A&P Reading Questions

Explain why CH4 is one of the most common molecules found in nature. Are the bonds between the atoms ionic or covalent?

A carbon atom has four electrons in its valence shell. According to the octet rule, it will readily participate in chemical reactions that result in its valence shell having eight electrons. Hydrogen, with one electron, will complete its valence shell with two. Electron sharing between an atom of carbon and four atoms of hydrogen meets the requirements of all atoms. The bonds are covalent because the electrons are shared: although hydrogen often participates in ionic bonds, carbon does not because it is highly unlikely to donate or accept four electrons.

For whom would an appreciation of the structural characteristics of the human heart come more easily: an alien who lands on Earth, abducts a human, and dissects his heart, or an anatomy and physiology student performing a dissection of the heart on her very first day of class? Why?

A student would more readily appreciate the structures revealed in the dissection. Even though the student has not yet studied the workings of the heart and blood vessels in her class, she has experienced her heart beating every moment of her life, has probably felt her pulse, and likely has at least a basic understanding of the role of the heart in pumping blood throughout her body. This understanding of the heart's function (physiology) would support her study of the heart's form (anatomy).

Once dietary fats are digested and absorbed, why can they not be released directly into the bloodstream?

All lipids are hydrophobic and unable to dissolve in the watery environment of blood. They are packaged into lipoproteins, whose outer protein envelope enables them to transport fats in the bloodstream.

Name 3 reasons to study anatomy and physiology

An understanding of anatomy and physiology is essential for any career in the health professions. It can also help you make choices that promote your health, respond appropriately to signs of illness, make sense of health-related news, and help you in your roles as a parent, spouse, partner, friend, colleague, and caregiver.

Which medical imaging technique is most dangerous to use repeatedly, and why?

CT scanning subjects patients to much higher levels of radiation than X-rays, and should not be performed repeatedly.

Name the six levels of organization of the human body.

Chemical, cellular, tissue, organ, organ system, organism.

Explain in your own words why DNA replication is said to be "semiconservative"?

DNA replication is said to be semiconservative because, after replication is complete, one of the two parent DNA strands makes up half of each new DNA molecule. The other half is a newly synthesized strand. Therefore, half ("semi") of each daughter DNA molecule is from the parent molecule and half is a new molecule.

Why is it important that DNA replication take place before cell division? What would happen if cell division of a body cell took place without DNA replication, or when DNA replication was incomplete?

During cell division, one cell divides to produce two new cells. In order for all of the cells in your body to maintain a full genome, each cell must replicate its DNA before it divides so that a full genome can be allotted to each of its offspring cells. If DNA replication did not take place fully, or at all, the offspring cells would be missing some or all of the genome. This could be disastrous if a cell was missing genes necessary for its function and health.

Identify three different ways that growth can occur in the human body.

Growth can occur by increasing the number of existing cells, increasing the size of existing cells, or increasing the amount of non-cellular material around cells.

How does temperature affect diffusion rate, and why?

Higher temperatures speed up diffusion because molecules have more kinetic energy at higher temperatures.

Could two atoms of oxygen engage in ionic bonding? Why or why not?

Identical atoms have identical electronegativity and cannot form ionic bonds. Oxygen, for example, has six electrons in its valence shell. Neither donating nor accepting the valence shell electrons of the other will result in the oxygen atoms completing their valence shells. Two atoms of the same element always form covalent bonds.

In which direction would an MRI scanner move to produce sequential images of the body in the frontal plane, and in which direction would an MRI scanner move to produce sequential images of the body in the sagittal plane?

If the body were supine or prone, the MRI scanner would move from top to bottom to produce frontal sections, which would divide the body into anterior and posterior portions, as in "cutting" a deck of cards. Again, if the body were supine or prone, to produce sagittal sections, the scanner would move from left to right or from right to left to divide the body lengthwise into left and right portions.

AB+CD→AD+BE Is this a legitimate example of an exchange reaction? Why or why not?

It is not. An exchange reaction might be AB+CD→AC+BD or AB+CD→AD+BC. In all chemical reactions, including exchange reactions, the components of the reactants are identical to the components of the products. A component present among the reactants cannot disappear, nor can a component not present in the reactants suddenly appear in the products.

During a party, Eli loses a bet and is forced to drink a bottle of lemon juice. Not long thereafter, he begins complaining of having difficulty breathing, and his friends take him to the local emergency room. There, he is given an intravenous solution of bicarbonate. Why?

