00
Correct
00
Incorrect
00 : 00 : 00
Session Time
00 : 00
Average Question Time ( Secs)
  • Question 1 - What is the primary reason for malnutrition? ...

    Incorrect

    • What is the primary reason for malnutrition?

      Your Answer: Inadequate intake of multiple minerals

      Correct Answer: Inadequate intake of calories in any form

      Explanation:

      Malnutrition

      Malnutrition refers to a state where the dietary intake is insufficient to maintain a healthy state and stable weight. It can be caused by over- or under-nutrition, but it is commonly used to describe under-nutrition. Malnutrition can be defined as a state of nutrition where a deficiency, excess, or imbalance of energy, protein, and other nutrients causes measurable adverse effects on tissue, function, and clinical outcome. Protein malnutrition is the most severe form of malnutrition, causing significant mortality and clinical effects such as kwashiorkor. Carbohydrate malnutrition is less common as carbohydrate sources are widely grown and cheap. Fat malnutrition rarely results in problems if there is adequate dietary protein and carbohydrate. Deficiencies of fat-soluble vitamins can result in various clinical effects. Body size can give some indication of nutritional status, but many obese patients may have nutritional deficiencies due to their faddy diets.

    • This question is part of the following fields:

      • Basic Sciences
      13
      Seconds
  • Question 2 - A premature baby is born and the anaesthetists are struggling to ventilate the...

    Correct

    • A premature baby is born and the anaesthetists are struggling to ventilate the lungs because of insufficient surfactant. How does Laplace's law explain the force pushing inwards on the walls of the alveolus caused by surface tension between two static fluids, such as air and water in the alveolus?

      Your Answer: Inversely proportional to the radius of the alveolus

      Explanation:

      The Relationship between Alveolar Size and Surface Tension in Respiratory Physiology

      In respiratory physiology, the alveolus is often represented as a perfect sphere to apply Laplace’s law. According to this law, there is an inverse relationship between the size of the alveolus and the surface tension. This means that smaller alveoli experience greater force than larger alveoli for a given surface tension, causing them to collapse first. This phenomenon is similar to what happens when two balloons of different sizes are attached together, with the smaller balloon emptying into the larger one.

      In the lungs, this collapse of smaller alveoli can lead to atelectasis and collapse if surfactant is not present. Surfactant is a substance that reduces surface tension, making it easier to expand the alveoli and preventing smaller alveoli from collapsing. this relationship between alveolar size and surface tension is crucial in respiratory physiology, as it helps explain the importance of surfactant in maintaining proper lung function.

    • This question is part of the following fields:

      • Basic Sciences
      19.1
      Seconds
  • Question 3 - What are the clinical effects that can occur due to acute or chronic...

    Correct

    • What are the clinical effects that can occur due to acute or chronic over-administration of multivitamins leading to Vitamin A toxicity?

      Your Answer: Nausea, vomiting and headaches

      Explanation:

      The Importance and Risks of Vitamin A

      Vitamin A is an essential nutrient that plays a crucial role in various bodily functions such as growth and development, vision, enzyme signalling pathways, and the maintenance of epithelial membranes. However, excessive intake of vitamin A can lead to toxicity, which can cause several adverse effects. These include raised intracranial pressure resulting in headaches, nausea, vomiting, and visual loss, increased bone resorption leading to osteoporosis and hypercalcaemia, liver damage, hair loss, and skin changes. Moreover, there is a possible increased risk of malignancy, particularly among smokers. Pregnant women are also advised to avoid foods rich in vitamin A, such as liver and fish oils, due to the teratogenicity of vitamin A-derived drugs. Therefore, it is crucial to maintain a balanced intake of vitamin A to avoid the risks associated with its toxicity.

    • This question is part of the following fields:

      • Basic Sciences
      20.7
      Seconds
  • Question 4 - Which statement regarding microtubules is accurate in relation to Chédiak-Higashi syndrome? ...

    Incorrect

    • Which statement regarding microtubules is accurate in relation to Chédiak-Higashi syndrome?

