Week Two Quiz

The quiz is divided into two sections. The first section contains questions that assess your recall of essential biological facts. The second set of questions asks you to apply your knowledge of material presented to solve clinical or research problems. The questions in the second set are similar to what you will encounter on the self-assessment and qualifier.

Instructions: To check your answer, click on the option you think is correct.

Recall Questions

  1. Which of the following is the primary molecule used by cells to store and transfer energy?

    1. Glucose
    2. ATP
    3. NADH
    4. Pyruvate
  2. Which molecule acts as the final electron acceptor in the electron transport chain?

    1. Oxygen
    2. NADH
    3. FADH2
    4. Carbon Dioxide
  3. Which molecule acts as the final electron acceptor in the electron transport chain?

    1. Oxygen
    2. NADH
    3. FADH2
    4. Carbon Dioxide
  4. Which of the following reactions is an example of a coupled reaction?

    1. Glucose + Oxygen → CO2 + Water
    2. ATP + Glucose → ADP + Glucose-6-phosphate
    3. Pyruvate → Lactate
    4. ADP + Pi → ATP
  5. The conversion of NAD+ to NADH during glycolysis is an example of which type of process?

    1. Phosphorylation
    2. Oxidation
    3. Reduction
    4. Hydrolysis
  6. NADPH is primarily involved in which type of cellular processes?

    1. Catabolic
    2. Anabolic
    3. Glycolytic
    4. Fermentation
  7. What is the role of transfer RNA (tRNA) in translation?

    1. To unwind the DNA double helix
    2. To match amino acids with the mRNA codons
    3. To synthesize RNA from a DNA template
    4. To match amino acids with the mRNA codons
  8. What is the significance of the start codon in mRNA?

    1. It marks the end of translation.
    2. It signals the beginning of transcription.
    3. It indicates the start of protein synthesis.
    4. It is responsible for mRNA splicing.
  9. What is a mutation or variant?

    1. A change in the amino acid sequence of a protein
    2. A change in the DNA sequence of a gene
    3. A modification in the RNA sequence of a transcript
    4. A change in the ribosomal RNA during translation
  10. What is the function of a promoter in gene expression?

    1. To initiate the translation
    2. To signal the end of transcription
    3. To provide a binding site for RNA polymerase and other transcription factors
    4. To stabilize the mRNA molecule
  11. What is the primary function of the 5' cap and poly-A tail in eukaryotic mRNA?

    1. To facilitate the export of mRNA from the nucleus
    2. To stabilize the mRNA and protect it from degradation
    3. To aid in the correct folding of the mRNA
    4. To enhance the transcription of the gene

Application Questions

  1. PTH stimulates osteoblasts to synthesize RANKL (RANK ligand). If you analyzed histones on the RANKL gene in osteoblasts after addition of PTH, what change would you expect?

    1. Acetylated histones
    2. Deacetylated histones
    3. More histones
    4. Fewer histones

    Show Explanation

  2. Bisphosphanates are often used to treat osteoporosis. The structure of a typical bisphosphanate is shown below. They contain phosphate groups and chemical groups that induce apoptosis? The effectiveness of bisphosphanates in increasing bone density depends on which activity in osteoclasts.

    1. Acid secretion
    2. Collagenase secretion
    3. RANK receptor expression
    4. Endocytosis

    Show Explanation

  3. Although bisphosphanates are often used to treat osteoporosis, some recent studies have linked long-term use of bisphosphanates (> 3 years) with an increase risk of fractures in the femur. What might explain the increase in fractures associated with long-term use of bisphosphanates?

    1. Decrease endochondrial ossification
    2. Decrease intramembraneous ossification
    3. Decrease in bone modeling
    4. Decrease in bone remodeling

    Show Explanation

  4. In addition to collagen, osteoblasts also secrete osteopontin which contains a domain that interacts with integrins. Loss of osteopontin is also associated with decrease in bone strength. What best explains osteopontin's role in bone metabolism?

    1. Attachment of osteoclasts to bone
    2. Collagen secretion
    3. Calcium-phosphate crystallization
    4. Collagenase activation

    Show Explanation

  5. You are studying different muscle tissue and measuring the rate at which each contracts. To initiate contraction, you apply an electrical stimulus to each muscle type. You notice that smooth muscle starts to contract much longer after stimulation than skeletal and cardiac muscle. What accounts for this delayed response in smooth muscle cells?

    1. Slower rate of myosin activation
    2. Slower rate of calcium channels opening
    3. Slower rate of tropomyosin movement
    4. Slower rate of sodium channels opening

    Show Explanation

  6. You are working with a neurologist to identify biopsies that show damage to motor neurons that innervate skeletal muscle cells. The biopsies show axons of several different types, and you must quickly identify axons which are most likely part of a motor neuron. Which type would you look for?

    1. 1 µm diameter, unmyelinated
    2. 1 µm diameter, myelinated
    3. 10 µm diameter, myelinated
    4. 10 µm diameter, unmyelinated

    Show Explanation

  7. Alport Syndrome is caused by mutations in a gene that encodes a type IV collagen. The disease mostly likely affects which of the following?

    1. Long bones
    2. Achilles tendon
    3. Kidney epithelium
    4. Knee cartilage

    Show Explanation

  8. You run a routine blood test on a patient, and the results show hypomagnesium (low serum magnesium). Urinalysis reveals above normal levels of magnesium. Genome sequencing shows a mutation in claudin 19. Through which pathway does magnesium pass across the epithelium in the kidney?

    1. Magnesium channel
    2. Transcytosis
    3. Paracellular diffusion
    4. Magnesium pump

    Show Explanation

  9. Assuming most magnesium is reabsorbed in the kidney through the paracellular route, which channel would epithelial cells in the kidney express in their apical membrane to create the driving force to absorb magnesium from the lumen of the kidney tube into the interstitial fluid?

    1. Sodium channel
    2. Chloride channel
    3. Potassium channel
    4. Calcium pump

    Show Explanation

  10. You are working with a group of people who worked several years as firefighters for US Forest Service. Many of the people in the group show signs of respiratory disease, including emphysema and obstructive lung disease. You have been asked to screen biopsies for the evidence of obstructive lung disease which can be diagnosed by a change in the epithelia of bronchioles from a normal simple columnar. Below is image of a bronchiole from a biopsy. How would you characterize the epithelium?

    1. Normal
    2. Hyperplastic
    3. Metaplastic
    4. Dysplastic

    Show Explanation

  11. You are studying an inherited form of muscle weakness. You identify a mutation in a gene that encodes a potassium channels. The mutation increases the probability that the channel is open. You analyze the electrophysiology of the skeletal muscle cells from the affected patients and discover that the muscle cells require higher concentrations of acetylcholine to generate contraction. What is the most likely explanation for the change in the skeletal muscle cells?

    1. Increase in amount of acetylcholine receptors
    2. Increase in the threshold potential
    3. Increase in the overshoot potential
    4. Increase in membrane potential

    Show Explanation