A&p 1 Final
A&p 1 final
- 1.
The primary role of the biological pigment melanin is
- A.
Cutaneous stretch sensation
- B.
Protect DNA from UV damage
- C.
Activate immune cells in response to microorganisms
- D.
Aid in tissue repair after mechanical stress/ damage
- E.
None of the above
Correct Answer
B. Protect DNA from UV damageExplanation
Melanin is a biological pigment found in the skin, hair, and eyes. Its primary role is to protect DNA from UV damage. Melanin acts as a natural sunscreen by absorbing and dispersing UV radiation, preventing it from causing damage to the DNA in skin cells. This protection is crucial as UV radiation can lead to DNA mutations and potentially increase the risk of skin cancer. Therefore, melanin plays a vital role in safeguarding the genetic material within our cells from harmful UV rays.Rate this question:
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- 2.
____________ muscle tissue is striated, branched and has intercalated disks
- A.
Skeletal
- B.
Voluntary
- C.
Involuntary
- D.
Cardiac
- E.
Smooth
Correct Answer
D. CardiacExplanation
Cardiac muscle tissue is striated, branched, and has intercalated disks. Unlike skeletal muscle, which is also striated but is voluntary, cardiac muscle is involuntary, meaning it contracts without conscious control. The presence of intercalated disks allows for synchronized contractions of cardiac muscle cells, ensuring efficient pumping of blood. This unique structure and function make cardiac muscle tissue well-suited for its role in the heart, where it contracts rhythmically to circulate blood throughout the body.Rate this question:
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- 3.
____________ adhere neighboring cells together so that no fluids or solutes may pass between the cells
- A.
Tight junctions
- B.
Connexons
- C.
Keratin
- D.
Desmosomes
- E.
Gap junctions
Correct Answer
A. Tight junctionsExplanation
Tight junctions are specialized protein structures that tightly adhere neighboring cells together, forming a barrier that prevents the passage of fluids or solutes between the cells. This helps to maintain the integrity and function of tissues by preventing the leakage of substances between cells. Tight junctions are commonly found in epithelial tissues, such as the lining of the digestive tract, where they play a crucial role in regulating the movement of molecules across the tissue.Rate this question:
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- 4.
___________ epithelium appears to have two or three layers of cells, but all the cells are in contact with the basement membrane
- A.
Simple squamous
- B.
Complex
- C.
Stratified
- D.
Cuboidal
- E.
Pseudostratified
Correct Answer
E. PseudostratifiedExplanation
Pseudostratified epithelium appears to have two or three layers of cells because the nuclei of the cells are at different levels, giving the appearance of stratification. However, all the cells are in contact with the basement membrane, which distinguishes it from true stratified epithelium. Therefore, the correct answer is pseudostratified.Rate this question:
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- 5.
__________consists of a layer of spongy bone sandwhiched between two layers of compact bone
- A.
Periosteum
- B.
Flat bone
- C.
Diaphysis
- D.
Interstitial lamellae
- E.
Hyaline cartilage
Correct Answer
D. Interstitial lamellaeExplanation
The interstitial lamellae consist of a layer of spongy bone sandwiched between two layers of compact bone. These lamellae are found in the osteons, which are the structural units of compact bone. They fill the spaces between the osteons and help to strengthen the bone tissue. The periosteum is a fibrous membrane that covers the outer surface of bones. Flat bones are thin and flat, such as the bones of the skull. The diaphysis is the shaft of a long bone. Hyaline cartilage is a type of cartilage that covers the ends of bones in joints.Rate this question:
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- 6.
Wolfs law is concerned with ______________
- A.
Calcium homeostasis
- B.
The thickness and strength of bone being determined by mechanical and gravitational forces
- C.
The electrical charge in the bone surface
- D.
The rate of bone repair following a fracture
- E.
The strength to weight ratio of bone tissue determined by the relative composition of organic and inorganic components
Correct Answer
B. The thickness and strength of bone being determined by mechanical and gravitational forcesExplanation
Wolff's law states that bone in a healthy person will adapt to the loads under which it is placed. This means that the thickness and strength of bone are determined by mechanical and gravitational forces. As the bone is subjected to these forces, it remodels itself to become stronger and more resistant to those forces. This principle is important in understanding how bones respond to physical activity and why they may become weaker or stronger depending on the level of mechanical stress they experience.Rate this question:
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- 7.
