounds

amelodic sounds

unexpected sounds

loud sounds

Loud sounds can damage the hair cells lining the cochlea of the inner ear. Explain how this might affect the ability to hear sound.

The boiling point of a solution is higher than the boiling point of the pure solvent, but the opposite occurs with this?

liquidity point

dissolving point

evaporation point

freezing point

The boiling point of a solution is higher than the boiling point of the pure solvent, but the opposite occurs with the freezing point. The freezing point of a solution is lower than the freezing point of the pure solvent. Think of this by assuming that solute particles interfere with solvent particles coming together to make a solid, so it takes a lower temperature to get the solvent particles to solidify. This is called freezing point depression. The equation to calculate the change in the freezing point for a solution is similar to the equation for the boiling point elevation:.

What is the network of vessels and tissues that carry a clear fluid called lymph called?

cleansing system

excretory system

vessel system

lymphatic system

The lymphatic system is a network of vessels and tissues that carry a clear fluid called lymph. The lymphatic system ( Figure below ) spreads all around the body and filters and cleans the lymph of any debris, abnormal cells, or pathogens. Lymph vessels are tube-shaped, just like blood vessels, with about 500-600 lymph nodes (in an adult) attached. The lymphatic system works with the cardiovascular system to return body fluids to the blood. The lymphatic system and the cardiovascular system are often called the body’s two "circulatory systems. ".

What is defined as the change of water from its liquid phase to its gaseous phase?

transpiration

absorption

condensation

evaporation

Radiation, chemicals, and infectious agents are types of what?

dioxins

mutations

endogenous

mutagens

Types of mutagens include radiation, chemicals, and infectious agents.

What type of matter transmits light without scattering it?

bioluminescent

translucent

clean

transparent

Transparent matter is matter that transmits light without scattering it. Examples of transparent matter include air, pure water, and clear glass. You can see clearly through a transparent object, such as the revolving glass doors in the figure, because all the light passes straight through it.

Steam actually consists of tiny droplets of liquid what?

mercury

lead

methane

water

Steam actually consists of tiny droplets of liquid water. What you can’t see in the picture is the water vapor that is also present in the air above the spring. Water vapor is water in the gaseous state. It constantly rises up from the surface of boiling hot water. Why? At high temperatures, particles of a liquid gain enough energy to completely overcome the force of attraction between them, so they change to a gas. The gas forms bubbles that rise to the surface of the liquid because gas is less dense than liquid. The bubbling up of the liquid is called boiling. When the bubbles reach the surface, the gas escapes into the air. The entire process in which a liquid boils and changes to a gas that escapes into the air is called vaporization . You can watch an animation of the process at this URL: http://www. visionlearning. com/img/app/library/objects/Flash/VLObject-321-030317040343. swf.

What mammalian class has the greatest ability to learn?

rats

apes

reptiles

humans

In many ways, humans are unique among mammals. For example, we have bigger brains and a greater ability to learn than any other species in the mammalian class. In many ways, however, we are typical of the mammalian order to which we belong. That order is the Primate Order. To fully understand what it means to be human, you need to know more about this fascinating order of mammals.

What is the part of the cardiovascular system that carries oxygen-rich blood away from the heart, to the body, and returns oxygen-poor blood back to the heart?

molecular circulation

peripheral nervous system

somatic system

systemic circulation

Systemic circulation is the part of the cardiovascular system that carries oxygen-rich blood away from the heart, to the body, and returns oxygen-poor blood back to the heart. Oxygen-rich blood leaves the left ventricle through the aorta. Then it travels to the body's organs and tissues. The tissues and organs absorb the oxygen through the capillaries. Oxygen-poor blood is collected from the tissues and organs by tiny veins, which then flow into bigger veins, and, eventually, into the inferior vena cava and superior vena cava. This completes systemic circulation. The blood releases carbon dioxide and gets more oxygen in pulmonary circulation before returning to systemic circulation. The inferior vena cava returns blood from the body. The superior vena cava returns blood from the head.

What causes polarization in a neutral object?

signaling of charges

meaning of charges

combining of charges

separation of charges

Charging by Induction It is not necessary to transfer excess charge directly to an object in order to charge it. Figure 18.13 shows a method of induction wherein a charge is created in a nearby object, without direct contact. Here we see two neutral metal spheres in contact with one another but insulated from the rest of the world. A positively charged rod is brought near one of them, attracting negative charge to that side, leaving the other sphere positively charged. This is an example of induced polarization of neutral objects. Polarization is the separation of charges in an object that remains neutral. If the spheres are now separated (before the rod is pulled away), each sphere will have a net charge. Note that the object closest to the charged rod receives an opposite charge when charged by induction. Note also that no charge is removed from the charged rod, so that this process can be repeated without depleting the supply of excess charge. Another method of charging by induction is shown in Figure 18.14. The neutral metal sphere is polarized when a charged rod is brought near it. The sphere is then grounded, meaning that a conducting wire is run from the sphere to the ground. Since the earth is large and most ground is a good conductor, it can supply or accept excess charge easily. In this case, electrons are attracted to the sphere through a wire called the ground wire, because it supplies a conducting path to the ground. The ground connection is broken before the charged rod is removed, leaving the sphere with an excess charge opposite to that of the rod. Again, an opposite charge is achieved when charging by induction and the charged rod loses none of its excess charge.