Lemon juice, like any acid, releases hydrogen ions in solution. As excessive H+ enters the digestive tract and is absorbed into blood, Eli's blood pH falls below 7.35. Recall that bicarbonate is a buffer, a weak base that accepts hydrogen ions. By administering bicarbonate intravenously, the emergency department physician helps raise Eli's blood pH back toward neutral.

Magnesium is an important element in the human body, especially in bones. Magnesium's atomic number is 12. Is it stable or reactive? Why? If it were to react with another atom, would it be more likely to accept or to donate one or more electrons?

Magnesium's 12 electrons are distributed as follows: two in the first shell, eight in the second shell, and two in its valence shell. According to the octet rule, magnesium is unstable (reactive) because its valence shell has just two electrons. It is therefore likely to participate in chemical reactions in which it donates two electrons.

If the disaccharide maltose is formed from two glucose monosaccharides, which are hexose sugars, how many atoms of carbon, hydrogen, and oxygen does maltose contain and why?

Maltose contains 12 atoms of carbon, but only 22 atoms of hydrogen and 11 atoms of oxygen, because a molecule of water is removed during its formation via dehydration synthesis.

What materials can easily diffuse through the lipid bilayer, and why?

Only materials that are relatively small and nonpolar can easily diffuse through the lipid bilayer. Large particles cannot fit in between the individual phospholipids that are packed together, and polar molecules are repelled by the hydrophobic/nonpolar lipids that line the inside of the bilayer.

Oxygen, whose atomic number is eight, has three stable isotopes: 16O, 17O, and 18O. Explain what this means in terms of the number of protons and neutrons.

Oxygen has eight protons. In its most abundant stable form, it has eight neutrons, too, for a mass number of 16. In contrast, 17O has nine neutrons, and 18O has 10 neutrons.

How is PET used in chemotherapy?

PET scans can indicate how patients are responding to chemotherapy.

Compare and contrast lysosomes with peroxisomes: name at least two similarities and one difference.

Peroxisomes and lysosomes are both cellular organelles bound by lipid bilayer membranes, and they both contain many enzymes. However, peroxisomes contain enzymes that detoxify substances by transferring hydrogen atoms and producing H2O2, whereas the enzymes in lysosomes function to break down and digest various unwanted materials.

What is the primary role of the endomembrane system?

Processing, packaging, and moving materials manufactured by the cell.

When you do a load of laundry, why do you not just drop a bar of soap into the washing machine? In other words, why is laundry detergent sold as a liquid or powder?

Recall that the greater the surface area of the reactants, the more quickly and easily they will interact. It takes energy to separate particles of a substance. Powder and liquid laundry detergents, with relatively more surface area per unit, can quickly dissolve into their reactive components when added to the water.

If a bullet were to penetrate a lung, which three anterior thoracic body cavities would it enter, and which layer of the serous membrane would it encounter first?

The bullet would enter the ventral, thoracic, and pleural cavities, and it would encounter the parietal layer of serous membrane first.

The female ovaries and the male testes are a part of which body system? Can these organs be members of more than one organ system? Why or why not?

The female ovaries and the male testes are parts of the reproductive system. But they also secrete hormones, as does the endocrine system, therefore ovaries and testes function within both the endocrine and reproductive systems.

Identify the four components of a negative feedback loop and explain what would happen if secretion of a body chemical controlled by a negative feedback system became too great.

The four components of a negative feedback loop are: stimulus, sensor, control center, and effector. If too great a quantity of the chemical were excreted, sensors would activate a control center, which would in turn activate an effector. In this case, the effector (the secreting cells) would be adjusted downward.

What is the function of magnets in an MRI?

The magnets induce tissue to emit radio signals that can show differences between different types of tissue.

What is the meaning of a mass number shown in parentheses?

The mass number is the total number of protons and neutrons in the nucleus of an atom.

What happens to the charged electroscope when a conductor is moved between its plastic sheets, and why?

The plastic sheets jump to the nail (the conductor), because the conductor takes on electrons from the electroscope, reducing the repellant force of the two sheets.

On his midsummer trek through the desert, Josh ran out of water. Why is this particularly dangerous?

The primary way that the body responds to high environmental heat is by sweating; however, sweating requires water, which comes from body fluids, including blood plasma. If Josh becomes dehydrated, he will be unable to sweat adequately to cool his body, and he will be at risk for heat stroke as his blood pressure drops too much from the loss of water from the blood plasma.