Which type of muscle tissue would be found in the walls of arteries?
- A.
Striated muscle
- B.
Skeletal muscle
- C.
Caridac muscle
- D.
Smooth muscle
- E.
None of the above
Correct Answer
D. Smooth muscleExplanation
Smooth muscle would be found in the walls of arteries. Smooth muscle is a type of muscle tissue that is involuntary and non-striated. It is responsible for the contraction and relaxation of the walls of various organs and blood vessels, including arteries. This type of muscle tissue allows for the regulation of blood flow and helps to maintain blood pressure.Rate this question:
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- 8.
Which structure of the integumentary system would most likely respond to a sudden drop in temperature?
- A.
Eccrine glands
- B.
Arrector pili
- C.
Ceruminous glands
- D.
Pacinian corpuscle
- E.
Merkel disk
Correct Answer
B. Arrector piliExplanation
The arrector pili muscles are responsible for causing goosebumps on the skin. When the body experiences a sudden drop in temperature, these muscles contract, causing the hair follicles to stand up. This response is a way for the body to trap a layer of air around the skin, which helps to insulate and warm the body. Therefore, the arrector pili muscles would most likely respond to a sudden drop in temperature.Rate this question:
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- 9.
Which statement best describes connective tissue?
- A.
Usually contains large amounts of extracellular matrix
- B.
Primary concerned with secretion
- C.
Usually lines a body cavity or covers an organ
- D.
Typically arranged in a single cell layer
- E.
Mostly functions to signal information to other tissues
Correct Answer
A. Usually contains large amounts of extracellular matrixExplanation
Connective tissue is best described as usually containing large amounts of extracellular matrix. This matrix consists of various proteins and fibers that provide support, strength, and flexibility to the tissue. Connective tissue also contains cells, such as fibroblasts, adipocytes, and immune cells, which are responsible for maintaining and repairing the tissue. The extracellular matrix plays a crucial role in connecting and supporting different structures in the body, such as bones, tendons, and blood vessels.Rate this question:
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- 10.
Which of these nonmetals is not listed with the number of covalent bonds it naturally forms?
- A.
O oxygen 2
- B.
C carbon 3
- C.
N nitrogen 3
- D.
H hydrogen 1
- E.
Na sodium 2
Correct Answer
B. C carbon 3Explanation
Carbon is not listed with the number of covalent bonds it naturally forms. This means that the number of covalent bonds formed by carbon is not mentioned in the given options.Rate this question:
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- 11.
Which of the following systems is dependent on the cardiovascular system for its function?
- A.
Digestive system
- B.
Nervous system
- C.
Skeletal system
- D.
Integumentary system
- E.
All of the above
Correct Answer
E. All of the aboveExplanation
All of the above systems are dependent on the cardiovascular system for their function. The cardiovascular system, which includes the heart and blood vessels, is responsible for transporting oxygen, nutrients, hormones, and waste products throughout the body. The digestive system relies on the cardiovascular system to deliver nutrients and remove waste products. The nervous system requires a constant supply of oxygen and glucose, which are delivered by the cardiovascular system. The skeletal system relies on the cardiovascular system to deliver calcium and other nutrients for bone growth and repair. The integumentary system, which includes the skin, relies on the cardiovascular system to regulate body temperature and deliver nutrients to skin cells.Rate this question:
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- 12.
Which of the following is true concerning the atomic nucleus?
- A.
Contains the mass of the atom
- B.
Contains the particle that create chemical bonds
- C.
Contains negatively charged particles
- D.
Its mass is constantly changing
- E.
None of the above
Correct Answer
A. Contains the mass of the atomExplanation
The atomic nucleus contains the mass of the atom because it is made up of protons and neutrons, which have a much greater mass compared to the electrons orbiting the nucleus. The mass of the electrons is negligible in comparison to the mass of the protons and neutrons. Therefore, the majority of the mass of an atom is concentrated in its nucleus.Rate this question:
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- 13.
Which of the following is not a functional charactersistic of life?
- A.
Movement
- B.
Responsiveness to external stimuli
- C.
Maintenance of external boundry
- D.
Decay
- E.
