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BIO 141 FINAL EXAM QUESTIONS WITH COMPLETE
SOLUTIONS
What type of bond is responsible for the surface tension of water? -- Answer โโ Hydrogen bond Resting membrane potential is due to unequal concentrations of: -- Answer โโ Ions What type of reaction is A+ B+ Energyโ AB -- Answer โโ Endergonic reaction Cells in the epidermis of the skin need to be held tightly together so that an impermeable barrier to fluids is created. What type of junction performs this function? -
- Answer โโ Tight junction Within the epiphyseal plate, which zone houses actively dividing cartilage cells in their lacunae? -- Answer โโ Zone of proliferation All cells in the epidermis arise from mitotic activity in stratum: -- Answer โโ Basale
A patient has skin that is slightly blue in color. A likely treatment for this person might be __________. -- Answer โโ Giving the patient supplemental oxygen by mask. Which of the following is NOT a characteristic of epithelial tissue? -- Answer โโ It contains abundant blood vessels. Which of the following is NOT a function of the skeletal system? -- Answer โโ Communication Hair production occurs at the hair: -- Answer โโ Matrix Mechanical stress of bones, such as that caused by weight lifting, is detected by: -- Answer โโ Osteocytes, which then communicate to osteoblasts to increase synthesis of osteoid. What general tissue type binds, supports, and protects the body? -- Answer โโ Connective Glands that secrete their products directly into the blood rather than through ducts are classified as ___________. -- Answer โโ Endocrine Rickets is a disease characterized by deficient calcification of osteoid tissue due to a vitamin deficiency. A lack of which vitamin could cause this disease? -- Answer โโ Vitamin D
The cell responsible for secreting the matrix of the bone is the ______________. -- Answer โโ Osteoblast What type of secretion involves the release of substances, such as saliva and sweat, in secretory vesicles by exocytosis? -- Answer โโ Merocrine Why is vitamin D necessary? -- Answer โโ Vitamin D is required for calcium absorption from the small intestine. Secondary ossification centers are characteristic of: -- Answer โโ Endochondral ossification What function do fibroblasts serve in connective tissue? -- Answer โโ Secrete proteins that become fibers in the connective tissue matrix. Which of the following does NOT correctly describe the effects of parathyroid hormone (PTH)? -- Answer โโ PTH decreases blood calcium ion concentration. In addition to protection (physical and chemical barrier), the skin serves other functions. Which of the following is another vital function of the skin? -- Answer โโ It converts modified epidermal cholesterol to a vitamin D precursor important to calcium metabolism. Correctly order the following key steps in the process of endochondral ossification.
- Chondrocytes die.
- Osteoblasts build the bone collar on the external surface of the bone.
- Perichondrium is invaded by blood vessels.
- In the primary ossification center, osteoblasts replace calcified cartilage with early spongy bone.
- Perichondrial cells differentiate into osteogenic cells then into osteoblasts. -- Answer โโ 3, 5, 2, 1, 4 Which of the following statements indicates the way in which the body's natural defenses protect the skin from the effects of UV damage? -- Answer โโ Prolonged exposure to the sun increases melanin production, which in turn acts as a natural sunscreen. A needle would pierce the epidermal layers of the forearm in which order? -- Answer โโ Corneum, granulosum, spinosum, basale What type of bone growth do you think a 40-year-old male experiences? -- Answer โโ Appositional growth Synovial membranes: -- Answer โโ Line the cavities surrounding freely moveable joints. Eccrine glands produce: -- Answer โโ Sweat containing mostly water. Why are eyelashes shorter than terminal hairs on the scalp? -- Answer โโ The growth stage of an eyelash is shorter. What can a deficiency of growth hormone during bone formation cause? -- Answer โโ Inadequate formation and calcification of bone.
Place the following events of muscle excitation in the correct order.
- Ion channels on the sarcolemma open and sodium ions enter the muscle fiber.
- The entry of sodium ions into the muscle fiber depolarizes the sarcolemma locally.
- ACh is released from vesicles in the motor neuron into the synaptic cleft.
- An action potential arrives at the axon terminal of a motor neuron.
- ACh binds to ligand-gated sodium ion channels in the motor end plate. -- Answer โโ 4, 3, 5, 1, 2 Through which ATP-generating mechanism can long-lasting muscle contractions be sustained? -- Answer โโ Oxidative catabolism Which fibers dominate many of the back and calf muscles that contract almost continually to maintain posture? -- Answer โโ Slow-twitch What is the functional contractile unit of the myofibril? -- Answer โโ Sarcomere Latrotoxin, produced by the poisonous black widow spider, increases the release of acetylcholine. How do muscle cells respond? -- Answer โโ Muscle cells will experience fused or complete tetanus when excess ACh exists. A single motor neuron together with all the skeletal muscle fibers it innervates is called a: -- Answer โโ Motor unit Which statement best describes the function of myoglobin? -- Answer โโ Myoglobin stores oxygen in muscle cells.