The most abundant elements in the foods and beverages you consume are oxygen, carbon, hydrogen, and nitrogen. Why might having these elements in consumables be useful?

These four elements—oxygen, carbon, hydrogen, and nitrogen—together make up more than 95 percent of the mass of the human body, and the body cannot make elements, so it is helpful to have them in consumables

Explain why ultrasound imaging is the technique of choice for studying fetal growth and development.

Ultrasonography does not expose a mother or fetus to radiation, to radiopharmaceuticals, or to magnetic fields. At this time, there are no known medical risks of ultrasonography.

In a hurry one day, you merely rinse your lunch dishes with water. As you are drying your salad bowl, you notice that it still has an oily film. Why was the water alone not effective in cleaning the bowl?

Water is a polar molecule. It has a region of weakly positive charge and a region of weakly negative charge. These regions are attracted to ions as well as to other polar molecules. Oils are nonpolar, and are repelled by water.

Explain why the smell of smoke when you are sitting at a campfire does not trigger alarm, but the smell of smoke in your residence hall does.

When you are sitting at a campfire, your sense of smell adapts to the smell of smoke. Only if that smell were to suddenly and dramatically intensify would you be likely to notice and respond. In contrast, the smell of even a trace of smoke would be new and highly unusual in your residence hall, and would be perceived as danger.

When an atom donates an electron to another atom, it becomes a. an ion b. an anion c. nonpolar d. none of the above

a. an ion

_____ reactions release energy a. catabolic b. exergonic c. decomposition d. catabolic, exergonic, and decomposition

a. catabolic, exergonic, decomposition

what organic compound do brain cells primarily rely on for fuel a. glucose b. glycogen c. galactose d. glyceerol

a. glucose

number of protons in the nucleus of an atom

atomic number

the smallest unit of an element that maintains the properties of that element a. electron b. atom c. elemental particle d. isotope

b. atom

Ty is three years old and as a result of a "stomach bug" has been vomiting for about 24 hours. His blood pH is 7.48. What does this mean? a. blood is slightly acidic b. blood is slightly alkaline c. highly acidic d. blood is within the normal range

b. blood is slightly alkaline

substance composed of two or more different elements joined by chemical bonds

compound

describes a position above or higher than another part of the body proper; also referred to as superior

cranial

division of the posterior (dorsal) cavity that houses the brain

cranial cavity

describes a position farther from the surface of the body

deep

describes a position farther from the point of attachment or the trunk of the body

distal

posterior body cavity that houses the brain and spinal cord; also referred to as the posterior body cavity

dorsal cavity

subatomic particle having a negative charge and nearly no mass; found orbiting the atom's nucleus

electron

area of space a given distance from an atom's nucleus in which electrons are grouped

electron shell

substance that cannot be created or broken down by ordinary chemical means

element

two-dimensional, vertical plane that divides the body or organ into anterior and posterior portions

frontal plane

What organic compound do brain cells primarily rely on for fuel?

glucose

Ty is three years old and as a result of a "stomach bug" has been vomiting for about 24 hours. His blood pH is 7.48. What does this mean?

his blood is slightly alkaline

Which of the following combinations of atoms is most likely to result in a chemical reaction? -helium and helium -hydrogen and helium -neon and helium -hydrogen and hydrogen

hydrogen and hydrogen

one of the variations of an element in which the number of neutrons differ from each other

isotope

describes the side or direction toward the side of the body

lateral

sum of the amount of protons and neutrons in the nucleus of an atom

mass number

physical substance that which which occupies space and has mass

matter

describes the middle or direction toward the middle of the body

medial

heavy subatomic particle having no electrical charge and found in the atom's nucleus

neutron

A pentose sugar is a part of the monomer used to build which type of macromolecule?

nucleic acids

CH4 is methane. This compound is ________.