      Your Answer:

      Correct Answer: They are arranged in a 9+2 formation in cilia

      Explanation:

      Microtubules and Chédiak-Higashi Syndrome

      Microtubules are made up of alpha and beta tubulin dimers that are arranged in a helix and can be added or removed to change the length. They are found in structures such as flagella, mitotic spindles, and cilia, where they have a 9+2 arrangement. These structures are important for cell movement and division. Chemotherapy agents, such as taxanes, target microtubules and are used in breast cancer treatment.

      Chédiak-Higashi syndrome is a rare inherited immunodeficiency disorder caused by mutations in the LYST gene. This condition is characterized by neutrophil inclusions, albinism, recurrent infections, and peripheral neuropathy. The neutrophil inclusions are thought to be caused by abnormal microtubule function, which affects the immune system’s ability to fight infections. While there is no cure for Chédiak-Higashi syndrome, treatment focuses on managing symptoms and preventing infections.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 5 - What is the conversion of pyruvate before it enters the Krebs cycle? ...

    Incorrect

    • What is the conversion of pyruvate before it enters the Krebs cycle?

      Your Answer:

      Correct Answer: Acetyl-CoA

      Explanation:

      The Krebs cycle occurs in the mitochondrion and involves the conversion of acetyl-CoA to oxaloacetate. This cycle produces six NADH, two FADH, and two ATP for each molecule of glucose. Pyruvate is converted to acetyl-CoA before entering the Krebs cycle, and water and carbon dioxide are end products. Acetic acid itself has no role in the cycle, but its acetyl group is used to form acetyl-CoA. Some anaerobic bacteria can convert sugars to acetic acid directly.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 6 - You encounter a patient in the Emergency department who has been in a...

    Incorrect

    • You encounter a patient in the Emergency department who has been in a severe car accident. You need to insert a venous cannula for aggressive fluid resuscitation. Applying the Hagen-Poiseuille equation, you select a cannula with appropriate dimensions for maximum flow into the vein.
      As per this law, which of the following statements is correct?

      Your Answer:

      Correct Answer: Flow will be faster through a shorter cannula

      Explanation:

      Poiseuille’s Equation and Fluid Flow in Cylinders

      Poiseuille’s equation is used to describe the flow of non-pulsatile laminar fluids through a cylinder. The equation states that the flow rate is directly proportional to the pressure driving the fluid and the fourth power of the radius. Additionally, it is inversely proportional to the viscosity of the fluid and the length of the tube. This means that a short, wide cannula with pressure on the bag will deliver fluids more rapidly than a long, narrow one.

      It is important to note that even small changes in the radius of a tube can greatly affect the flow rate. This is because the fourth power of the radius is used in the equation. Therefore, any changes in the radius will have a significant impact on the flow rate. Poiseuille’s equation is crucial in determining the optimal conditions for fluid delivery in medical settings.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 7 - What are the typical clinical manifestations of a deficiency in vitamin B6 (pyridoxine)?...

    Incorrect

    • What are the typical clinical manifestations of a deficiency in vitamin B6 (pyridoxine)?

      Your Answer:

      Correct Answer: Sensory neuropathy

      Explanation:

      The Importance of Pyridoxine in the Body

      Pyridoxine is a group of B-vitamins that are crucial in various bodily functions. They act as essential cofactors in many reactions, particularly in the metabolism of amino acids and neurotransmitters. Pyridoxine also plays a role in regulating gene transcription and controlling steroid hormones.

      The body can produce pyridoxine through bacterial flora in the gut, and it is also present in many dietary sources. However, overheating certain foods can destroy pyridoxine, and some medications can alter its metabolism. Pyridoxine is also used therapeutically to prevent neuropathy in the treatment of tuberculosis.

      Deficiency in pyridoxine can lead to sensory neuropathy, skin changes, and damage to mucous membranes. On the other hand, deficiency in vitamin C can cause gingivitis and increased bleeding, while vitamin K deficiency can also lead to bleeding. Sleep disturbance is rarely attributed to vitamin B3 (niacin) deficiency.

      In summary, pyridoxine is a vital nutrient that plays a crucial role in various bodily functions. Its deficiency can lead to various health problems, highlighting the importance of maintaining adequate levels of this vitamin in the body.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 8 - In scientific experimentation, what is the term used to describe the movement of...

    Incorrect

    • In scientific experimentation, what is the term used to describe the movement of charged particles or solutes in a liquid medium due to an electric field?