Cells in blood include red blood cells, white blood cells, and what?

plasmids

protons

droplets

platelets

Cells in blood include red blood cells, white blood cells, and platelets.

What substance is created when a copper turns from reddish brown to greenish brown?

iron oxide

rust

copper alloy

copper oxide

A: Another example of matter changing color is a penny changing from reddish brown to greenish brown as it becomes tarnished. The color change indicates that a new chemical substance has been produced. Copper on the surface of the penny has combined with oxygen in the air to produce a different substance called copper oxide.

The egg shell membrane encloses the nucleus containing the genetic material and what?

exoskeleton

cerebellum

enamel

cytoplasm

The ostrich egg - unfertilized, of course. Yes, this egg, just like a human ovum, is just one cell. It is a gamete with a haploid number of chromosomes, formed through meiosis. The egg shell membrane encloses the nucleus containing the genetic material and the cytoplasm.

According to dalton's law, unless they chemically react with each other, individual gases in a mixture of gases do not affect each other’s what?

density

mass

weight

pressure

The Pressure of a Mixture of Gases: Dalton’s Law Unless they chemically react with each other, the individual gases in a mixture of gases do not affect each other’s pressure. Each individual gas in a mixture exerts the same pressure that it would exert if it present alone in the container (Figure 9.20). The pressure exerted by each individual gas in a mixture is called its partial pressure. This observation is summarized by Dalton’s law of partial pressures: The total pressure of a mixture of ideal gases is equal to the sum of the partial pressures of the component gases: P Total = P A + P B + P C + . = Σ i P i In the equation PTotal is the total pressure of a mixture of gases, PA is the partial pressure of gas A; PB is the partial pressure of gas B; PC is the partial pressure of gas C; and so on.

How many mass distinctions have radically altered the history of life?

four

six

one

five

The vector sum of all the torques acting on an object is called what?

homeostasis

peak capacity

torque load

net torque

the net torque is the vector sum of all the torques acting on the object. When adding torques it is necessary to subtract CW from CCW torques.

What determines how strongly an atom attracts electrons to itself?

gravity

enthalpy

ionization

electronegativity

The electronegativity of an atom determines how strongly it attracts electrons to itself.

Looking directly at what celestial object can cause blindness?

Haley's Comet

Moon

earth

sun

The Sun has many incredible surface features. Don't try to look at them, though! Looking directly at the Sun can cause blindness. Find the appropriate filters for a pair of binoculars or a telescope and enjoy!.

The amount of kinetic energy in a moving object depends directly on what two factors?

gravity and weight

revolution and velocity

inertia and momentum

mass and velocity

The amount of kinetic energy in a moving object depends directly on its mass and velocity. It can be calculated with the equation: .

What is the movement of fluid out of the capillaries called?

osmosis

diffusion

absorption

filtration

20.3 Capillary Exchange Small molecules can cross into and out of capillaries via simple or facilitated diffusion. Some large molecules can cross in vesicles or through clefts, fenestrations, or gaps between cells in capillary walls. However, the bulk flow of capillary and tissue fluid occurs via filtration and reabsorption. Filtration, the movement of fluid out of the capillaries, is driven by the CHP. Reabsorption, the influx of tissue fluid into the capillaries, is driven by the BCOP. Filtration predominates in the arterial end of the capillary; in the middle section, the opposing pressures are virtually identical so there is no net exchange,.

The prevalence of cervical cancer in the united states is very low because of regular screening exams called what?

Stavros smears

prostates exams

mammograms

pap smears

The prevalence of cervical cancer in the United States is very low because of regular screening exams called pap smears. Pap smears sample cells of the cervix, allowing the detection of abnormal cells. If pre-cancerous cells are detected, there are several highly effective techniques that are currently in use to remove them before they pose a danger. However, women in developing countries often do not have access to regular pap smears. As a result, these women account for as many as 80 percent of the cases of cervical cancer worldwide. In 2006, the first vaccine against the high-risk types of HPV was approved. There are now two HPV vaccines available: Gardasil® and Cervarix®. Whereas these vaccines were initially only targeted for women, because HPV is sexually transmitted, both men and women require vaccination for this approach to achieve its maximum efficacy. A recent study suggests that the HPV vaccine has cut the rates of HPV infection by the four targeted strains at least in half. Unfortunately, the high cost of manufacturing the vaccine is currently limiting access to many women worldwide.

There is a predictable amount of solute that can be dissolved at what?

room temperature

flat rate

light speed

specific temperature

There is a predictable amount of solute that can be dissolved at a specific temperature.

Carrier proteins bind and carry the molecules across what cell structure?

plastid

nucleus

cell wall

cell membrane

Carrier proteins bind and carry the molecules across the cell membrane. These proteins bind a molecule on one side of the membrane, change shape as they carry the molecule across the membrane, and deposit the molecule on the other side of the membrane. Even though a protein is involved in both these methods of transport, neither method requires energy. Therefore these are still types of passive transport.

