question
stringlengths
14
399
distractor3
stringlengths
1
63
distractor1
stringlengths
1
57
distractor2
stringlengths
1
62
correct_answer
stringlengths
1
67
support
stringlengths
0
3.56k
Potassium, calcium, and magnesium are considered what kind of nutrients?
major nutrients
micronutrients
minor nutrients
macronutrients
What normally prevent a positively charged particle from colliding and reacting with a positively charged nucleus, but may be overcome by kinetic energy?.
evaporation repulsions
kinetic repulsions
toxic repulsion
electrostatic repulsions
Bombarding a target of one element with high-energy nuclei or subatomic particles can create new elements. Electrostatic repulsions normally prevent a positively charged particle from colliding and reacting with a positively charged nucleus. If the positively charged particle is moving at a very high speed, however, it...
Sometimes two or more distinct phenotypes can each have their advantages and be selected for by natural selection; this is known as what?
shedding selection
extra selection
multiplying selection
diversifying selection
Diversifying Selection Sometimes two or more distinct phenotypes can each have their advantages and be selected for by natural selection, while the intermediate phenotypes are, on average, less fit. Known as diversifying selection (Figure 19.8), this is seen in many populations of animals that have multiple male forms....
Management programs based on population-regulating factors have helped prevent the extinction of many?
omnivores
abundant species
keystone species
endangered species
What basic plant structure is the site of photosynthesis?
roots
nucleus
spores
leaves
What provides the identities of the reactants and products involved in the chemical change?
atomic numbers
electron shells
genome sequence
chemical formulas
A balanced chemical equation provides a great deal of information in a very succinct format. Chemical formulas provide the identities of the reactants and products involved in the chemical change, allowing classification of the reaction. Coefficients provide the relative numbers of these chemical species, allowing a qu...
What process creates sperm?
hypothalamus
genesis
altostratus
spermatogensis
Sperm are produced in the testes in the process of spermatogenesis.
Both fluorine and lithium are highly reactive elements because of their number of what?
covalence electrons
shell electrons
positrons
valence electrons
Both fluorine and lithium are highly reactive elements because of their number of valence electrons. Fluorine will readily gain one electron and lithium will just as readily give up one electron to become more stable. In fact, lithium and fluorine will react together as shown in the Figure below . When the two elements...
Earth acts like a giant version of what device, with angular momentum along its axis and pointing at polaris, the north star?
accelerator
compass
telescope
gyroscope
Earth itself acts like a gigantic gyroscope. Its angular momentum is along its axis and points at Polaris, the North Star. But Earth is slowly precessing (once in about 26,000 years) due to the torque of the Sun and the Moon on its nonspherical shape.
Ovulation takes place in what organ and is part of the menstrual cycle?
uterus
testes
fallopian tube
ovary
The menstrual cycle includes events that take place in the ovary, such as ovulation.
Instead of a nervous system, plant responses are generally controlled by what type of molecules, which serves as chemical messengers?
sugars
receptors
enzymes
hormones
Like all organisms, plants detect and respond to stimuli in their environment. Unlike animals, plants can’t run, fly, or swim toward food or away from danger. They are usually rooted to the soil. Instead, a plant’s primary means of response is to change how it is growing. Plants also don’t have a nervous system to cont...
Asexual reproduction occurs by what process?
ripening
mating
balancing
budding
Sponges reproduce both asexually and sexually. Asexual reproduction occurs by budding. Figure below shows the sponge life cycle when sexual reproduction is involved. Adult sponges produce eggs and sperm. In many species, the same individuals produce both. However, they don’t produce eggs and sperm at the same time. As ...
What do all respiratory diseases affect?
transit exchange process
liquid exchange process
helium exchange process
gas exchange process
Reproduction Fungi reproduce sexually and/or asexually. Perfect fungi reproduce both sexually and asexually, while the so-called imperfect fungi reproduce only asexually (by mitosis). In both sexual and asexual reproduction, fungi produce spores that disperse from the parent organism by either floating on the wind or h...