      Your Answer:

      Correct Answer: Electrophoresis

      Explanation:

      Electrophoresis: Separating Molecules Based on Charge and Mass

      Electrophoresis is a technique that separates solutes, molecules, or nucleic acids based on their mass and charge. It involves the migration of charged particles in a liquid medium under the influence of an electric field. The apparatus consists of two electrodes placed at either end of a support medium, or gel, which is suspended in a buffer solution. The sample is inserted into a well and a current is applied. Over time, positively charged solutes move towards the negative electrode, while negatively charged substances move towards the positive electrode. Once the migration is complete, the gel is removed and stained to color the substance being tested for, such as protein.

      This technique is widely used in medical testing, but it requires a higher degree of operational and interpretive skill than many other tests, which is why it often takes longer to get a result. Electrophoresis has various uses and adaptations, such as standard electrophoresis for protein detection in the diagnosis of myeloma, identification of unusual lipid fractions in patients with inherited diseases, and detection of viral DNA through Southern Blotting. There is also Northern blotting, primarily a research technique at present, which uses electrophoresis to separate RNA. Additionally, Western blotting is used to test for the presence of antibodies to DNA through protein separation.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 9 - A 65-year-old patient with suspected spinal cord compression has been admitted to the...

    Incorrect

    • A 65-year-old patient with suspected spinal cord compression has been admitted to the neurosurgical team for an urgent MRI of the spine. Which particle's magnetic properties does magnetic resonance imaging rely predominantly upon?

      Your Answer:

      Correct Answer: Hydrogen ion (proton)

      Explanation:

      How MRI Scanners Use Hydrogen Ions to Create Images

      MRI scanners use the magnetic properties of hydrogen ions, also known as protons, to create images of the human body. These protons have nuclear spin, which means they have magnetic vectors that can be aligned in an electromagnet. The scanner bombards the protons with radiofrequency radiation, causing them to release energy when they return to their resting state. This energy release is recorded and used to construct the MRI image.

      While other nuclei, such as carbon 13, also have nuclear spin and could be used in MRI imaging, hydrogen ions are much more abundant in human tissues. This makes them the preferred choice for creating images of the body. The process of aligning the magnetic vectors of the protons and then recording their energy release is repeated many times to create a detailed image of the body’s internal structures.

      Overall, MRI scanners use the magnetic properties of hydrogen ions to create detailed images of the human body. This non-invasive imaging technique has revolutionized medical diagnosis and treatment, allowing doctors to see inside the body without the need for surgery.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 10 - To what type of cell can mesenchymal stem cells transform? ...

    Incorrect

    • To what type of cell can mesenchymal stem cells transform?

      Your Answer:

      Correct Answer: Osteoblasts

      Explanation:

      Mesenchymal Cells: The Stem Cells of the Human Skeleton

      Mesenchymal cells are the primary stem cells of the human skeleton. These multipotent cells originate in the bone marrow and have the ability to differentiate into various cell types. Osteoblasts, responsible for bone formation, chondrocytes, which give rise to cartilage, and adipocytes, specialized in storing energy as fat, are some of the cells that mesenchymal cells can produce. Muscle cells, or myocytes, arise from muscle satellite cells, while skin cells come from epithelial stem cells. Neurons mostly arise from neural stem cells, although some may come from astrocytes. White blood cells, on the other hand, come from hematopoietic stem cells. Mesenchymal cells play a crucial role in the maintenance and repair of the human skeleton, making them an essential area of study in regenerative medicine.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 11 - Which statement regarding microtubules is accurate in relation to Chediak-Higashi syndrome? ...

    Incorrect

    • Which statement regarding microtubules is accurate in relation to Chediak-Higashi syndrome?

      Your Answer:

      Correct Answer: They are arranged in a 9+2 formation in cilia

      Explanation:

      Microtubules and Chediak-Higashi Syndrome

      Microtubules are structures composed of alpha and beta tubulin dimers that are arranged in a helix and can be added or removed to vary the length. They are found in flagella, mitotic spindles, and cilia, where they have a 9+2 arrangement. Chemotherapy agents, such as taxanes, target microtubules in breast cancer treatment.