As per hutton's unconformity, what happened to the intermediate layers of rock?

they expanded

they metamorphized

they fused

they eroded away

Look at the rock layers pictured below ( Figure below ); they show a feature called Hutton’s unconformity. The unconformity was discovered by James Hutton in the 1700s. Hutton saw that the lower rock layers are very old. The upper layers are much younger. There are no layers in between the ancient and recent layers. Hutton thought that the intermediate rock layers eroded away before the more recent rock layers were deposited.

What kind of summers do humid continental climates have?

wet summers

dry summers

warm summers

cold summers

Humid continental climates have warm winters and cold summers. Subarctic climates have cool short summers and very cold winters.

Compared to others, what type of liquid has a relatively high surface tension and heat capacity?

blood

oil

wine

water

Compared to other liquids, water has a relatively high surface tension and heat capacity. Both of these properties are partially a result of the strong hydrogen bonds that hold water molecules together.

Cilia and flagella are extensions of what?

cell wall

cell nucleus

protoplasm

plasma membrane

Cilia and flagella are extensions of the plasma membrane.

Mercury and lead, which was once widely used in paint and gasoline, are examples of what type of metals?

sulfuric heavy metals

gaseous heavy metals

alloys

toxic heavy metals

Toxic heavy metals include mercury and lead. Mercury is used in some industrial processes. It is also found in fluorescent light bulbs. Lead was once widely used in gasoline, paint, and pipes. It is still found in some products.

During karyogamy, the haploid nuclei contributed by the two parents fuse, which produces what?

cancer cells

mutated cells

arisen cells

diploid cells

What is polyisoprene better known as?

silicon

rayon

styrofoam

rubber

Polyisoprene is a polymer of isoprene and is better known as rubber. It is produced naturally by rubber trees, but several variants have been developed which demonstrate improvements on the properties of natural rubber.

Every chemical reaction occurs with a concurrent change in what?

hydrogen

neutrons

mass

energy

Every chemical reaction occurs with a concurrent change in energy.

What receives blood in the heart?

the epidermis

chamber

ventricle

the atria

The atria receive blood and the ventricles pump blood out of the heart.

Fatty acids, triglycerides, phospholipids, and steroids are examples of what?

proteins

tissues

enzymes

lipids

Lipids are a diverse class of relatively nonpolar biomolecules that generally do not dissolve well in water. Common types of lipids include fatty acids, triglycerides, phospholipids, and steroids.

Where in the cell does photosynthesis occur?

pathogen

cell wall

genome

chloroplast

Photosynthesis occurs in the chloroplast of the plant cell.

Sympathetic stimulation also triggers the release of epinephrine and norepinephrine, which enhance both cardiac output and what else?

digestion

vasodilation

inhibition

vasoconstriction

pressure and maintaining blood flow. Ultimately, however, blood volume will need to be restored, either through physiological processes or through medical intervention. In response to blood loss, stimuli from the baroreceptors trigger the cardiovascular centers to stimulate sympathetic responses to increase cardiac output and vasoconstriction. This typically prompts the heart rate to increase to about 180–200 contractions per minute, restoring cardiac output to normal levels. Vasoconstriction of the arterioles increases vascular resistance, whereas constriction of the veins increases venous return to the heart. Both of these steps will help increase blood pressure. Sympathetic stimulation also triggers the release of epinephrine and norepinephrine, which enhance both cardiac output and vasoconstriction. If blood loss were less than 20 percent of total blood volume, these responses together would usually return blood pressure to normal and redirect the remaining blood to the tissues. Additional endocrine involvement is necessary, however, to restore the lost blood volume. The angiotensin-reninaldosterone mechanism stimulates the thirst center in the hypothalamus, which increases fluid consumption to help restore the lost blood. More importantly, it increases renal reabsorption of sodium and water, reducing water loss in urine output. The kidneys also increase the production of EPO, stimulating the formation of erythrocytes that not only deliver oxygen to the tissues but also increase overall blood volume. Figure 20.21 summarizes the responses to loss of blood volume.

Not surprisingly, centipedes, millipedes and other members of the subphylum myriapoda are adapted to living on what?

tree

water

sand

land

Centipedes and millipedes belong to the subphylum Myriapoda, which contains 13,000 species. They all live on land, which makes sense as all those legs are more adapted to a terrestrial lifestyle, as opposed to an aquatic lifestyle.

What are found in moist forests that break down decaying plant material?

organism

trichina

spirogyra

myriapoda

Myriapoda are usually found in moist forests, where they break down decaying plant material.

By breaking down wastes and remains of dead organisms, decomposers perform what function in an ecosystem?

collecting

reproduction

symbiosis

recycling

Most prokaryotes get both energy and carbon from other living things. Many of them are decomposers. They break down wastes and remains of dead organisms. In this way, they help to recycle carbon and nitrogen through ecosystems.

