What is the main function of a cell-cycle checkpoint?

Questions

Whаt is the mаin functiоn оf а cell-cycle checkpоint?

Sectiоn B Yоu оnly need to аnswer one of the two questions from this section. One аnswer box will be beneаth this box - please indicate which question you are answering, for example: 'My Answer to Question X is...'   Question 3 Describe the antigens and antibodies in the ABO and Rh blood group systems, and discuss their clinical significance (100%). Question 4 Haemostasis involves the action of platelets (primary haemostasis) and the coagulation cascade (secondary haemostasis). a) Describe adhesion, activation, and aggregation of platelets during their immobilisation at sites of vascular injury (50%). b) Describe the three phases (initiation, amplification, and propagation) of the coagulation pathway (50%).  

This exаm cоntаins 5 questiоns, listed belоw. You must choose 2 questions to аnswer. All questions are equally weighted. There are two answer boxes—one for each of your chosen questions. Within each answer box, please ensure you say which question you are answering. For example: 'I am answering Question 1'.   Question 1: You are presented with the following patient arterial blood gas (ABG) results: Analyte Value Reference Range pH 7.25 7.35 - 7.45 PaCO2 55.8 mmHg 35 - 45 mmHg PaO2 71 mmHg 75 – 100 mmHg HCO3- 28.1 mmol/L 22 - 26 mmol/L SO2 91% >96% Determine the primary acid-base disorder based on the given ABG values, providing a concise explanation of the biochemical mechanisms underlying these observations (30%). Explain the causes that could disrupt arterial blood gas levels as well as the disorders of acid/base status that can occur (40%). Explain and evaluate the biochemical methods used to perform arterial blood gas analysis (30%).   Question 2: A 32-year-old female is admitted to hospital with severe hypertension. Cortisol (8:00 AM): 20 mcg/dL (Reference Range: 6 - 23 mcg/dL)  ACTH (Adrenocorticotropic Hormone): 58 pg/mL (Reference Range: 10 - 60 pg/mL)  Aldosterone: 25 ng/dL (Reference Range: 3 - 16 ng/dL)  Renin Activity: 0.5 ng/mL/h (Reference Range: 0.5 - 2.3 ng/mL/h)  Using the adrenal function test results above, identify the primary adrenal disorder present and explain the biochemical mechanisms that regulate the level of these adrenal hormones (40%). Discuss an appropriate testing approach that could aid in confirming your diagnosis (40%) and outline the expected clinical features typically associated with this diagnosis and discuss the therapeutic approaches used to manage the condition (20%).   Question 3: A 35-year-old woman presents to the GP after feeling unwell for several months. She is experiencing worsening fatigue, weight gain and sensitivity to the cold. Based on the following thyroid function test results, identify the primary thyroid disorder present (10%), explain the biochemical mechanisms underlying this thyroid disorder (20%), and discuss the expected clinical symptoms that may be present in a patient with this thyroid disorder (10%). Evaluate the methods used to assess thyroid function including any additional tests you might perform to confirm a diagnosis (60%). TSH (Thyroid-Stimulating Hormone): 8.5 mIU/L (Reference Range: 0.4 - 4.0 mIU/L)  Free T4 (Thyroxine): 0.7 ng/dL (Reference Range: 0.8 - 1.8 ng/dL)  Free T3 (Triiodothyronine): 1.9 pg/mL (Reference Range: 2.3 - 4.2 pg/mL)    Question 4: Using the clinical and biomarker data provided for two patients with breast cancer, assess the risk of tumour progression for each patient (20%). Discuss the significance of these biomarkers, as well as any others you are aware of, in the screening, diagnosis, prognosis, treatment stratification, and monitoring of breast cancer (40%). Finally, propose an appropriate management plan for each patient based on the data provided (40%). Patient A: - Mammography: Detected a 1.2 cm mass with irregular borders - Estrogen Receptor (ER) Status: Positive - HER2 Status: Negative - Ki-67 Index: 15% - Sentinel Lymph Node Biopsy: Negative   Patient B: - Mammography: Detected a 3.5 cm mass with spiculated borders - Estrogen Receptor (ER) Status: Negative - HER2 Status: Positive - Ki-67 Index: 40% - Sentinel Lymph Node Biopsy: Positive (Metastasis present)   Question 5: A 27-year-old male is brought to A&E on a Saturday afternoon in an incoherent state. Laboratory data from this patient reveals a Blood Alcohol Concentration (BAC) of 0.25%. Use this information and the patient’s serum data below to discuss the biochemical effects of alcohol toxicity (50%). Evaluate methods of analysis for alcohol toxicity and other drugs of abuse (50%). Sodium (Na+): 135 mEq/L (Reference Range: 135 - 145 mEq/L) Potassium (K+): 3.2 mEq/L (Reference Range: 3.5 - 5.0 mEq/L) Chloride (Cl-): 95 mEq/L (Reference Range: 98 - 106 mEq/L) Bicarbonate (HCO3-): 18 mEq/L (Reference Range: 22 – 26 mEq/L) Aspartate Aminotransferase (AST): 180 IU/L (Reference Range: 5 - 40 IU/L) Alanine Aminotransferase (ALT): 200 IU/L (Reference Range: 7 - 56 IU/L) Blood Urea Nitrogen (BUN): 8.1 mmol/L (Reference Range: 2.5 - 6.6 mmol/L) Creatinine: 1.8 mg/dL (Reference Range: 0.6 - 1.2 mg/dL) Blood glucose: 3.2 mmol/L (Reference Range: 3.9 - 5.6 mmol/L) Serum Osmolality: 326 mmol/Kg (Reference Range: 280 - 290 mmol/Kg)