      Chediak-Higashi syndrome is an autosomal recessive condition that presents with albinism, bleeding and bruising due to platelet dysfunction, and susceptibility to infections due to abnormal neutrophils. The LYST gene is responsible for lysosomal trafficking proteins and is affected in this syndrome.

      In summary, microtubules are important structures in various cellular processes and are targeted in cancer treatment. Chediak-Higashi syndrome is a rare genetic disorder that affects lysosomal trafficking proteins and presents with various symptoms.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 12 - What is the primary factor that increases the risk of thiamine (vitamin B1)...

    Incorrect

    • What is the primary factor that increases the risk of thiamine (vitamin B1) deficiency?

      Your Answer:

      Correct Answer: Chronic alcohol excess

      Explanation:

      Thiamine: Its Roles, Sources, Deficiency States, and Manifestations

      Thiamine is a vital nutrient that plays several roles in the body. It acts as a cofactor to enzymes involved in energy production, metabolism of branched chain amino acids, and regulation of nerve and muscle action potentials. It is found in many foods, including wheat, oats, and yeast-containing products. However, deficiency states can occur in chronic alcohol dependence, renal dialysis, and cultures that mainly consume white rice. The deficiency can manifest as ‘dry’ beriberi, which causes peripheral neuropathy, muscle weakness, fatigue, and reduced concentration, or ‘wet’ beriberi, which also involves heart failure and edema. In severe cases, Wernicke-Korsakoff syndrome can develop, which is an emergency requiring urgent IV replacement of thiamine. If left untreated, it can lead to irreversible amnesia, confabulation, and dementia. Therefore, all patients with alcohol-related admissions should be considered for Pabrinex, a B vitamin infusion.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 13 - What occurs in eukaryotic prophase? ...

    Incorrect

    • What occurs in eukaryotic prophase?

      Your Answer:

      Correct Answer: Chromatin condenses into chromosomes

      Explanation:

      The Stages of Prophase in Eukaryotic Mitosis

      Prophase is the first stage of eukaryotic mitosis, except for plant cells which have a preprophase stage. During prophase, the cell’s chromatin, which is made up of DNA and associated proteins, condenses into double rod-shaped structures called chromosomes. This process is facilitated by the condensin protein I and/or II complexes. As the chromosomes form, the nuclear membrane and nucleoli disintegrate and disappear, making the chromatin visible.

      Before prophase, the cell’s DNA is replicated during interphase, resulting in identical pairs of chromosomes called chromatids. These chromatids attach to each other at a DNA element called the centromere. DNA and centrosome duplication occur during interphase, while chromosome alignment takes place during metaphase. The nuclear membrane and nucleoli re-form during telophase, and the sister chromatids separate during anaphase.

      In summary, prophase is the initial stage of eukaryotic mitosis where chromatin condenses into chromosomes, and the nuclear membrane and nucleoli disappear. Chromosome alignment, DNA and centrosome duplication, and re-formation of the nuclear membrane and nucleoli occur in subsequent stages.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 14 - What role does the nucleolus play in eukaryotic cells? ...

    Incorrect

    • What role does the nucleolus play in eukaryotic cells?

      Your Answer:

      Correct Answer: To transcribe ribosomal RNA and assemble ribosomes

      Explanation:

      The Nucleolus: Structure and Function

      The nucleolus is a non-membrane-bound structure that takes up about a quarter of the nuclear volume. It is composed mainly of proteins and nucleic acids and is responsible for transcribing ribosomal RNA (rRNA) and assembling ribosomes in the cell. Nucleoli are formed in nucleolar organizing regions (NORs), which are also the regions of the genes for three of the four eukaryotic rRNAs.

      During ribosome assembly, ribosomal proteins enter the nucleolus from the cytoplasm and begin to assemble on an rRNA precursor. As the pre-rRNA is cleaved to produce 5.8S, 18S, and 28S rRNAs, additional ribosomal proteins and the 5S rRNA (which is synthesized elsewhere in the nucleus) assemble to form preribosomal subunits. These subunits then exit the nucleolus into the cytoplasm and combine to produce the final 40S and 60S ribosomal subunits.