organic

sac that encloses the heart

pericardium

serous membrane that lines the abdominopelvic cavity and covers the organs found there

peritoneum

imaginary two-dimensional surface that passes through the body

plane

serous membrane that lines the pleural cavity and covers the lungs

pleura

describes the back or direction toward the back of the body; also referred to as the dorsal

posterior

posterior body cavity that houses the brain and spinal cord; also referred to as the dorsal cavity

posterior cavity

face down

prone

heavy subatomic particle having a positive charge and found in the atom's nucleus

proton

describes a position nearer to the point of attatchment or the trunk of the body

proximal

unstable, heavy isotope that gives off subatomic particles, or electromagnetic energy as it decays; also called radioisotopes

radioactive isotopes

two-dimensional, vertical plane that divides the body or organ into right and left sides

sagittal plane

in anatomy, a single flat surface of a three dimensional structure that has been cut through

section

membrane that covers organs and reduces friction; also referred to as serosa

serous membrane

The ability of an enzyme's active sites to bind only substrates of compatible shape and charge is known as ________.

specificity

division of the dorsal cavity that houses the spinal cord; also referred to as vertebral cavity

spinal cavity

describes a position nearer to the surface of the body

superficial

describes a position above or higher than another part of the body proper; also referred to as cranial

superior

face up

supine

Jenny mixes up a batch of pancake batter, then stirs in some chocolate chips. As she is waiting for the first few pancakes to cook, she notices the chocolate chips sinking to the bottom of the clear glass mixing bowl. The chocolate-chip batter is an example of a

suspension

divison of the anterior (ventral) cavity that houses the heart, lungs, esophagus, and trachea

thoracic cavity

two-dimensional, horizontal plane that divides the body or organ into superior and inferior portions

transverse plane

outermost electron shell of an atom

valence shell

describes the front or direction toward the front of the body; also referred to as anterior

ventral

larger body cavity located anterior to the posterior (dorsal) body cavity; includes the serous membrane-lined pleural cavities for the lungs, pericardial cavity for the heart, and peritoneal cavity for the abdominal and pelvic organs; also referred to as anterior body cavity

ventral cavity

What regulatory processes would your body use if you were trapped by a blizzard in an unheated, uninsulated cabin in the woods?

Any prolonged exposure to extreme cold would activate the brain's heat-gain center. This would reduce blood flow to your skin, and shunt blood returning from your limbs away from the digits and into a network of deep veins. Your brain's heat-gain center would also increase your muscle contraction, causing you to shiver. This increases the energy consumption of skeletal muscle and generates more heat. Your body would also produce thyroid hormone and epinephrine, chemicals that promote increased metabolism and heat production.

When you open a bottle of sparkling water, the carbon dioxide gas in the bottle form bubbles. If the bottle is left open, the water will eventually "go flat." Explain these phenomena in terms of atmospheric pressure.

In a sealed bottle of sparkling water, carbon dioxide gas is kept dissolved in the water under a very high pressure. When you open the bottle, the pressure of the gas above the liquid changes from artificially high to normal atmospheric pressure. The dissolved carbon dioxide gas expands, and rises in bubbles to the surface. When a bottle of sparkling water is left open, it eventually goes flat because its gases continue to move out of solution until the pressure in the water is approximately equal to atmospheric pressure.

The pH of lemon juice is 2, and the pH of orange juice is 4. Which of these is more acidic, and by how much? What does this mean?

Lemon juice is one hundred times more acidic than orange juice. This means that lemon juice has a one hundred-fold greater concentration of hydrogen ions.

Why is receptor-mediated endocytosis said to be more selective than phagocytosis or pinocytosis?

Receptor-mediated endocytosis is more selective because the substances that are brought into the cell are the specific ligands that could bind to the receptors being endocytosed. Phagocytosis or pinocytosis, on the other hand, have no such receptor-ligand specificity, and bring in whatever materials happen to be close to the membrane when it is enveloped.

Explain why the structure of the ER, mitochondria, and Golgi apparatus assist their respective functions.

The structure of the Golgi apparatus is suited to its function because it is a series of flattened membranous discs; substances are modified and packaged in sequential steps as they travel from one disc to the next. The structure of Golgi apparatus also involves a receiving face and a sending face, which organize cellular products as they enter and leave the Golgi apparatus. The ER and the mitochondria both have structural specializations that increase their surface area. In the mitochondria, the inner membrane is extensively folded, which increases surface area for ATP production. Likewise, the ER is elaborately wound throughout the cell, increasing its surface area for functions like lipid synthesis, Ca++ storage, and protein synthesis.

What do osmosis, diffusion, filtration, and the movement of ions away from like charge all have in common? In what way do they differ?