What are sugars broken down into in your digestive system?

nicotine

starch

insulin

glucose

Sugars are small, simple carbohydrates. They are found in foods such as milk and fruit. Sugars in foods such as these are broken down by your digestive system to glucose, the simplest of all sugars. Glucose is taken up by cells for energy.

Approximately how many weeks does the fetal period last?

27 weeks

10 weeks

25 weeks

30 weeks

From the eighth week following fertilization until birth, the developing human being is called a fetus. Birth typically occurs at about 38 weeks after fertilization, so the fetal period generally lasts about 30 weeks. During this time, the organs complete their development. The fetus also grows rapidly in length and weight. Some of the specific changes that occur during the fetal stage are listed in Figure below .

Because dizygotic twins develop from two eggs fertilized by two sperm, they are no more identical than siblings born at what?

other eras

other times of day

different places

different times

birth of dizygotic (or fraternal) twins. Because dizygotic twins develop from two eggs fertilized by two sperm, they are no more identical than siblings born at different times. Much less commonly, a zygote can divide into two separate offspring during early development. This results in the birth of monozygotic (or identical) twins. Although the zygote can split as early as the two-cell stage, splitting occurs most commonly during the early blastocyst stage, with roughly 70–100 cells present. These two scenarios are distinct from each other, in that the twin embryos that separated at the two-cell stage will have individual placentas, whereas twin embryos that form from separation at the blastocyst stage will share a placenta and a chorionic cavity.

What is the plasma membrane mainly composed of?

carbon

filaments

antibodies

phospholipids

The plasma membrane is composed mainly of phospholipids, which consist of fatty acids and alcohol. The phospholipids in the plasma membrane are arranged in two layers, called a phospholipid bilayer . As shown in Figure below , each phospholipid molecule has a head and two tails. The head “loves” water (hydrophilic) and the tails “hate” water (hydrophobic). The water-hating tails are on the interior of the membrane, whereas the water-loving heads point outwards, toward either the cytoplasm or the fluid that surrounds the cell.

Astronomers have wondered if the universe is expanding fast enough to escape the pull of what?

light

kinetic energy

Coreolis effect

gravity

We know that the Universe is expanding. Astronomers have wondered if it is expanding fast enough to escape the pull of gravity. Would the Universe just expand forever? If it could not escape the pull of gravity, would it someday start to contract? This means it would eventually get squeezed together in a big crunch. This is the opposite of the Big Bang.

When someone falls, the kinetic energy the person has upon reaching the floor is the amount of what energy lost by falling through height?

nuclear energy

gravitational energy

thermal energy

potential energy

with a minus sign because the displacement while stopping and the force from floor are in opposite directions (cos θ = cos 180º = − 1) . The floor removes energy from the system, so it does negative work. The kinetic energy the person has upon reaching the floor is the amount of potential energy lost by falling through height.

What are protons and neutrons that make up the nucleus of an atom called?

electron shells

baryons

pions

nucleons

and Z, the atomic number, is the number of protons. The protons and neutrons that make up the nucleus of an atom are callednucleons, and an atom with a particular number of protons and neutrons is called anuclide. Nuclides with the same number of protons but different numbers of neutrons are called isotopes. Isotopes can also be represented by an alternative notation that uses the name of the element followed by the mass number, such as carbon-12. The stable isotopes of oxygen, for example, can be represented in any of the following ways:.

The sun, stars, moon, planets and comets are all type of what objects?

spacial

extraterrestrial

universal

celestrial

What is the total number of codons?

68

45

51

64

The mRNA is divided into three-base segments called codons. A codon is the segment of nucleotides that codes for an amino acid, or for a start or stop signal. There are 64 codons.

Solution nodes and antinodes are both areas of wave interference, but they differ in the presence of what condition?

speed

radiation

gravity

motion

Check Your Understanding Define nodes and antinodes. Solution Nodes are areas of wave interference where there is no motion. Antinodes are areas of wave interference where the motion is at its maximum point.

While similar to insects, what eight-legged invertebrates lack antennae or wings?

crustaceans

spiders

reptiles

arachnids

Arachnids do not have antennae or wings.

How many chromosomes do mature gametes contain?

17

19

13

23

Spermatogenesis As just noted, spermatogenesis occurs in the seminiferous tubules that form the bulk of each testis (see Figure 27.4). The process begins at puberty, after which time sperm are produced constantly throughout a man’s life. One production cycle, from spermatogonia through formed sperm, takes approximately 64 days. A new cycle starts approximately every 16 days, although this timing is not synchronous across the seminiferous tubules. Sperm counts—the total number of sperm a man produces—slowly decline after age 35, and some studies suggest that smoking can lower sperm counts irrespective of age. The process of spermatogenesis begins with mitosis of the diploid spermatogonia (Figure 27.5). Because these cells are diploid (2n), they each have a complete copy of the father’s genetic material, or 46 chromosomes. However, mature gametes are haploid (1n), containing 23 chromosomes—meaning that daughter cells of spermatogonia must undergo a second cellular division through the process of meiosis.

What is the term for land that has permanently frozen soil?

Arctic

ice desert

snow-field

permafrost

Permafrost is land with permanently frozen soil.