What is accomplished by the power stroke? -- Answer โโ The power stroke results in myosin heads pulling actin toward the center of the sarcomere. What does the depolarization of the transverse tubules (T-tubules) promote? -- Answer โโ Release of calcium from the sarcoplasmic reticulum. The type of contraction in which length of the muscle fibers do not change is called: -- Answer โโ Isometric What happens when troponin and tropomyosin block the active sites of actin? -- Answer โโ The muscle relaxes. The increase in muscle tension that is produced by increasing the number of active motor units is called: -- Answer โโ Recruitment Where should most of the potassium ions be located when a muscle cell is at rest? -- Answer โโ Cytosol of the muscle cell The storage and release of calcium ions is the key function of the: -- Answer โโ Sarcoplasmic reticulum Which of the following promotes the depolarization stage? -- Answer โโ Opening of voltage-gated sodium ion channels and sodium ions enter the cell. A drug that inhibited ACh would result in: -- Answer โโ Enhanced stimulation of the muscle due to decreased ACh breakdown.
Which statement best describes the all-or-none principle? -- Answer โโ An action potential happens completely, or it doesn't happen at all. When is the generation of an action potential in a neuron impossible, no matter the strength of the stimulus? -- Answer โโ Absolute refractory period Glial cells differ from neurons in that they: -- Answer โโ Are smaller and capable of mitosis. Which of the following is an effect of myelination? -- Answer โโ Myelination increases the speed of conduction of action potentials. If the receptor site for a neurotransmitter were completely blocked: -- Answer โโ Synaptic transmission would fail. The hyperpolarization that occurs at the end of a neuron action potential is due to prolonged: -- Answer โโ Open state of voltage-gated potassium channels. Upon entering your house, you noticed the smell of cake baking in the oven. What division of the peripheral nervous system is responsible? -- Answer โโ Somatic sensory division If a second EPSP arrives at a synapse before the effects of the first EPSP have disappeared, what is the result? -- Answer โโ Temporal summation
What specific part of the neuron communicates with a target cell and serves as the secretory region of the cell? -- Answer โโ Axon terminals (synaptic knobs) In saltatory conduction along an axon, action potentials are generated: -- Answer โโ Only at Nodes of Ranvier of myelinated axons. A series of measurements with a voltmeter show a neuron's membrane potential becoming more negative, from - 70 mV to - 85mV. This neuron is experiencing a: -- Answer โโ Hyperpolarization phase. What is the most important excitatory neurotransmitter in the central nervous system? -- Answer โโ Glutamate Voltage-gated sodium channels are activated: -- Answer โโ Only if the cell is depolarized to threshold. Which neuroglial cell helps form the blood-brain barrier? -- Answer โโ Astrocyte Sarah sensed a mosquito land on her arm and swatted it away with her hand. Which specific PNS division was responsible for the movement of Sarah's hand? -- Answer โโ Somatic motor division What ion triggers synaptic vesicles to release neurotransmitters into the synaptic cleft? -
Select the correct statement about isotopes. -- Answer โโ Isotopes of the same element have the same atomic number but differ in their mass number. What is a gradient? -- Answer โโ More of something exists in one area than another and the two areas are connected. Building blocks of organic molecules are known as: -- Answer โโ Monomers The two body systems that regulate homeostasis are the: -- Answer โโ Nervous & endocrine systems The four most common elements, comprising 96% of the body's mass, are: -- Answer โโ Oxygen, Nitrogen, Hydrogen, Carbon What is NOT a function of the plasma membrane? -- Answer โโ All of the above are functions of the plasma membrane. Cellular swelling is likely to occur when blood cells are immersed in: -- Answer โโ Hypotonic solutions A mother breastfeeds her infant. As long as the baby suckles his mother's breast, the mother's mammary glands produce milk. Suckling, the stimulus, increases milk production, the response. This scenario is best described as: -- Answer โโ A positive feedback loop
Ions with a net negative charge are called _____________, while ions with a net positive charge are called ____________. -- Answer โโ Anions, cations Which of the following is an example of potential energy? -- Answer โโ Hydrogen ions stored on one side of a cell membrane. During osmosis, water moves toward: -- Answer โโ The highest solute concentration Blood is a mixture that contains insoluble particles that are large enough to be visible, such as blood cells and platelets. Blood is a ______________. -- Answer โโ Suspension When you go outside on a hot summer day, your body temperature rises above the normal range. Receptors in your brain detect the change in temperature. The brain activates nerve cells that send messages to sweat glands, causing the body temperature to fall as the sweat evaporates from the skin. What part of this feedback loop is the effector? -- Answer โโ Sweat glands You have a young cousin that is constantly tired, fatigues easily, and does not seem to have good energy levels. After several tests, doctors determine that one of your cousin's organelles is not functioning properly. Which organelle is most likely affected? -- Answer โโ Mitochondria Place the following in correct sequence from simplest to most complex:
- molecules
- atoms
- tissues
Which of the following is the strongest bond? -- Answer โโ Covalent Simple diffusion requires: -- Answer โโ A concentration gradient The process of digesting food breaks large food particles into smaller particles. This example is best described as a: -- Answer โโ Catabolic reaction Enzymes are composed of what organic molecule? -- Answer โโ Proteins Which organelle modifies, sorts, and packages proteins and lipids for export from the cell? -- Answer โโ Golgi apparatus Which statement best describes enzyme function? -- Answer โโ Enzymes speed chemical reactions by lowering the activation energy. When you go outside on a hot summer day, your body temperature heats up above the normal range. Receptors in your brain detect the change in body temperature. The brain activates nerve cells that send messages to sweat glands, causing the body temperature to fall as the sweat evaporates from the skin. What part of this feedback loop is the stimulus? -- Answer โโ Increased body temperature Which of the following does not characterize proteins? -- Answer โโ They appear to be the molecular carriers of coded hereditary information.