      Overall, the nucleolus plays a crucial role in protein synthesis by producing the components necessary for ribosome assembly. Its unique structure and function make it an essential component of the cell’s machinery.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 15 - What is the end result of meiosis in a cell? ...

    Incorrect

    • What is the end result of meiosis in a cell?

      Your Answer:

      Correct Answer: 4 haploid cells

      Explanation:

      Meiosis

      Meiosis is a crucial process that occurs in the genetic cells of eukaryotic organisms. Its primary purpose is to recombine genes, which results in genetic variation while also ensuring genetic preservation. Although meiosis shares some similarities with mitosis, it is restricted to genetic cells, also known as gametes, of eukaryotic organisms.

      During meiosis, a gamete duplicates each of its chromosomes and divides into two diploid cells. These cells then divide into four haploid cells by the end of the second stage of meiosis (telophase II and cytokinesis). These haploid cells are either sperm cells (male) or eggs (female) in mammals. When these haploid cells fuse together, they produce a diploid zygote that contains two copies of parental genes.

      In summary, meiosis is a crucial process that ensures genetic variation and preservation in eukaryotic organisms. It involves the duplication and division of genetic cells into haploid cells, which can then fuse together to produce a diploid zygote.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 16 - What is the estimated percentage of oxygen in the blood that is attached...

    Incorrect

    • What is the estimated percentage of oxygen in the blood that is attached to haemoglobin?

      Your Answer:

      Correct Answer: 100%

      Explanation:

      Calculation of Oxygen in Blood

      The majority of oxygen in the blood is bound to haemoglobin, with the exact amount varying based on the oxygen saturation and haemoglobin level. To calculate the amount of oxygen per litre of blood, the formula (13.9 × Hb × sats/100) + (PaO2 × 0.03) can be used. For example, an average man with an Hb of 14, saturations of 98% on room air, and a PaO2 of 12 would have 191 ml of oxygen per litre of blood. It is important to note that only 0.36 ml of this oxygen is dissolved in the blood.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 17 - Over the last five years, the total number of patients admitted and deaths...

    Incorrect

    • Over the last five years, the total number of patients admitted and deaths in the East and North Hertfordshire NHS Trust have been recorded. In the year 2010/2011, there were 95,071 patients admitted and 1,912 deaths. What is the crude mortality ratio for this group in that year (per 100 admissions)?

      Your Answer:

      Correct Answer: 2

      Explanation:

      In this scenario, the crude mortality ratio is established by comparing the number of deaths occurring within the hospital in a given year to the total number of admissions, disregarding age or gender-specific mortality rates. For instance, with 1,912 deaths out of 95,071 admissions, the ratio computes to 0.02, or 2.0% when calculated per 100 admissions (1,912/95,071 = 0.02/100= 2.0%. When recalculated per 1,000 admissions, the crude admission rate would be 20 per 1,000.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 18 - What is the apoptotic event that occurs just before the formation of an...

    Incorrect

    • What is the apoptotic event that occurs just before the formation of an apoptosome?

      Your Answer:

      Correct Answer: Release of cytochrome c from mitochondria

      Explanation:

      Apoptosis and the Role of the Apoptosome

      Apoptosis, also known as programmed cell death, is a natural process that occurs in all multicellular organisms. It involves a series of changes in cell morphology, including membrane blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation. The formation of the apoptosome is a crucial part of the apoptosis cascade. It is a large protein structure that is triggered by the release of cytochrome c from the mitochondria in response to various stimuli, such as DNA damage, infections, or developmental signals.

      The apoptosome is formed when cytochrome c binds to Apaf-1, a cytosolic protein, in a 1:1 ratio. This triggers the recruitment and activation of the initiator pro-caspase-9, which then activates effector caspases, a family of apoptotic proteases, to initiate the apoptotic cascade. It is important to note that the activation of caspase-9 occurs only after the formation of the apoptosome.

      In summary, apoptosis is a natural process that occurs in multicellular organisms, and the apoptosome plays a crucial role in triggering the apoptotic cascade. the mechanisms behind apoptosis and the formation of the apoptosome can provide insights into various diseases and developmental processes.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 19 - During which phase of aerobic respiration is FADH2 generated? ...

    Incorrect

    • During which phase of aerobic respiration is FADH2 generated?