Reproduction
Correct Answer
D. DecayExplanation
Decay is not a functional characteristic of life because it refers to the breakdown or decomposition of organic matter, which is a process that occurs after an organism has died. While movement, responsiveness to external stimuli, maintenance of external boundary, and reproduction are all essential functional characteristics of living organisms, decay is not directly related to the processes that sustain life.Rate this question:
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- 14.
Which of the following is not a characteristic of epithelial tissue
- A.
Exhibits polarity
- B.
Supported by connective tissue
- C.
Highly vascualr (supplied with blood vessels)
- D.
Innervated (supplied by nerve fibers)
- E.
Highly regenerative
Correct Answer
C. Highly vascualr (supplied with blood vessels)Explanation
Epithelial tissue is a type of tissue that covers the surfaces of organs and lines the body cavities. It exhibits polarity, meaning it has distinct apical and basal surfaces. It is supported by connective tissue, which provides structural support. Epithelial tissue is highly regenerative, meaning it has the ability to repair and replace damaged cells. However, it is not highly vascular, meaning it is not supplied with a large number of blood vessels. This is because epithelial cells obtain nutrients and oxygen through diffusion from nearby blood vessels in the underlying connective tissue.Rate this question:
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- 15.
Which of the following is an example of a lipid?
- A.
Amino acid
- B.
Enzymes
- C.
Cholesterol
- D.
Glycogen
- E.
Tryptophan
Correct Answer
C. CholesterolExplanation
Cholesterol is a type of lipid, specifically a sterol. Lipids are a diverse group of molecules that includes fats, phospholipids, and sterols like cholesterol. Amino acids, enzymes, glycogen, and tryptophan are not lipids; amino acids are the building blocks of proteins, enzymes are proteins, glycogen is a carbohydrate, and tryptophan is an amino acid.Rate this question:
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- 16.
Which of the following is a principle of the fluid mosaic model of cell membrane structure?
- A.
The cell membrane is solid at room temperature thus protecting the cell
- B.
Membrane proteins "float" within the lipid bilayer creating a constantly changing mosaic pattern
- C.
Membrane proteins transport fluids from the interior to the exterior of the cell
- D.
The phospholipids that compose the membrane are tightly attached to each other to prevent fluid loss
- E.
None of the above
Correct Answer
B. Membrane proteins "float" within the lipid bilayer creating a constantly changing mosaic patternExplanation
The principle of the fluid mosaic model of cell membrane structure is that membrane proteins "float" within the lipid bilayer, creating a constantly changing mosaic pattern. This means that the proteins are not fixed in place but are able to move within the lipid bilayer, giving the membrane its fluidity. This allows for various functions such as transport, signaling, and cell recognition to occur efficiently.Rate this question:
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- 17.
Which of the following epdiermal glands produces a milky sweat that tends to become odoriferous over time?
- A.
Sebaceous
- B.
Eccrine
- C.
Merkel
- D.
Aprocrine
- E.
Axillary
Correct Answer
D. AprocrineExplanation
Apocrine glands are a type of epidermal gland that produce a milky sweat. This sweat contains proteins and lipids that are odorless when first secreted, but can become odoriferous over time due to the action of bacteria on the sweat. These glands are found in areas such as the armpits and groin, and their secretion is influenced by hormonal changes and emotional stress. Sebaceous glands, on the other hand, produce sebum, which is an oily substance that helps lubricate the skin and hair. Eccrine glands produce a clear, watery sweat that helps regulate body temperature. Merkel cells are not glands, but rather sensory receptors involved in touch sensation. Axillary refers to the armpit area.Rate this question:
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- 18.
Which of the following elements is most likely to form an ionic bond with potassium (atomic symbol K)?
- A.
Carbon
- B.
Oxygen
- C.
Sodium
- D.
Chlorine
- E.
Nitrogen
Correct Answer
D. ChlorineExplanation
Chlorine is most likely to form an ionic bond with potassium because chlorine is a halogen and has a strong tendency to gain one electron to achieve a stable electron configuration. On the other hand, potassium has one electron in its outermost shell and tends to lose that electron to achieve a stable configuration. Therefore, chlorine and potassium have opposite charges and can easily form an ionic bond.Rate this question:
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- 19.
Which is not essential for survival
- A.
Water
- B.
Oxygen
- C.
Nutrients
- D.
Light
- E.