What is one trait that the sponge and tarantula share?
lack of a cycle
lack of ogranic
lack of a emerge
lack of a backbone
One trait the sponge and tarantula share is lack of a backbone. In fact, they don’t have any bones at all. These are defining traits of all invertebrates. Some invertebrates have a skeleton, but it isn’t made of bone. Many other traits of invertebrates show considerable diversity.
What bonds form when pairs of electrons are shared?
dissonance bonds
ionized bonds
neutron bonds
covalent bonds
Hydrocarbons in which all carbons are connected by single bonds are called?
lipids
acids
enzymes
alkanes
Hydrocarbons are molecules that contain only carbon and hydrogen atoms. Because each carbon atom can form covalent bonds with up to four other atoms, very large and complex molecules can be formed just from these two elements. Hydrocarbons in which all carbons are connected by single bonds are known as alkanes . If a C...
What occurs when two wave crests overlap?
constructive dissonance
forth interference
constructive overlap
constructive interference
Constructive interference occurs when two wave crests overlap, doubling the wave amplitude at that location.
The length of a rectangular surface multiplied by its width is equal to what?
circumference
volume
height
area
The area of a rectangular surface is calculated as its length multiplied by its width.
What is the testing for disease in a fetus or embryo?
dynamic screening
complete screening
placental screening
prenatal screening
Consultations with human geneticists and genetic counselors are an important first step in genetic testing. They will most likely prescribe some sort of prenatal screening (see the Human Genetics: Diagnosis and Treatment (Advanced) concept). Prenatal screening (also known as prenatal diagnosis or prenatal testing) is t...
The two adrenal glands are glands located just above the what?
esophagus
intestines
lungs
kidneys
The two adrenal glands are glands located just above the kidneys. Each adrenal gland has an outer layer (cortex) and inner layer (medulla) that secrete different hormones. The hormone adrenaline is secreted by the inner layer. It prepares the body to respond to emergencies. For example, it increases the amount of oxyge...
What is the term for the number of waves that pass a fixed point in a given amount of time?
wave velocity
wave speed
wave distance
wave frequency
Wave frequency is the number of waves that pass a fixed point in a given amount of time. Higher frequency waves have more energy. Wave speed is calculated as wavelength multiplied by wave frequency. Wave speed is affected by the medium through which a wave travels.
The migration of what familiar coastal landform involves saltation and gravity?
rivers
volcanos
lakes
sand dunes
Once a sand dune forms, it may slowly migrate over the land. The wind moves grains of sand up the gently sloping side of the dune. This is done by saltation. When the sand grains reach the top of the dune, they slip down the steeper side. The grains are pulled by gravity. The constant movement of sand up and over the d...
The procedure known as angioplasty is used when what part of the circulatory system is clogged?
the spinal cord
lungs
the heart
blood vessel
When a blood vessel gets clogged, there is no medical equivalent of "Drano" that will clear it out. There is, however, a procedure known as angioplasty. A thin tube with a balloon is threaded through the blood vessels. Once in place, the balloon is inflated to compress the clog against the artery wall.
What type of maps detail detail the types and locations of rocks found in an area?
gnomic maps
contour maps
polar maps
geologic maps
Geologic maps detail the types and locations of rocks found in an area.
What is another term for the voice box?
optical nerve
pharynx
pancreas
larynx
The larynx , also called the "voice box," is found just below the pharynx. Your voice comes from your larynx. Air from the lungs passes across thin tissues in the larynx and produces sound.
The proximity of the axillary buds to the apical bud is partly responsible for their what?
development
germination
growth
dormancy
How do the vast majority of fish reproduce?
cloning
by budding
asexually
sexually
Nearly all fish reproduce sexually, and most species have separate sexes. Those without separate sexes avoid self-fertilization by producing sperm and eggs at different times. Each fish typically produces a large number of gametes. In most fish species, fertilization takes place externally. These fish are oviparous . E...
What is the quantity of force multiplied by the time it is applied called?
gravity
velocity
density
impulse
The quantity of force multiplied by the time it is applied is called impulse.