      Your Answer:

      Correct Answer: Krebs cycle

      Explanation:

      The Krebs Cycle and the Role of FADH2

      The Krebs cycle is a crucial part of aerobic respiration in cells. It involves a series of reactions that convert acetate, derived from carbohydrates, fats, and proteins, into carbon dioxide and energy in the form of ATP. Additionally, the Krebs cycle produces precursors for some amino acids and reducing agents like NADH and FADH2 that are involved in other metabolic pathways.

      FAD is a redox cofactor that plays a vital role in the Krebs cycle. It receives two electrons from the sixth reaction of the cycle, where succinate dehydrogenase converts succinate into fumarate by removing two hydrogen atoms and attaching them onto FAD. This process results in FAD gaining two electrons and reducing into FADH2.

      FADH2 then donates the electrons to the electron transport chain, which is another part of cellular respiration. This mechanism helps compensate for the relatively low amount of ATP produced by the Krebs cycle (2.5 molecules of ATP per turn) compared to the electron transport chain (26-28 molecules of ATP). Overall, the Krebs cycle and the role of FADH2 are essential for generating energy in cells.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 20 - What is the main role of the Golgi apparatus in eukaryotic cells? ...

    Incorrect

    • What is the main role of the Golgi apparatus in eukaryotic cells?

      Your Answer:

      Correct Answer: Process of proteins

      Explanation:

      The Golgi Apparatus, Cell Division, and Homeostasis

      The Golgi apparatus is a structure found in eukaryotic cells that consists of flattened membrane stacks. Its primary function is to modify proteins that have been synthesized in the rough endoplasmic reticulum, preparing them for secretion or transport within the cell. However, the Golgi apparatus is not directly involved in cell division, which is controlled by the nucleus.

      Cell homeostasis, on the other hand, is primarily maintained by membrane-embedded channels or proteins such as the sodium-potassium pump. This mechanism ensures that the cell’s internal environment remains stable. The sodium-potassium pump is an active transport mechanism that involves the binding of three intracellular sodium ions to the protein. Adenosine triphosphate (ATP) donates a phosphate group to the protein, which causes it to change shape and release the sodium ions out of the cell.

      The protein then accepts two extracellular potassium ions, and the donated phosphate group detaches, causing the protein to revert to its original shape. This allows the potassium ions to enter the cell, increasing the intracellular potassium concentration and decreasing the intracellular sodium concentration. This process is in contrast to the extracellular conditions.

      In summary, the Golgi apparatus modifies proteins for secretion or transport, while cell division is controlled by the nucleus. Cell homeostasis is maintained by membrane-embedded channels or proteins such as the sodium-potassium pump, which actively transports ions to stabilize the cell’s internal environment.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 21 - What function does vitamin E serve in the body? ...

    Incorrect

    • What function does vitamin E serve in the body?

      Your Answer:

      Correct Answer: Antioxidant

      Explanation:

      Vitamin E and its Functions

      Several substances are classified as vitamin E, with alpha-tocopherol being the most common, accounting for 90% of human vitamin E. Alpha-tocopherol is composed of two carbon rings and a long saturated hydrocarbon chain, making it hydrophobic. It has an aromatic ring with an OH- group attached to it. Other substances with vitamin E activity include other tocopherols and tocotrienols, all of which act as antioxidants. Alpha-tocopherol is particularly important in cell membranes, preventing the peroxidation of unsaturated fatty acids by free radicals. It also has other functions, such as regulating gene transcription, inhibiting clotting formation, reducing proliferation of vascular smooth muscle, and playing a role in immunity.

      Despite claims that taking vitamin E can reduce the risk of heart disease, cancer, and enhance sexual performance, there is currently no strong evidence to support these claims.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 22 - What occurs in eukaryotic prometaphase? ...

    Incorrect

    • What occurs in eukaryotic prometaphase?

      Your Answer:

      Correct Answer: The nuclear membrane and the nucleoli disintegrate and kinetochores appear

      Explanation:

      The Significance of Prometaphase in Cell Division

      Prometaphase is a crucial phase in cell division that marks the transition from prophase to metaphase. Although it is often considered as a part of these two phases, it has distinct events that make it an individual phase. During prometaphase, the nuclear membrane disintegrates, and the nucleoli are no longer visible. Additionally, each chromosome forms two kinetochores near the centromere, which serve as attachment points for spindle fibers. These fibers connect to the opposite poles of the cell, forming travelling lines that will separate the sister chromatids during anaphase.