None of the above
Correct Answer
D. LightExplanation
Light is not essential for survival because it is not a basic requirement for sustaining life. While water, oxygen, and nutrients are necessary for various physiological processes in the body, light is not directly involved in sustaining life. Although light is important for photosynthesis in plants and plays a role in regulating the circadian rhythm in some organisms, it is not essential for survival in the same way that water, oxygen, and nutrients are.Rate this question:
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- 20.
Which element is matched with the correct number of valence electrons
- A.
Carbon, 5
- B.
Sodium, 1
- C.
Oxygen, 3
- D.
Nitrogen, 2
- E.
Chlorine, 6
Correct Answer
B. Sodium, 1Explanation
Sodium is matched with the correct number of valence electrons, which is 1. Valence electrons are the electrons located in the outermost energy level of an atom and are involved in chemical bonding. Sodium belongs to group 1 of the periodic table, which means it has 1 valence electron. This electron is easily lost during chemical reactions, making sodium highly reactive and likely to form positive ions.Rate this question:
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- 21.
What chemical is stored in the synaptic vesicles of a motor neuron?
- A.
potassium
- B.
Sodium
- C.
ATP
- D.
Calcium
- E.
Acetylcholine
Correct Answer
E. AcetylcholineExplanation
Acetylcholine is the correct answer because it is a chemical neurotransmitter that is stored in the synaptic vesicles of a motor neuron. When an action potential reaches the end of a motor neuron, acetylcholine is released into the synaptic cleft, where it binds to receptors on the muscle cell, causing muscle contraction. This process is essential for the transmission of signals from the motor neuron to the muscle, allowing for voluntary movement.Rate this question:
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- 22.
What is the direct role of ATP hydrolysis in skeletal muscle contraction?
- A.
Promotes a shift of tropomyosin, exposing myosin binding sites on actin
- B.
Opens calcium channels in the sarcoplasmic reticulum
- C.
Return the myosin head to the high energy "cocked" position
- D.
Allows the myosin to form crossbridges with the actin filament
- E.
None of the above
Correct Answer
C. Return the myosin head to the high energy "cocked" positionExplanation
ATP hydrolysis provides the energy required to detach the myosin head from the actin filament during muscle contraction. This allows the myosin head to return to its high energy "cocked" position, ready to form new crossbridges with the actin filament. Therefore, the correct answer is that ATP hydrolysis returns the myosin head to the high energy "cocked" position.Rate this question:
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- 23.
What is aponeurosis?
- A.
A sheetlike extension of connective tissue that provides indirect attachment for muscles to bone
- B.
A whispy sheath of connective tissue that suround each individual muscle fiber
- C.
An "overcoat" of dense irregular connective tissue that surrounds the whole muscle
- D.
Granule of stored glycogen that provides glucose during muscle activity
- E.
A rodlike bundle of contractile filaments
Correct Answer
A. A sheetlike extension of connective tissue that provides indirect attachment for muscles to boneExplanation
Aponeurosis is a sheetlike extension of connective tissue that provides indirect attachment for muscles to bone. It acts as a strong, flat tendon that connects muscles to bones or other muscles. This structure helps distribute the force generated by muscle contraction over a larger area, allowing for more efficient movement and reducing the risk of injury.Rate this question:
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- 24.
What is acetylchoinesterase?
- A.
An enzyme that breaks down acetylcholine
- B.
Signaling molecule that initiates contraction
- C.
Protein that blocks the myosin binding site on actin filaments
- D.
The control center for excitation contraction coupling
- E.
None of the above
Correct Answer
A. An enzyme that breaks down acetylcholineExplanation
Acetylcholinesterase is an enzyme that breaks down acetylcholine. Acetylcholine is a neurotransmitter that is involved in the transmission of signals between nerve cells. Acetylcholinesterase plays a crucial role in regulating the levels of acetylcholine in the synaptic cleft, where it breaks down acetylcholine into choline and acetate. This breakdown process is essential for terminating the signal transmission and allowing the nerve cells to reset and prepare for the next signal. Therefore, the correct answer is that acetylcholinesterase is an enzyme that breaks down acetylcholine.Rate this question:
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- 25.
Virtually all chemical reactions in our body are catalized (sped up) by
- A.
Salts
- B.
Enzymes
- C.
Phospholipids
- D.
Polysaccharides
- E.