Diphenylamine acts as a stabilizer for certain types of what?
proteins
toxins
enzymes
explosives
Amines serve a wide variety of uses. Diphenylamine acts as a stabilizer for certain types of explosives. Amines are found as components in some lubricating materials, in developers, and are a part of waterproofing textiles. Some amines, such as novocaine, are used as anesthetics. Many pharmaceutical compounds contain a...
Behind the pupil, a single lens focuses light on a layer of what?
electrons
photons
chloroplasts
photoreceptors
Why is the root cap continuously replaced in plants?
due to rubbing
due to growth
due to pressure
damage through pushing
Root Growth and Anatomy Root growth begins with seed germination. When the plant embryo emerges from the seed, the radicle of the embryo forms the root system. The tip of the root is protected by the root cap, a structure exclusive to roots and unlike any other plant structure. The root cap is continuously replaced bec...
Aquatic biomes are determined mainly by distance from shore and what other factor?
species populations
water temperature
salinity
depth of water
Aquatic biomes are determined mainly by depth of water and distance from shore. They include freshwater and marine biomes.
Who is said to have dropped two objects of different masses from the tower of pisa?
newton
darwin
copernicus
galileo
Galileo’s Experiment Galileo is said to have dropped two objects of different masses from the Tower of Pisa. He measured how long it took each to reach the ground. Since stopwatches weren’t readily available, how do you think he measured their fall time? If the objects were the same size, but with different masses, wha...
What determines the length and thickness of dna chromosomes?
number of chromosomes
degree of rna coiling
type of dna
degree of dna coiling
The degree of DNA coiling determines whether the chromosome strands are short and thick or long and thin. Between cell divisions, the DNA in chromosomes is more loosely coiled and forms long thin strands called chromatin . DNA is in this uncoiled form during the majority of the cell cycle, making the DNA available to t...
What type of gas is used to fill glass tubes of lighted signs?
natural
synthetic
inert
noble
Noble gases are also used to fill the glass tubes of lighted signs like the one in the Figure below . Although noble gases are chemically nonreactive, their electrons can be energized by sending an electric current through them. When this happens, the electrons jump to a higher energy level. When the electrons return t...
What does fog consist of?
carbon monoxide
helium
steam
droplets of water
Both of these photos show the famous Golden Gate Bridge near San Francisco, California. The pictures were taken from about the same point of view, but they look very different. In the picture on the left, the deck of the bridge is almost completely hidden by a thick layer of fog. In the picture on the right the fog has...
Spiders use the hydrostatic pressure generated by an open type of what anatomical system to extend their legs?
vascular
respiratory
pulmonary
circulatory
The normal respiratory rate per minute in adult humans is?
18-24 breaths
6-12 breaths
0-6 breaths
12-18 breaths
Respiratory Rate and Control of Ventilation Breathing usually occurs without thought, although at times you can consciously control it, such as when you swim under water, sing a song, or blow bubbles. The respiratory rate is the total number of breaths, or respiratory cycles, that occur each minute. Respiratory rate ca...
Where is glycogen created and stored in the body?
Sore muscle
extracts and muscles
Healing Muscles
liver and muscles
Connections of Other Sugars to Glucose Metabolism Glycogen, a polymer of glucose, is an energy storage molecule in animals. When there is adequate ATP present, excess glucose is shunted into glycogen for storage. Glycogen is made and stored in both liver and muscle. The glycogen will be hydrolyzed into glucose monomers...
When we neutralize a weak base with a strong acid, the product is ________ containing the conjugate acid of the weak base.
water
an electron
an ion
salt
Salts of Weak Bases and Strong Acids When we neutralize a weak base with a strong acid, the product is a salt containing the conjugate acid of the weak base. This conjugate acid is a weak acid. For example, ammonium chloride, NH4Cl, is a salt formed by the reaction of the weak base ammonia with the strong acid HCl: NH ...
What is the main component of milk?
proteins
fat
lactose
water
A: Homogenized milk is a colloid. The particles in the milk are large enough to see—that’s why milk is white instead of clear like water, which is the main component of milk. However, the particles are not large enough to settle out of the mixture.