These four phenomena are similar in the sense that they describe the movement of substances down a particular type of gradient. Osmosis and diffusion involve the movement of water and other substances down their concentration gradients, respectively. Filtration describes the movement of particles down a pressure gradient, and the movement of ions away from like charge describes their movement down their electrical gradient.

which of the following statements about chemical bonds is true a. covalent bonds are stronger than ionic bonds b. hydrogen bonds occur between two atoms of hydrogen c. bonding readily occurs between nonpolar and polar molecules d. a molecule of water is unlikely to bond with an ion

a. covalent bonds are stronger than ionic bonds

which of the following combinations of atoms is most likely to result in a chemical reaction a. hydrogen and hydrogen b. hydrogen and helium c. helium and helium d. neon and helium

a. hydrogen and hydrogen

the energy stored in a foot of snow on a steep roof is a. potential energy b. kinetic energy c. radiant energy d. activation energy

a. potential energy

the characteristic that gives an element its distinctive properties is its number of a. protons b. neutrons c. electrons d. atoms

a. protons

which of the following is most likely to be found evenly distributed in water in a homogeneous solution a. sodium ions and chloride ions b. NaCl molecules c. salt crystals d. red blood cells

a. sodium ions and chloride ions

division of the anterior (ventral) cavity that houses the abdominal and pelvic viscera

abdominopelvic cavity

What separates the base pair at the start of DNA replication?

an enzyme

standard reference position used for describing locations and directions on the human body

anatomical position

describes the front or direction toward the front of the body; also referred to as ventral

anterior

cavity; includes the serous membrane-filled pleural cavities for the lungs, pericardial cavity for the heart, and peritoneal cavity for the abdominal and pelvic organs; also referred to as ventral cavity

anterior cavity

CH4 is methane. This compound is ________. a. inorganic b. organic c. reactive d. a crystal

b. organic

a substance formed of crystals of equal numbers of cations and anions held together by ionic bonds is called a(n) a. noble gas b. salt c. electrolyte d. dipole

b. salt

The bonding of calcium, phosphorus, and other elements produces mineral crystals that are found in bone. This is an example of a(n) ________ reaction. a. catabolic b. synthesis c. decomposition d. exchange

b. synthesis

Nitrogen has an atomic number of seven. How many electron shells does it likely have? a. one b. two c. three d. four

b. two

which of the following is a molecule, but not a compound a. H2O b. 2H c. H2 d. H+

c. H2

which of the following is a functional group that is part of a building block of protein a. phosphate b. adenine c. amino d. ribose

c. amino

AB--->A+B is a general notation for a ____ reaction a. anabolic b. endergonic c. decomposition d. exchange

c. decomposition

C6H12O6 is the chemical formula for a ________. a. polymer of carbohydrate b. pentose monosaccharide c. hexose monosaccharide d. all of the above

c. hexose monosaccharide

on the periodic table of the elements, mercury (Hg) has an atomic number of 80 and a mass number of 200.59. It has seven stable isotopes. The most abundant of these probably have a. about 80 neutrons each b. fewer than 80 neutrons each c. more than 80 neutrons each d. more electrons than neutrons

c. more than 80 neutrons each

a molecule of ammonia contains one atom of nitrogen and three atoms of hydrogen. These are linked with a. ionic bonds b. nonpolar covalent bonds c. polar covalent bonds d. hydrogen bonds

c. polar covalent bond

a substance dissociates into K+ and Cl- in solution. This substance is an a. acid b. base c. salt d. buffer

c. salt

describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column) also referred to as inferior

caudal

Together, just four elements make up more than 95 percent of the body's mass. These include ________. a. calcium, magnesium, iron, carbon b. oxygen, calcium, iron, nitrogen c. sodium, chlorine, carbon, hydrogen d. oxygen, carbon, hydrogen, nitrogen

d. oxygen, carbon, hydrogen, nitrogen

Chewing a bite of bread mixes it with saliva and facilitates its chemical breakdown. This is most likely due to the fact that ________. a. the inside of the mouth maintains a very high temperature b. chewing stores potential energy c. chewing facilitates synthesis reactions d. saliva contains enzymes

d. saliva contains enzymes

Jenny mixes up a batch of pancake batter, then stirs in some chocolate chips. As she is waiting for the first few pancakes to cook, she notices the chocolate chips sinking to the bottom of the clear glass mixing bowl. The chocolate chip batter is an example of a ________. a. solvent b. solute c. solution d. suspension

d. suspension

describes the back or direction toward the back of the body; also referred to as posterior

dorsal