Electrolytes
Correct Answer
B. EnzymesExplanation
Enzymes are proteins that act as catalysts in the body, meaning they speed up chemical reactions without being consumed in the process. They play a crucial role in various biological processes such as digestion, metabolism, and DNA replication. Unlike other options like salts, phospholipids, polysaccharides, and electrolytes, enzymes have specific structures that allow them to bind to substrates and facilitate reactions. Therefore, enzymes are the most appropriate answer as they are specifically designed to catalyze chemical reactions in the body.Rate this question:
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- 26.
The________joint is an example of a ball and socket joint
- A.
Shoulder
- B.
Wrist
- C.
Elbow
- D.
Temporomandibular
- E.
None of the above
Correct Answer
A. ShoulderExplanation
The shoulder joint is an example of a ball and socket joint because it consists of the rounded head of the humerus bone fitting into the shallow socket of the scapula bone. This allows for a wide range of motion in multiple directions, similar to how a ball can move freely in a socket. The wrist, elbow, and temporomandibular joints do not have the same structure as a ball and socket joint, making the shoulder the correct answer.Rate this question:
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- 27.
These cells primarily function as part of the integuments role as a biological barrier
- A.
Langerhans (dendritic) cells
- B.
Melanocytes
- C.
Merkel
- D.
Arrector pili
- E.
Alpha cells
Correct Answer
A. Langerhans (dendritic) cellsExplanation
Langerhans (dendritic) cells are a type of immune cell found in the skin's outermost layer, known as the epidermis. These cells play a crucial role in the integumentary system's function as a biological barrier. They are responsible for detecting and capturing foreign substances, such as pathogens, in the skin. Langerhans cells then present these substances to other immune cells, initiating an immune response to protect the body from potential harm. Therefore, their primary function aligns with the integument's role as a biological barrier.Rate this question:
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- 28.
The __________ system eliminates nitrogenous waste and regulates water and electrolyte balance
- A.
Digestive
- B.
Excretory
- C.
Respiratory
- D.
Cardiovascular
- E.
Endocrine
Correct Answer
B. ExcretoryExplanation
The excretory system is responsible for eliminating nitrogenous waste, such as urea, from the body. It also plays a crucial role in regulating water and electrolyte balance by controlling the amount of water and ions that are excreted in urine. The digestive system is primarily responsible for breaking down food and absorbing nutrients, while the respiratory system is involved in gas exchange. The cardiovascular system transports oxygen, nutrients, and waste products throughout the body. The endocrine system regulates various bodily functions through the release of hormones. Therefore, the excretory system is the correct answer as it specifically deals with waste elimination and water-electrolyte balance.Rate this question:
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- 29.
The ________ give an osteon a structure resembling tree rings
- A.
Canaliculi
- B.
Lamellae
- C.
Central canal
- D.
Trabeculae
- E.
Volkmanns canal
Correct Answer
B. LamellaeExplanation
Lamellae are concentric rings of bone matrix that surround the central canal in an osteon. These rings give the osteon a structure resembling tree rings.Rate this question:
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- 30.
The _______ bone is an example of a facial bone
- A.
Zygomatic
- B.
Parietal
- C.
Lamboid
- D.
Temporal
- E.
Occipital
Correct Answer
A. ZygomaticExplanation
The zygomatic bone is considered a facial bone because it is located in the face. It is commonly known as the cheekbone and forms the prominence of the cheek. This bone connects with other facial bones such as the maxilla, frontal bone, and temporal bone to form the structure of the face. It also plays a role in protecting the eye and supporting the muscles involved in facial expression.Rate this question:
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- 31.
The two layers of an articular capsule of a synovial joint are ______ and________.
- A.
Intervening pad, periosteum
- B.
Fibrous capsule, synovial membrane
- C.
Synovial membrane, bursa
- D.
Fibrous capsule, fatty pad
- E.
None of the above
Correct Answer
B. Fibrous capsule, synovial membraneExplanation
The two layers of an articular capsule of a synovial joint are the fibrous capsule and the synovial membrane. The fibrous capsule provides stability and strength to the joint, while the synovial membrane produces synovial fluid, which lubricates the joint and reduces friction.Rate this question:
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- 32.
The three primary element of the cytoskeleton are microfilaments, intermediate filaments and
- A.
Centrioles
- B.
Nuclear pores
- C.
Microtubules
- D.
Connexons
- E.