      Prophase is characterized by chromatin condensation, while DNA and centrosome duplication occur during interphase. Chromosome alignment takes place during metaphase, and the sister chromatids separate during anaphase. Prometaphase, therefore, plays a crucial role in preparing the chromosomes for separation during anaphase. Its distinct events make it an essential phase in cell division, and its proper execution is necessary for successful cell division.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 23 - A 40-year-old male complains of a painful and swollen right calf. The possibility...

    Incorrect

    • A 40-year-old male complains of a painful and swollen right calf. The possibility of deep vein thrombosis (DVT) is being considered. What tests should be conducted to confirm the diagnosis?

      Your Answer:

      Correct Answer: Dopplers of the leg veins

      Explanation:

      Diagnostic Methods for Deep Vein Thrombosis

      When it comes to diagnosing deep vein thrombosis (DVT), there are several methods available. The most common ones are Doppler studies and venography. Doppler studies use B mode ultrasonography to examine the venous system, while venography involves injecting a contrast dye into the veins and taking X-rays. CT scans are not typically used for DVT diagnosis because they require contrast and expose the patient to radiation. D-Dimer concentrations can help rule out DVT if they are negative, but they cannot diagnose it. MRI scans are useful for examining soft tissues and bones, but they are not the best option for visualizing the vasculature. Finally, oxygen saturation of the limbs is not a reliable diagnostic method because tissue perfusion can be the same even if there is arterial disease. Overall, Doppler studies and venography are the most effective methods for diagnosing DVT.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 24 - What could be a potential cause of metabolic acidosis? ...

    Incorrect

    • What could be a potential cause of metabolic acidosis?

      Your Answer:

      Correct Answer: Poorly controlled diabetes

      Explanation:

      Acid-Base Imbalances in Different Medical Conditions

      Poorly controlled diabetes can cause the breakdown of fatty acids, leading to the production of ketones as an alternative energy source. However, an excess of ketones can result in metabolic acidosis due to their acidic nature. On the other hand, chronic obstructive pulmonary disease (COPD) and suffocation can cause the retention of carbon dioxide, leading to respiratory acidosis. In COPD, there may be a compensatory metabolic alkalosis. Voluntary hyperventilation can cause respiratory alkalosis due to the reduction of carbon dioxide. Vomiting can also lead to metabolic alkalosis. Diabetic ketoacidosis is a complication of type 1 diabetes that results in high blood sugar levels, ketone production, and acidosis.

      In summary, different medical conditions can cause acid-base imbalances in the body. It is important to identify the underlying cause of the imbalance to provide appropriate treatment.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 25 - A man in his forties comes in with chest pain resembling a heart...

    Incorrect

    • A man in his forties comes in with chest pain resembling a heart attack and is diagnosed with a myocardial infarction. During his hospitalization, it is discovered that he has familial hypercholesterolemia but his triglyceride levels are normal. What is the underlying biochemical abnormality?

      Your Answer:

      Correct Answer: Defective LDL receptors

      Explanation:

      Lipid Metabolism and Transport in the Body

      The breakdown of triglycerides in the small intestine is facilitated by pancreatic lipase. These triglycerides are then transported to the liver and other parts of the body through chylomicrons.

      Very low-density lipoprotein (VLDL) is responsible for carrying triglycerides from the liver to peripheral tissues. When there is an overproduction of VLDL in the liver, it can lead to high levels of triglycerides in the body.

      Pure hypercholesterolaemia is a condition that arises due to a defect in the process of cholesterol uptake into cells. This process relies on apolipoprotein B-100 binding to LDL receptors and facilitating endocytosis. When this process is disrupted, it can lead to high levels of cholesterol in the body.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 26 - What role does vitamin K play in the body? ...

    Incorrect

    • What role does vitamin K play in the body?