When sparks from a steel grinder react with oxygen, what do they form?

steel oxide

rust

spontaneous combustion

iron oxide

The sparks from a steel grinder are molten iron. The iron reacts with oxygen to form iron(III) oxide.

What should you learn that allows you to recognize and avoid the dangers of specific hazards when experimenting, such as flames or broken glass?

first aid safety symbols

available safety symbols

medical safety symbols

lab safety symbols

Lab safety symbols warn of specific hazards, such as flames or broken glass. Knowing the symbols allows you to recognize and avoid the dangers.

Motor vehicles account for almost half of the consumption of what?

electricity

hydrocarbon

greenhouse gases

fossil fuel

Motor vehicles account for almost half of fossil fuel use. Most vehicles run on gasoline, which comes from petroleum.

Bacterial stis can be cured with what?

antiviral drugs

pesticides

antioxidants

antibiotics

Most STIs are caused by bacteria or viruses. Bacterial STIs can be cured with antibiotics. Viral STIs cannot be cured. Once you are infected with a viral STI, you are likely to be infected for life.

Fats are also called triacylglycerols or triglycerides because of their what?

elemental type

atomic number

chemical weight

chemical structure

During this ester bond formation, three water molecules are released. The three fatty acids in the triacylglycerol may be similar or dissimilar. Fats are also called triacylglycerols or triglycerides because of their chemical structure. Some fatty acids have common names that specify their origin. For example, palmitic acid, a saturated fatty acid, is derived from the palm tree. Arachidic acid is derived from Arachis hypogea, the scientific name for groundnuts or peanuts. Fatty acids may be saturated or unsaturated. In a fatty acid chain, if there are only single bonds between neighboring carbons in the hydrocarbon chain, the fatty acid is said to be saturated. Saturated fatty acids are saturated with hydrogen; in other words, the number of hydrogen atoms attached to the carbon skeleton is maximized. Stearic acid is an example of a saturated fatty acid (Figure 3.14).

What mammalian structure allows the exchange of gases, nutrients, and other substances between the fetus and mother?

notochord

uterus

mitochondria

placenta

Placenta of a Placental Mammal (Human). The placenta allows the exchange of gases, nutrients, and other substances between the fetus and mother.

Fossil fuel consumption is a major contributor to global emissions of what gas?

methane

oxygen

carbon monoxide

carbon dioxide

Global carbon dioxide emissions from fossil fuel consumption and cement production. The black line represents all emission types combined. The colored lines show emissions from individual fossil fuels.

What is the main function of blood?

excretion of waste

digestion

respiration

to transport

The main function of blood is transport. Blood in arteries carries oxygen and nutrients to all the body’s cells. Blood in veins carries carbon dioxide and other wastes away from cells to be excreted. Blood also transports the chemical messengers called hormones to cells throughout the body where they are needed to regulate body functions. Blood has several other functions as well. For example, blood:.

Biotechnology is the use of biological agents for technological advancement. what two areas are the primary applications of this technology used?

medicine and philosophy

medicine and architecture

medicine and psychology

medicine and agriculture

Biotechnology is the use of biological agents for technological advancement. Biotechnology was used for breeding livestock and crops long before the scientific basis of these techniques was understood. Since the discovery of the structure of DNA in 1953, the field of biotechnology has grown rapidly through both academic research and private companies. The primary applications of this technology are in medicine (production of vaccines and antibiotics) and agriculture (genetic modification of crops, such as to increase yields). Biotechnology also has many industrial applications, such as fermentation, the treatment of oil spills, and the production of biofuels (Figure 17.2).

Unlike free-living species of flatworms that are predators or scavengers, what forms feed from the tissues of their hosts?

herbiverous

aquatic

mutualistic

parasitic

Flatworms The relationships among flatworms, or phylum Platyhelminthes, is being revised and the description here will follow the traditional groupings. Most flatworms are parasitic, including important parasites of humans. Flatworms have three embryonic germ layers that give rise to surfaces covering tissues, internal tissues, and the lining of the digestive system. The epidermal tissue is a single layer of cells or a layer of fused cells covering a layer of circular muscle above a layer of longitudinal muscle. The mesodermal tissues include support cells and secretory cells that secrete mucus and other materials to the surface. The flatworms are acoelomate, so their bodies contain no cavities or spaces between the outer surface and the inner digestive tract. Physiological Processes of Flatworms Free-living species of flatworms are predators or scavengers, whereas parasitic forms feed from the tissues of their hosts. Most flatworms have an incomplete digestive system with an opening, the “mouth,” that is also used to expel digestive.

When heat flows into an object, its thermal energy increases and so does its what?

color

matter

speed

temperature

When heat flows into an object, its thermal energy increases and so does its temperature.

What are telescopes that use lenses to bend light called?

layering telescopes

reflecting telescopes

sliding telescopes

refracting telescopes

Telescopes that use lenses to bend light are called refracting telescopes , or refractors ( Figure below ). The earliest telescopes were all refractors. Many amateur astronomers still use refractors today. Refractors are good for viewing details within our solar system. Craters on the surface of Earth’s Moon or the rings around Saturn are two such details.