Fibrocytes
Correct Answer
C. MicrotubulesExplanation
Microtubules are one of the three primary elements of the cytoskeleton. They are long, hollow tubes made up of protein called tubulin. They provide structural support to the cell and are involved in various cellular processes such as cell division, intracellular transport, and maintenance of cell shape. Microtubules also serve as tracks along which organelles and vesicles move within the cell. Therefore, microtubules play a crucial role in maintaining the shape and structure of the cell, as well as facilitating cellular functions.Rate this question:
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- 33.
The subatomic particle that determines what the specific element is:
- A.
Electron
- B.
Proton
- C.
Isotope
- D.
Neutron
- E.
Lepton
Correct Answer
B. ProtonExplanation
The proton is the subatomic particle that determines what the specific element is. Protons carry a positive charge and are found in the nucleus of an atom. The number of protons in an atom is what defines its atomic number and determines the element it belongs to. For example, an atom with one proton is hydrogen, while an atom with six protons is carbon. Therefore, the presence and number of protons in an atom are crucial in identifying and classifying elements.Rate this question:
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- 34.
The structure in compact bone that runs perpendicular (right angle) to connect adjacent osteons is called ___________.
- A.
Volkmann's canal
- B.
Circumferential lamellae
- C.
Haversian canal
- D.
Lacunae
- E.
Trabeculae
Correct Answer
A. Volkmann's canalExplanation
Volkmann's canals are the structures in compact bone that run perpendicular to connect adjacent osteons. These canals allow for the passage of blood vessels, nerves, and connective tissue, facilitating communication and nutrient exchange between osteons. The other options, such as circumferential lamellae, haversian canal, lacunae, and trabeculae, are all important components of bone structure but do not specifically describe the structure that connects adjacent osteons in compact bone.Rate this question:
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- 35.
The stratum lucidum is found
- A.
Just deep to the papillary layer
- B.
Within the areolar tissure of the dermal layer
- C.
Only in thick skin
- D.
More in females than males
- E.
All of the above
Correct Answer
C. Only in thick skinExplanation
The stratum lucidum is a layer of the epidermis that is only found in thick skin. Thick skin is typically found on the palms of the hands and soles of the feet, where there is increased friction and pressure. This layer is not present in thin skin, which is found in other areas of the body. Therefore, the correct answer is "only in thick skin".Rate this question:
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- 36.
The stratum basale of the epidermis can best be described as
- A.
Playing a major role in water proofing the skin
- B.
Simple epithelium with an excretory function
- C.
Primarily immune system cells
- D.
Storage cell for subcutaneous fat
- E.
Single layer of mitotically active cells
Correct Answer
E. Single layer of mitotically active cellsExplanation
The stratum basale of the epidermis is the innermost layer and is responsible for continuous cell division. It consists of a single layer of cells that are actively dividing through mitosis. These cells then move up to the upper layers of the epidermis, undergoing differentiation and eventually forming the outermost layer of the skin. This constant cell division and renewal in the stratum basale helps in the growth and repair of the epidermis, making it the correct answer.Rate this question:
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- 37.
The sodium/potassium pump is an example of
- A.
Simple diffusion
- B.
Facilitated diffusion
- C.
Osmosis
- D.
Active transport
- E.
Receptor mediated endocytosis
Correct Answer
D. Active transportExplanation
The sodium/potassium pump is an example of active transport because it actively moves sodium and potassium ions against their concentration gradients, requiring the expenditure of energy in the form of ATP. Unlike simple diffusion or facilitated diffusion, which occur down the concentration gradient and do not require energy, active transport moves substances against the concentration gradient, from low to high concentration, and therefore requires energy. Osmosis is the movement of water molecules across a selectively permeable membrane, and receptor-mediated endocytosis is the process by which cells take in specific molecules through receptor binding and internalization, neither of which are applicable to the sodium/potassium pump.Rate this question:
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- 38.
The sliding filament model of contraction involves
- A.
Actin and myosin filaments sliding past each other while partially overlapping
- B.
The shortening of thick filaments so that each thin filament slides past it
- C.
Actin being broken down during each contraction and replaced while resting
- D.
Actin heads binding to ATP and sliding the myosin filaments inward
- E.