Stomata are the main avenues of transpiration, the evaporative loss of water from what?
stalks
fruits
roots
leaves
What is a form of matter that has a definite shape and volume?
liquid
plasma
gas
solid
A solid is a form of matter that has a definite shape and volume. The shape of a solid does not change if it is transferred from one container to another. The particles of a solid are packed tightly together in fixed positions, usually in an orderly arrangement. Solids are almost completely incompressible, meaning that...
What type of energy is stored in the nuclei of atoms?
heat energy
light energy
radioactive energy
nuclear energy
7. Nuclear energy is energy that is stored in the nuclei of atoms because of the strong forces that hold the nucleus together. The energy can be released in nuclear power plants by splitting nuclei apart. It is also released when unstable (radioactive) nuclei break down, or decay.
Providing evidence of their ancestry, some species of what legless animals retain vestigial pelvic and limb bones?
whales
dolphins
sharks
snakes
What happens when more glucose is present than the proteins can handle, in the body?
forms urine
cultured as urine
metamorphosed as urine
excreted as urine
An example of this process occurs in the kidney. Glucose, water, salts, ions, and amino acids needed by the body are filtered in one part of the kidney. This filtrate, which includes glucose, is then reabsorbed in another part of the kidney. Because there are only a finite number of carrier proteins for glucose, if mor...
What are most protist diseases in humans caused by?
ticks
eukaryots
lice
protozoa
Most protist diseases in humans are caused by protozoa. Protozoa make humans sick when they become human parasites.
Transporting blood is the main job of the heart and what?
lymphatic system
bones
areolas
blood vessels
Transporting blood is the main job of the heart and blood vessels.
What occurs when the amount of solute dissolved exceeds the solubility of the solute?
stimulation
salination
absorption
saturation
When the amount of solute dissolved exceeds the solubility of the solute. Occurs when a solution is saturated and the temperature slowly drops.
What are cyclins made up of?
steroids
enzymes
group of sugars
group of proteins
The cell cycle is controlled by a number of protein-controlled feedback processes. Two types of proteins involved in the control of the cell cycle are kinases and cyclins . Cyclins activate kinases by binding to them, specifically they activate cyclin-dependent kinases (CDK) . Cyclins comprise a group of proteins that ...
What do ferns use in place of seeds to reproduce?
toxins
glands
atoms
spores
Seedless vascular plants include plants such as ferns. You can see a fern in Figure below . Ferns reproduce with spores instead of seeds. The black dots on the back of the fern leaf in Figure below are spores.
Water affects the availability of what important element in aquatic environments and in flooded soils?
carbon dioxide
carbon
nitrogen
oxygen
Fuels according to the law of what, can never actually be “consumed”; it can only be changed from one form to another?
difference of energy
use of energy
expansion of energy
conservation of energy
Fuels According to the law of conservation of energy, energy can never actually be “consumed”; it can only be changed from one form to another. What is consumed on a huge scale, however, are resources that can be readily converted to a form of energy that is useful for doing work. As you will see in Chapter 18 "Chemica...
The ability of matter to burn is called?
unpredictability
solubility
eccentricity
flammability
Flammability is the ability of matter to burn. Wood is flammable; iron is not. When wood burns, it changes to ashes, carbon dioxide, water vapor, and other gases. After burning, it is no longer wood.
Uncontrolled cell growth can lead to tumors and what disease?
kidney failure
vascular disease
cirrhosis
cancer
10.4 | Cancer and the Cell Cycle By the end of this section, you will be able to: • Describe how cancer is caused by uncontrolled cell growth • Understand how proto-oncogenes are normal cell genes that, when mutated, become oncogenes • Describe how tumor suppressors function • Explain how mutant tumor suppressors cause...
Video and audio signals are broadcast on these?
thermal waves
mechanical waves
radiation waves
electromagnetic waves
video and audio signals broadcast on electromagnetic waves.
In a tropical rainforest, where are ferns common?
canopy
forrest floor
emergent
understory
Photography by Kat. Ferns are common in the understory of the tropical rainforest . CC BY 2.0.