The science of analyzing tree rings is called what?

estradiol

algorithms

conservation

dendrochronology

Which type of arthritis causes the immune system to attack joints?

Spondylarthropathies

Osteoarthritis

Gout

rheumatoid

In rheumatoid arthritis, the immune system attacks joints. This causes joint damage and pain.

A species is a subdivision of a genus in what classification system?

crocodilian system

calcareous system

mammalian

linnaean system

Linnaean Classification System: Classification of the Human Species. This chart shows the taxa of the Linnaean classification system. Each taxon is a subdivision of the taxon below it in the chart. For example, a species is a subdivision of a genus. The classification of humans is given in the chart as an example.

What is the force that pulls particles at the exposed surface of a liquid toward other liquid particles called?

transfer tension

conservative tension

shinking tension

surface tension

Two unique properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like the water droplet that has formed on the leaky faucet pictured in the Figure below . You can learn more about surface tension at this URL: http://io9. com/5668221/an-experiment-with-soap-water-pepper-and-surface-tension .

What state is achieved when the body's internal environment is kept more-or-less constant?

consciousness

cancerous

hypothesis

homeostasis

The organ systems of the body work together to carry out life processes and maintain homeostasis. The body is in homeostasis when its internal environment is kept more-or-less constant. For example, levels of sugar, carbon dioxide, and water in the blood must be kept within narrow ranges. This requires continuous adjustments. For example:.

Kinetic and potential are two forms of what?

exercise

pressure

fuel

energy

Energy is the ability to do work. When work is done, energy is transferred from one object to another. Energy can exist in different forms, such as electrical and chemical energy. Most forms of energy can also be classified as kinetic or potential energy.

Humans are unique in their ability to alter their environment with the conscious purpose of increasing what, which acts as a limiting factor on populations in general?

niche

density dependent limitation

containing capacity

carrying capacity

Overcoming Density-Dependent Regulation Humans are unique in their ability to alter their environment with the conscious purpose of increasing its carrying capacity. This ability is a major factor responsible for human population growth and a way of overcoming density-dependent growth regulation. Much of this ability is related to human intelligence, society, and communication. Humans can construct shelter to protect them from the elements and have developed agriculture and domesticated animals to increase their food supplies. In addition, humans use language to communicate this technology to new generations, allowing them to improve upon previous accomplishments. Other factors in human population growth are migration and public health. Humans originated in Africa, but have since migrated to nearly all inhabitable land on the Earth. Public health, sanitation, and the use of antibiotics and vaccines have decreased the ability of infectious disease to limit human population growth. In the past, diseases such as the bubonic plaque of the fourteenth century killed between 30 and 60 percent of Europe’s population and reduced the overall world population by as many as 100 million people. Today, the threat of infectious disease, while not gone, is certainly less severe. According to the World Health Organization, global death from infectious disease declined from 16.4 million in 1993 to 14.7 million in 1992. To compare to some of the epidemics of the past, the percentage of the world's population killed between 1993 and 2002 decreased from 0.30 percent of the world's population to 0.24 percent. Thus, it appears that the influence of infectious disease on human population growth is becoming less significant.

A desmosome is a cell structure that anchors the ends of what fibers together?

smooth muscle

skeletal muscle

controllable muscle

cardiac muscle

30.5 Applications of Atomic Excitations and De-Excitations 30. Figure 30.39 shows the energy-level diagram for neon. (a) Verify that the energy of the photon emitted when neon goes from its metastable state to the one immediately below is equal to 1.96 eV. (b) Show that the wavelength of this radiation is 633 nm. (c) What wavelength is emitted when the neon makes a direct transition to its ground state? 31. A helium-neon laser is pumped by electric discharge. What wavelength electromagnetic radiation would be needed to pump it? See Figure 30.39 for energy-level information. Ruby lasers have chromium atoms doped in an aluminum oxide crystal. The energy level diagram for chromium in a ruby is shown in Figure 30.64. What wavelength is emitted by a ruby laser?.

How much space a surface covers is known as what?

Height

Flatness

Lenght

area

The area of a surface is how much space it covers. It’s easy to calculate the area of a surface if it has a regular shape, such as the blue rectangle in the sketch below. You simply substitute measurements of the surface into the correct formula. To find the area of a rectangular surface, use this formula:.

What do aquatic arthropods use to exchange gases?

diaphragm

lungs

pores

gills

Aquatic arthropods use gills to exchange gases. These gills have a large surface area in contact with the water, so they can absorb more oxygen.

What kind of rays can travel thousands of meters through air and can penetrate and damage cells deep inside the body?

plasma rays

x-rays

cosmic rays

gamma rays

Alpha particles can travel only a few centimeters through air. They can burn the skin but not penetrate it. Beta particles can travel up to a meter through air. They can penetrate and damage skin. Gamma rays can travel thousands of meters through air. They can penetrate and damage cells deep inside the body.