Actin and myosin filaments getting shorter, but not sliding past each other
Correct Answer
A. Actin and myosin filaments sliding past each other while partially overlappingExplanation
The sliding filament model of contraction explains how actin and myosin filaments interact during muscle contraction. According to this model, the actin and myosin filaments slide past each other while partially overlapping. This sliding motion is facilitated by the binding of actin heads to ATP and the inward sliding of the myosin filaments. As a result of this sliding, the muscle fibers contract and generate force. This explanation aligns with the concept of the sliding filament model and accurately describes the process of muscle contraction.Rate this question:
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- 39.
The sarcoplasmic reticulum stores what cation?
- A.
Potassium
- B.
Sodium
- C.
Phosphate
- D.
Calcium
- E.
Magnesium
Correct Answer
D. CalciumExplanation
The sarcoplasmic reticulum is a specialized organelle found in muscle cells that is responsible for storing and releasing calcium ions. Calcium ions play a crucial role in muscle contraction, as they bind to proteins within the muscle fibers, allowing them to interact and generate force. Therefore, the correct answer is calcium.Rate this question:
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- 40.
The role of cholestrol in the plasma membrane is to
- A.
Prevent excess sodium from entering the cell
- B.
Act as an "identifacation tag" for neighboring cells
- C.
Import glucose molecules
- D.
Stabalize and increase the fluidty of the membrane
- E.
Increase surface area to aid absorption
Correct Answer
D. Stabalize and increase the fluidty of the membraneExplanation
Cholesterol plays a crucial role in stabilizing and increasing the fluidity of the plasma membrane. It helps to maintain the integrity and structure of the membrane by preventing it from becoming too rigid or too fluid. Cholesterol molecules are interspersed between the phospholipids in the membrane, reducing their ability to pack tightly together and thus making the membrane more fluid. This fluidity is essential for various cellular processes such as cell signaling, membrane transport, and protein function.Rate this question:
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- 41.
The rib cage contains ____true ribs,_____ false ribs, and ______ floating ribs
- A.
7, 3, 2
- B.
8, 2, 3
- C.
6, 4, 3
- D.
10, 1, 2
- E.
9, 4, 4
Correct Answer
A. 7, 3, 2Explanation
The rib cage contains 7 true ribs, 3 false ribs, and 2 floating ribs. The true ribs are directly attached to the sternum, while the false ribs are connected to the sternum indirectly through cartilage. The floating ribs are not attached to the sternum at all.Rate this question:
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- 42.
The region of the sarcolemma that carries an action potential into the deep interior of a muscle is called a
- A.
Neuromuscular junction
- B.
Myofibril
- C.
T- tubule
- D.
Aponeurosis
- E.
Motor end plate
Correct Answer
C. T- tubuleExplanation
The t-tubule is a region of the sarcolemma that carries an action potential into the deep interior of a muscle. This allows for the efficient transmission of the electrical signal throughout the muscle fiber, leading to muscle contraction. The t-tubules are invaginations of the sarcolemma that penetrate deep into the muscle fiber, allowing for the rapid spread of the action potential and ensuring synchronized contraction of the entire muscle.Rate this question:
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- 43.
The region of the sarcolemma that carries an action potential into the deep interior of a muscle is called a
- A.
Neuromuscular junction
- B.
Terminal cisterna
- C.
T-tubule
- D.
Aponeruosis
- E.
Motor end plate
Correct Answer
C. T-tubuleExplanation
The t-tubule is a region of the sarcolemma that carries an action potential into the deep interior of a muscle. It is responsible for transmitting the electrical signal rapidly and efficiently throughout the muscle fiber, allowing for synchronized contraction. The t-tubule system is closely associated with the sarcoplasmic reticulum, which releases calcium ions to initiate muscle contraction.Rate this question:
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- 44.
The process of bone remodling called bone resorption is accomplished by _________ in response to_________ Ca2+ levels in the blood
- A.
Osteoblasts, low
- B.
Osteoclasts, high
- C.
Osteoblasts, high
- D.
Osteoclasts, excessive
- E.
Osteoclasts, low
Correct Answer
E. Osteoclasts, lowExplanation
Bone resorption is the process of breaking down and removing old or damaged bone tissue. This process is accomplished by osteoclasts, which are specialized cells that break down bone. The question states that bone resorption occurs in response to low Ca2+ levels in the blood. When blood Ca2+ levels are low, the body needs to release calcium from the bones to maintain a proper balance. Osteoclasts are responsible for breaking down the bone tissue to release calcium into the bloodstream. Therefore, the correct answer is osteoclasts, low.Rate this question:
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- 45.