Which metalloids are found in the nitrogen group?
sulfur and polonium
polonium and antimony
selenium and antimony
arsenic and antimony
Group 15 is called the nitrogen group. The metalloids in this group are arsenic and antimony. Group 15 also contains two nonmetals and one metal.
What kind of family is haumea part of?
orbital family
eoan family
a moclobemide family
a collisional family
Haumea is part of a collisional family. This is a group of astronomical objects that formed from an impact. This family has Haumea, its two moons, and five more objects. All of these objects are thought to have formed from a collision very early in the formation of the solar system.
The db gene encodes the which receptor?
estrogen
glucose
opioid
leptin
How many main types of diabetes are there?
six
three
one
two
There are two main types of diabetes, type 1 diabetes and type 2 diabetes. Type 1 diabetes makes up about 5-10% of all cases of diabetes in the United States. Type 2 diabetes accounts for most of the other cases. Both types of diabetes are more likely in people that have certain genes. Having a family member with diabe...
What organ is similar to a lymph node but is much larger and filters blood instead of lymph?
bone
kidney
liver
spleen
Figure 42.21 The spleen is similar to a lymph node but is much larger and filters blood instead of lymph. Blood enters the spleen through arteries and exits through veins. The spleen contains two types of tissue: red pulp and white pulp. Red pulp consists of cavities that store blood. Within the red pulp, damaged red b...
What is the process of converting atmospheric nitrogen to ammonia called?
oral fixation
atmospheric fixation
ammonia fixation
nitrogen fixation
Phospholipids and some proteins move laterally within what?
particles
liquids
nuclei
membrane
What changes encoded waves which are being broadcast into sounds?
band receivers
transmitters
amplifiers
radio receivers
In radio broadcasts, sounds are encoded in radio waves by changing either the amplitude (AM) or frequency (FM) of the waves. The encoded waves are broadcast from a tower and changed back to sounds by radio receivers.
When the oval window vibrates, it causes what else to vibrate as well?
hammer and anvil
cilia
timpani
the cochlea
The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny “hairs,...
When changes in the genes of a species result in a new species, the process is called what?
similar evolution
Classic Evolution
simple evolution
biological evolution
Changes in the genes of a species may result in a new species. This is biological evolution.
What happens if a person doesn’t take in enough water to replace the water lost in sweat?
relaxation
diarrhea
fatigue
dehydration
The boy in Figure below is taking a water break while playing outside on a hot day. If he doesn’t take in enough water to replace the water lost in sweat, he may become dehydrated. Symptoms of dehydration include dry mouth, headache, and dizziness. Dehydration can be very serious. It can even cause death.
How does the atomic number change during beta emission?
decreases by one
stays the same
increases by two
increases by one
Beta (β) decay is a more complicated process. Unlike the α-emission, which simply expels a particle, the β-emission involves the transformation of a neutron in the nucleus to a proton and an electron. The electron is then ejected from the nucleus. In the process, the atomic number increases by one while the atomic weig...
What is the most widely distributed organism around?
microbes
viruses
cockroaches
phages
Viruses can be found almost anywhere there is life, including living within prokaryotes. A phage is a virus that infects prokaryotes. Phages are estimated to be the most widely distributed and diverse entities in the biosphere, even more numerous than prokaryotic organisms. Phages can be found everywhere their hosts ar...
On a topographic map, what is the term for a line of equal elevation?
aurora line
latitude line
crater line
contour line
The topography of a region can be shown on a map. Topographic maps represent geographical features, such as hills and valleys. Topographic maps use contour lines to show geographical features. A contour line is a line of equal elevation. If you walk along a contour line, you will not go uphill or downhill. Topographic ...
Where does the stratosphere get most of its heat?
volcanoes
time
earth
sun
Air temperature in the stratosphere layer increases with altitude. Why? The stratosphere gets most of its heat from the Sun. Therefore, it’s warmer closer to the Sun. The air at the bottom of the stratosphere is cold. The cold air is dense, so it doesn’t rise. As a result, there is little mixing of air in this layer.