Of the three types of skeleton designs - hydrostatic skeletons, exoskeletons, and endoskeletons - which do humans possess?

exoskeleton

none of the above

hydrostatic skeleton

endoskeleton

CHAPTER SUMMARY 38.1 Types of Skeletal Systems The three types of skeleton designs are hydrostatic skeletons, exoskeletons, and endoskeletons. A hydrostatic skeleton is formed by a fluid-filled compartment held under hydrostatic pressure; movement is created by the muscles producing pressure on the fluid. An exoskeleton is a hard external skeleton that protects the outer surface of an organism and enables movement through muscles attached on the inside. An endoskeleton is an internal skeleton composed of hard, mineralized tissue that also enables movement by attachment to muscles. The human skeleton is an endoskeleton that is composed of the axial and appendicular skeleton. The axial skeleton is composed of the bones of the skull, ossicles of the ear, hyoid bone, vertebral column, and ribcage. The skull consists of eight cranial bones and 14 facial bones. Six bones make up the ossicles of the middle ear, while the hyoid bone is located in the neck under the mandible. The vertebral column contains 26 bones, and it surrounds and protects the spinal cord. The thoracic cage consists of the sternum, ribs, thoracic vertebrae, and costal cartilages. The appendicular skeleton is made up of the limbs of the upper and lower limbs. The pectoral girdle is composed of the clavicles and the scapulae. The upper limb contains 30 bones in the arm, the forearm, and the hand. The pelvic girdle attaches the lower limbs to the axial skeleton. The lower limb includes the bones of the thigh, the leg, and the foot.

What regulates homeostasis and basic survival behaviors?

cell membrane

hippocampus

mitosis

hypothalamus

What device changes kinetic energy to electrical energy through electromagnetic induction?

real generator

due generator

Emission generator

electric generator

An electric generator is a device that changes kinetic energy to electrical energy through electromagnetic induction. Electromagnetic induction is the process of generating electric current with a magnetic field. It occurs when a magnetic field and an electric conductor, such as a coil of wire, move relative to one another.

What are two nonliving things that all living things need for survival?

methane

sunlight

calcium

water and air

The fight or flight response involves what system?

voluntary nervous system

functional nervous system

cellular nervous system

autonomic nervous system

Figure 15.1 Fight or Flight? Though the threats that modern humans face are not large predators, the autonomic nervous system is adapted to this type of stimulus. The modern world presents stimuli that trigger the same response. (credit: Vernon Swanepoel).

How many types of galaxies are there?

two

one

five

three

Galaxies are divided into three types, according to shape. There are spiral galaxies, elliptical galaxies, and irregular galaxies. Spiral galaxies are a rotating disk of stars and dust. In the center is a dense bulge of material. Several arms spiral out from the center. Spiral galaxies have lots of gas and dust and many young stars. Figure below shows a spiral galaxy from the side. You can see the disk and central bulge.

Skin color is controlled by genes but also influenced by exposure to what?

makeup

food

precipitation

sunlight

Genes play an important role in determining an organism's traits. However, for many traits, phenotype is influenced by the environment as well. For example, skin color is controlled by genes but also influenced by exposure to sunlight. You can see the effect of sunlight on skin in Figure below .

Higher temperatures increase the rate of reaction in a lot of chemical reactions because they increase the frequency of what interaction between reactant particles?

waves

electric

explosions

collisions

Raising the temperature of a chemical reaction usually results in a higher rate of reaction. When the reactant particles are heated, they move faster and faster. This results in a greater frequency of collisions. A more important effect of the temperature increase is that the collisions occur with a greater force and are thus more likely to surmount the activation energy barrier and go on to form products. Increasing the temperature of a reaction increases the number of effective collisions between reacting particles, so the reaction rate increases.

Knees and elbows are examples of what part of the skeletal system?

nerves

cartilage

muscles

joints

As you age, you might start noticing pain in your knees or elbows. These are examples of joints. Joints are the part of the skeletal system that connect your bones. Joint pain is a common problem as people age.

Einstein’s equation helps scientists understand what happens in nuclear reactions and why they produce so much what?

hydrogen

light

food

energy

Einstein’s equation helps scientists understand what happens in nuclear reactions and why they produce so much energy. When the nucleus of a radioisotope undergoes fission or fusion in a nuclear reaction, it loses a tiny amount of mass. What happens to the lost mass? It isn’t really lost at all. It is converted to energy. How much energy? E = mc 2 . The change in mass is tiny, but it results in a great deal of energy.

Ovulation is the release of an egg from the what?

vagina

fallopian tubes

cervix

ovary

Ovulation, the release of an egg from the ovary, occurs at about the midpoint of the cycle. This would be around day 14 of a 28 day cycle. The egg is swept into the fallopian tube. If sperm is present, fertilization may occur. As sperm can only survive in the fallopian tube for up to a few days, fertilization can only occur within those few days post-ovulation.

The process in which the nucleus divides is called what?

cytokinesis

meiosis

epistasis

mitosis

In eukaryotic cells, the nucleus divides before the cell itself divides. The process in which the nucleus divides is called mitosis. Before mitosis occurs, a cell’s DNA is replicated. This is necessary so that each daughter cell will have a complete copy of the genetic material from the parent cell. How is the replicated DNA sorted and separated so that each daughter cell gets a complete set of the genetic material? To understand how this happens, you need to know more chromosomes.