The principle that states that the structure and function of any bodily system are inseparable is known as the principle of
- A.
Symbiosis
- B.
Duality
- C.
Continuity
- D.
Sustainability
- E.
Complementarity
Correct Answer
E. ComplementarityExplanation
The principle of complementarity states that the structure and function of any bodily system are inseparable. This means that the way a system is structured determines its function, and the function of a system is dependent on its structure. In other words, the form and function of a bodily system are interrelated and cannot be separated. This principle is fundamental in understanding how different components of the body work together to maintain overall health and well-being.Rate this question:
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- 46.
The primary role of nervous tissue is to ______________
- A.
Respond to stimuli and transmit electrical signals to other body regions
- B.
Pull on the skin and bones to create body movements
- C.
Provide cushioning and protection for vital organs
- D.
Function as a barrier
Correct Answer
A. Respond to stimuli and transmit electrical signals to other body regionsExplanation
Nervous tissue is responsible for responding to stimuli and transmitting electrical signals to other body regions. This is achieved through the specialized cells called neurons, which can detect changes in the internal or external environment and generate electrical impulses. These impulses are then transmitted through the nervous system, allowing for communication between different parts of the body and enabling the coordination of various physiological processes and behaviors.Rate this question:
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- 47.
The primary protein constituent of thick myofilaments is
- A.
Tropomyosin
- B.
Myosin
- C.
Actin
- D.
Troponin
- E.
Tubulin
Correct Answer
B. MyosinExplanation
Myosin is the correct answer because it is the primary protein constituent of thick myofilaments. Thick myofilaments are responsible for generating the force during muscle contraction, and myosin is the main component of these filaments. Myosin molecules have a long tail and a globular head that interacts with actin, another protein involved in muscle contraction. This interaction allows myosin to generate the sliding motion of the filaments, leading to muscle contraction. Therefore, myosin is the primary protein constituent of thick myofilaments.Rate this question:
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- 48.
The overall three-dimensional structure of one folded polypeptide (protein) is called its __________ structure.
- A.
Primary
- B.
Secondary
- C.
Tertiary
- D.
Quaternary
- E.
Double helix
Correct Answer
C. TertiaryExplanation
The overall three-dimensional structure of a protein is called its tertiary structure. This structure is formed by the folding of the polypeptide chain, resulting in a complex three-dimensional shape. The tertiary structure is crucial for the protein's function, as it determines how the protein interacts with other molecules and carries out its specific biological role. The primary structure refers to the linear sequence of amino acids, the secondary structure refers to local folding patterns such as alpha helices and beta sheets, and the quaternary structure refers to the arrangement of multiple polypeptide chains in a protein complex. "Double helix" is not a term used to describe the structure of proteins.Rate this question:
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- 49.
The occipital bone of the skull is an example of a (n)
- A.
Long bone
- B.
Short bone
- C.
Flat bone
- D.
Intermediate bone
- E.
Irregular bone
Correct Answer
C. Flat boneExplanation
The occipital bone of the skull is classified as a flat bone because it is thin, flat, and curved in shape. Flat bones are found in areas that require protection of underlying organs, such as the skull, sternum, and ribs. They provide a broad surface area for muscle attachment and serve as a protective barrier.Rate this question:
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- 50.
The movement of molecules or ions down their concentration gradient and across a biological membrane utilizing a transmembrane protein without the use of ATP is called
- A.
Simple diffusion
- B.
Facilitated diffusion
- C.
Active transport
- D.
Osmosis
- E.
Complex diffusion
Correct Answer
B. Facilitated diffusionExplanation
Facilitated diffusion is the correct answer because it refers to the movement of molecules or ions across a biological membrane with the help of transmembrane proteins, without the use of ATP. These proteins act as channels or carriers, allowing specific substances to pass through the membrane. Unlike active transport, facilitated diffusion does not require energy expenditure. Simple diffusion refers to the movement of substances directly through the lipid bilayer, while osmosis specifically refers to the movement of water molecules. Complex diffusion is not a recognized term in biology.Rate this question:
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Jun 14, 2023Quiz Edited by
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Dec 11, 2010Quiz Created by
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