What source of ocean pollution kills animals by coating them?
chemical spill
plants spill
grain spill
oil spill
Oil spills are another source of ocean pollution. To get at oil buried beneath the seafloor, oil rigs are built in the oceans. These rigs pump oil from beneath the ocean floor. Huge ocean tankers carry oil around the world. If something goes wrong with a rig on a tanker, millions of barrels of oil may end up in the wat...
What is the name of pluto's moon?
Europa
Phobos
Titania
charon
Pluto and its moon, Charon, are actually two objects.
What type of bond generally forms between a metal and non-metal?
horizontal
soluble
unbreakable
ionic
Ionic bonds form only between metals and nonmetals. That’s because metals “want” to give up electrons, and nonmetals “want” to gain electrons. Find sodium (Na) in the Figure below . Sodium is an alkali metal in group 1. Like all group 1 elements, it has just one valence electron. If sodium loses that one electron, it w...
What's the name for an atom that has gained or lost an electron?
neutrino
an photon
isotope
an ion
Atoms cannot only gain extra electrons. They can also lose electrons. In either case, they become ions . Ions are atoms that have a positive or negative charge because they have unequal numbers of protons and electrons. If atoms lose electrons, they become positive ions, or cations. If atoms gain electrons, they become...
Light is scattered from what in our atmosphere?
ions
matter
particles
molecules
Light is scattered from the molecules in our atmosphere.
What refers to the union of a male and female of the same species for reproduction?
behavior
asexual reproduction
dating
mating
Mating refers to the union of a male and female of the same species for reproduction. The relationship between mates varies by species. Adults may have many mates, or they may mate with just one individual. Mates may stay together only while mating. Or they may stay together for an entire breeding season or even for li...
Tree sap enclosing an organism in amber or an organism preserved in tar or ice are actually examples of what?
fuels
bones
corals
fossils
Fossils may form in other ways. With complete preservation, the organism doesn't change much. As pictured below ( Figure below ), tree sap may cover an organism and then turn into amber . The original organism is preserved so that scientists might be able to study its DNA. Organisms can also be completely preserved in ...
Which theory states that the characteristics of living things are controlled by genes?
order theory
string theory
creationism
gene theory
The gene theory states that the characteristics of living things are controlled by genes.
What does the secondary oocyte have the most of from the original cell?
electron
rna
bacteria
cytoplasm
Beginning in puberty, each month one of the follicles and its primary oocyte starts to mature (also see Figure below ). The primary oocyte resumes meiosis and divides to form a secondary oocyte and a smaller cell, called a polar body. Both the secondary oocyte and polar body are haploid cells. The secondary oocyte has ...
Kangaroos, koala and opossums are part of what group?
monotremes
primates
cephalopods
marsupials
Marsupials. Marsupials include the kangaroo, koala, and opossum.
What term refers to a group of individuals of the same species that live in the same area and is the unit of natural selection, adaptation, and microevolution?
community
ecosystem
taxonomy
population
A population is a group of individuals of the same species that live in the same area. The population is the unit of natural selection, adaptation, and microevolution. In ecology, how large a population is and how quickly it is growing are often used as measures of a species’ health.
What larger theory is einstein's equation part of?
law of relativity
excess of relativity
cycle of relativity
theory of relativity
Einstein’s equation is part of a larger theory called the theory of relativity. It is concerned with concepts such as motion and forces as well as mass and energy. Motion and forces are the focus of succeeding chapters.
Low yields of nitric oxide, no, form when heating nitrogen and oxygen together. no also forms when lightning passes through air during this?
tornadoes
tidal waves
snowstorms
thunderstorms
Low yields of nitric oxide, NO, form when heating nitrogen and oxygen together. NO also forms when lightning passes through air during thunderstorms. Burning ammonia is the commercial method of preparing nitric oxide. In the laboratory, the reduction of nitric acid is the best method for preparing nitric oxide. When co...