What is used to recrystallize excess dissolved solute in a supersaturated solution?

fertilizer crystal

starter crystal

energy crystal

seed crystal

Some solutes, such as sodium acetate, do not recrystallize easily. Suppose an exactly saturated solution of sodium acetate is prepared at 50°C. As it cools back to room temperature, no crystals appear in the solution, even though the solubility of sodium acetate is lower at room temperature. A supersaturated solution is a solution that contains more than the maximum amount of solute that is capable of being dissolved at a given temperature. The recrystallization of the excess dissolved solute in a supersaturated solution can be initiated by the addition of a tiny crystal of solute, called a seed crystal. The seed crystal provides a nucleation site on which the excess dissolved crystals can begin to grow. Recrystallization from a supersaturated solution is typically very fast.

Our bodies use what, primarily in the form of glucose, for our immediate energy needs - although they are not as energy dense or capable of long-term storage as lipids?

proteins

enzymes

electrolytes

carbohydrates

Opening Essay On July 11, 2003, the Food and Drug Administration amended its food labeling regulations to require that manufacturers list the amount of trans fatty acids on Nutrition Facts labels of foods and dietary supplements, effective January 1, 2006. This amendment was a response to published studies demonstrating a link between the consumption of trans fatty acids and an increased risk of heart disease. Trans fatty acids are produced in the conversion of liquid oils to solid fats, as in the creation of many commercial margarines and shortenings. They have been shown to increase the levels of low-density lipoproteins (LDLs)—complexes that are often referred to as bad cholesterol—in the blood. In this chapter, you will learn about fatty acids and what is meant by a trans fatty acid, as well as the difference between fats and oils. You will also learn what cholesterol is and why it is an important molecule in the human body. Fats and oils, found in many of the foods we eat, belong to a class of biomolecules known as lipids. Gram for gram, they pack more than twice the caloric content of carbohydrates: the oxidation of fats and oils supplies about 9 kcal of energy for every gram oxidized, whereas the oxidation of carbohydrates supplies only 4 kcal/g. Although the high caloric content of fats may be bad news for the dieter, it says something about the efficiency of nature’s designs. Our bodies use carbohydrates, primarily in the form of glucose, for our immediate energy needs. Our capacity for storing carbohydrates for later use is limited to tucking away a bit of glycogen in the liver or in muscle tissue. We store our reserve energy in lipid form, which requires far less space than the same amount of energy stored in carbohydrate form. Lipids have other biological functions besides energy storage. They are a major component of the membranes of the 10 trillion cells in our bodies. They serve as.

What part of the body do ants use to detect chemicals?

eyes

thorax

fins

antennae

Some animals communicate with scent. They release chemicals that other animals of their species can smell or detect in some other way. Ants release many different chemicals. Other ants detect the chemicals with their antennae. This explains how ants are able to work together. The different chemicals that ants produce have different meanings. Some of the chemicals signal to all of the ants in a group to come together. Other chemicals warn of danger. Still other chemicals mark trails to food sources. When an ant finds food, it marks the trail back to the nest by leaving behind a chemical on the ground. Other ants follow the chemical trail to the food.

Water has the properties of cohesion and what else?

diffusion

absorption

degradation

adhesion

Water has the properties of cohesion and adhesion. Define these two properties, and explain why they occur in water.

Fitness and natural selection are parts of what theory that might describe how organisms change over time?

implementation

dessication

gravity

evolution

All of these animal behaviors are important. They help the animals get food for energy, make sure their young survive, or ensure that they, themselves, survive. Behaviors that help animals or their young survive, increase the animals’ fitness. Animals with higher fitness have a better chance of passing their genes on to the next generation. If genes control behaviors that increase fitness, the behaviors become more common in the species. This occurs through the process of evolution by natural selection.

What three forces are involved in erosion?

radiation, gravity, precipitation

water, temperature, altitude

heat, pressure, gravity

water, wind, gravity

Thermodynamics do not give us any insight into what attribute of spontaneous processes?

increase

acceleration

decrease

rate

It should be noted that just because a process is spontaneous does not mean that it occurs quickly. The rusting of iron is a spontaneous process that takes place over a long period of time. The combustion of gasoline in oxygen (also a spontaneous process) is extremely fast when provided with a spark, but gasoline can be stored in air for quite a while without spontaneously combusting. Thermodynamics predicts the direction in which a reaction will eventually proceed, but it does not tell us anything about the rate at which the reaction occurs. The rate of a reaction depends on many factors, including activation energy, temperature, concentration, and the presence or absence of a catalyst. Chemical kinetics focuses on the pathway between reactants and products, while thermodynamics considers only the difference between the initial and final states.

What is the main source of hydrocarbons?

decomposers

photosynthesis

greenhouse gases

fossil fuels

Hydrocarbons are extremely important to modern life. Their most important use is as fuels. Hydrocarbons are also used to manufacture many products including plastics. The main source of hydrocarbons is fossil fuels.