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Question 1
Correct
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Mitosis is the process of cell division which culminates in cell chromosomes which are:
Your Answer: Diploid
Explanation:Mitosis is a part of the cell cycle when replicated chromosomes are separated into two new diploid nuclei.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 2
Incorrect
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Regarding integrins, which option is false?
Your Answer: Principally bind to ECM components such as fibrinogen, elastase and laminin
Correct Answer: Play no role in cell signalling.
Explanation:Integrins are transmembrane receptors that facilitate cell-extracellular matrix (ECM) adhesion. Upon ligand binding, integrins activate signal transduction pathways that mediate cellular signals such as regulation of the cell cycle, organization of the intracellular cytoskeleton, and movement of new receptors to the cell membrane. Integrins are obligate heterodimers, meaning that they have two subunits: α (alpha) and β (beta). Integrins play an important role in cell signalling by modulating the cell signalling pathways of transmembrane protein kinases such as receptor tyrosine kinases (RTK).
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 3
Incorrect
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Which of the following statements is most suitable to describe necrosis?
Your Answer: Tightly regulated involving activation and enzymatic steps.
Correct Answer: Significant inflammatory response
Explanation:Necrosis is the death of most or all of the cells in an organ or tissue due to disease, injury, or failure of the blood supply. Cellular death due to necrosis does not follow the (regulated) apoptotic signal transduction pathway, but rather various receptors are activated, and result in the loss of cell membrane integrity and an uncontrolled release of products of cell death into the extracellular space. This initiates in the surrounding tissue an inflammatory response which attracts leukocytes and nearby phagocytes which eliminate the dead cells by phagocytosis.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 4
Incorrect
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Regarding oxidative deamination of amino acids, which of the following is true?
Your Answer: Leads to the formation of ribose
Correct Answer: Occurs in the kidney & liver
Explanation:Oxidative deamination is a form of deamination that generates α-keto acids and other oxidized products from amine-containing compounds, and occurs largely in the liver and kidney. Oxidative deamination is an important step in the catabolism of amino acids, generating a more metabolizable form of the amino acid, and also generating ammonia as a toxic by-product. The addition of ubiquitin to a substrate protein is called ubiquitination.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 5
Incorrect
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Which one of the following is able to move across cell membranes by passive diffusion?
Your Answer: Ca2+
Correct Answer: CO2
Explanation:The cell membrane is permeable to water molecules and a few other small, uncharged, molecules like oxygen (O2) and carbon dioxide (CO2). Larger molecules like glucose or charged ions are unable to cross passively.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 6
Incorrect
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Which ion channel is a dimer?
Your Answer: K+ channel
Correct Answer: Cl- channel
Explanation:A dimer is a chemical structure formed from two similar sub-units. Chloride channels or exchangers are composed of two similar subunits—a dimer—each subunit containing one pore.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 7
Incorrect
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With regards to the cell cycle, which phase represents period of cell growth that divides the end of DNA synthesis and the beginning of somatic cell division?
Your Answer: Metaphase
Correct Answer: Gap 2
Explanation:Interphase is divided into three phases: G1 (first gap), S (synthesis), and G2 (second gap). During all three parts of interphase, the cell grows by producing proteins and cytoplasmic organelles. However, chromosomes are replicated only during the S phase. Thus, a cell grows (G1), continues to grow as it duplicates its chromosomes (S), grows more and prepares for mitosis (G2), and finally divides (M) before restarting the cycle.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 8
Incorrect
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The complete oxidation of 1 molecule of glucose to CO2 and H20 produces a total of __ATP.
Your Answer: 28
Correct Answer: 38
Explanation:Textbooks often state that 38 ATP molecules can be made per oxidised glucose molecule during cellular respiration (2 from glycolysis, 2 from the Krebs cycle, and about 34 from the electron transport system). However, this maximum yield is never quite reached because of losses due to leaky membranes as well as the cost of moving pyruvate and ADP into the mitochondrial matrix, and current estimates range around 29 to 30 ATP per glucose.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 9
Incorrect
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In the body what are fatty acids broken down to?
Your Answer: Aceto acetate
Correct Answer: Acetyl Co A
Explanation:Fatty acids are broken down into acetyl Co A. The acetyl-CoA produced by beta oxidation enters the citric acid cycle in the mitochondrion by combining with oxaloacetate to form citrate.
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This question is part of the following fields:
- Cell Biology
- Medicine
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Question 10
Incorrect
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Inhibition of cell division at the end of G1 occurs through:
Your Answer:
Correct Answer: Unphosphorolated retinoblastoma protein (uRb)
Explanation:A cell’s decision to enter, or re-enter, the cell cycle is made before S-phase in G1 at what is known as the restriction point, and is determined by the combination of promotional and inhibitory extracellular signals that are received and processed. Ultimately unphosphorylated Rb acts as an inhibitor of G1.
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This question is part of the following fields:
- Cell Biology
- Medicine
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SESSION STATS - PERFORMANCE PER SPECIALTY