Scientists that study dolphins and other life in the ocean are called what?
ocean biologists
marine geneticists
sea biologists
marine biologists
Dolphins are living organisms, so studying them is part of the life sciences. The life sciences, however, are broken down into many fields. Scientists that study dolphins and other life in the ocean are called marine biologists.
What is the scientific term for the act of eating or feeding?
swallowing
secretion
excretion
ingestion
The collision of what is responsible for massive earthquakes?
fault lines
weather fronts
tidal currents
two continents
The collision of two continents also creates massive earthquakes. Many earthquakes happen in the region in and around the Himalayan Mountains. The 2001 Gujarat, India earthquake is responsible for about 20,000 deaths, with many more people injured or made homeless ( Figure below ).
Proteins are one of four classes of what type of compounds?
synthesized
hormonal
genetic
biochemical
Proteins are one of four classes of biochemical compounds. Proteins contain carbon, hydrogen, oxygen, nitrogen, and sulfur.
What is the term for a fold that arches upward?
tailplane
tailslide
underlain
anticline
An anticline is a fold that arches upward. The rocks dip away from the center of the fold ( Figure below ). The oldest rocks are found at the center of an anticline. The youngest rocks are draped over them at the top of the structure. When upward folding rocks form a circular structure, that structure is called a dome ...
Under certain conditions, electric current causes what type of field?
seismic
light
kinetic
magnetic
Electricity and magnetism are inextricably linked. Under certain conditions, electric current causes a magnetic field. Under other conditions, a magnetic field can cause an electric current. A moving charged particle creates a magnetic field around it. Additionally, when a moving charged particle moves through a differ...
What is the most complex organ in the human body?
muscular
heart
liver
brain
The human brain is an amazing organ. It is the most complex organ in the human body. By adulthood, the brain weighs about 3 pounds and consists of billions of neurons. All those cells need a lot of energy. In fact, the adult brain uses almost a quarter of the total energy used by the body!.
What is a soft connective tissue inside pores and cavities in spongy bone?
synovial tissue
cartilage
collagen
bone marrow
Bone marrow is a soft connective tissue inside pores and cavities in spongy bone. Bone marrow makes blood cells.
What is another term for chemical messenger molecules?
acids
pheromones
enzymes
hormones
an endocrine system with glands that secrete chemical messenger molecules called hormones.
The alimentary canal is associated with what organ system?
cardiovascular
respiratory
nervous
digestive
Neural Controls The walls of the alimentary canal contain a variety of sensors that help regulate digestive functions. These include mechanoreceptors, chemoreceptors, and osmoreceptors, which are capable of detecting mechanical, chemical, and osmotic stimuli, respectively. For example, these receptors can sense when th...
Which organisms capture light energy and convert it to chemical energy inside their cell?
sporozoans
chloroplasts
pores
phototrophs
Phototrophs are organisms that capture light energy and convert it to chemical energy inside their cell. Most phototrophs are the autotrophs that perform photosynthesis, which are also known as photoautotrophs. These organisms have the ability to fix carbon from carbon dioxide into organic compounds, such as glucose. C...
Specific scents are often associated with what?
instincts
pheromones
behaviors
memories
Specific scents are often associated with our memories of places and events. That's because scents are more novel or specific than shapes or other things you might see. So an odor similar to that of your grandmother's kitchen or pantry might be more quickly associated with your memories of that place than a similar sig...
Microwave ovens use radiation to provide food with what kind of energy?
mechanical
magnetic
vibrational
heat
Microwave ovens operate by emitting microwave radiation, which is primarily absorbed by water molecules in food. The absorbed radiation is converted to heat through rapid oscillations of polar water molecules, 28.
What are usually planted in rows with bare soil in between the rows?
trees
corn
beans
crops
The problem doesn’t stop with plowing. Crops are usually planted in rows with bare soil in between the rows. In places where crops grow only during part of the year, the land may be bare for a few months.
Name the type of system that a jellyfish does not have?
hereditary
nervous
reproductive
circulatory
The half-life of titanium-44 is 60.0 y. A sample of titanium contains 0.600 g of titanium-44. How much remains after 100.0 y?.