      Your Answer:

      Correct Answer: Activation of clotting factors II, VII, IX, X

      Explanation:

      The Roles of Vitamin K in the Body

      Vitamin K plays several important roles in the body. One of its main functions is to modify clotting factors II, VII, IX, and X through a process called carboxylation. This modification allows calcium to bind to the factors, which is necessary for them to participate in the clotting pathway. This principle is used in full blood counts to prevent clotting by adding EDTA, which chelates the calcium. Vitamin K also modifies osteocalcin and matrix proteins in bone, as well as nephrocalcin in the kidney, in a similar way.

      In addition to its role in blood clotting and bone health, vitamin K is also important for nervous tissue development and growth. However, vitamin K antagonists such as warfarin are sometimes used as anticoagulants to prevent blood clots. It is important to follow guidelines and instructions carefully when using these medications. Overall, vitamin K plays a crucial role in maintaining the health and function of various systems in the body.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 27 - A couple in their early 30s come to your clinic seeking advice. The...

    Incorrect

    • A couple in their early 30s come to your clinic seeking advice. The husband has a history of haemophilia B and they are worried about the possibility of passing it on to their children. Can you determine which of their offspring will be affected by the disease?

      Your Answer:

      Correct Answer: All daughters will be carriers; no sons will be affected

      Explanation:

      The inheritance of Haemophilia A and B is crucial in identifying individuals who are at risk of developing the condition. Haemophilia A and B are genetic disorders that are inherited in an X-linked recessive manner. Haemophilia A is caused by a deficiency in clotting factor VIII, while haemophilia B is caused by a deficiency in clotting factor IX.

      On the other hand, haemophilia C, which is caused by a deficiency in clotting factor XI, is primarily inherited in an autosomal recessive manner. In X-linked recessive conditions like haemophilia B, males are more likely to be affected than females. This is because males only need one abnormal copy of the gene, which is carried on the X chromosome, to be affected.

      Females, on the other hand, can be carriers of the condition if they carry one normal and one abnormal copy of the gene. While carriers can have clotting abnormalities, these are usually milder than those seen in affected individuals. Men cannot pass the condition to their sons, but they will pass on the abnormal X chromosome to all their daughters, who will be carriers.

      Female carriers can pass on the condition to around half their sons, and half their daughters will be carriers. Females can only be affected if they are the offspring of an affected male and a carrier female. In summary, the inheritance of haemophilia A and B is crucial in identifying individuals who are at risk of developing the condition. It also helps in providing appropriate genetic counseling and management for affected individuals and their families.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 28 - What is the primary role of the nucleus in a eukaryotic cell? ...

    Incorrect

    • What is the primary role of the nucleus in a eukaryotic cell?

      Your Answer:

      Correct Answer: To regulate gene transcription and translation

      Explanation:

      The Nucleus: Control Centre of the Cell

      The nucleus is the control centre of the cell, responsible for regulating gene transcription from DNA into mRNA and from mRNA into peptide/protein synthesis. Eukaryotic cells have a membrane-enclosed organised nucleus, while prokaryotic cells lack this structure. The nuclear structure consists of an outer and inner nuclear membrane that form the nuclear envelope, which has nuclear pores allowing the movement of water-soluble molecules. Inside the nucleus is the nucleoplasm containing the nuclear lamina, a dense fibrillar network that acts as a skeleton and regulates DNA replication and cell division. The nucleus also contains nucleoli, structures involved in the formation of ribosomes responsible for mRNA translation.

      Although the incorrect answer options above describe processes in which the nucleus is involved, none of them constitutes its main function within the cell.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 29 - What stage of cellular respiration is responsible for the production of pyruvic acid?...

    Incorrect

    • What stage of cellular respiration is responsible for the production of pyruvic acid?

      Your Answer:

      Correct Answer: Glycolysis

      Explanation:

      The Versatility of Pyruvic Acid in Cellular Metabolism

      Pyruvic acid is a simple alpha-keto acid that plays a crucial role in several metabolic pathways within the cell. It serves as a central intersection where different pathways converge and diverge. One of the primary ways pyruvic acid is produced is through glycolysis, where glucose is broken down into pyruvic acid. Depending on the cell’s needs, pyruvic acid can be converted back into glucose through gluconeogenesis or used to synthesize fatty acids through the acetyl-CoA pathway. Additionally, pyruvic acid can be used to produce the amino acid alanine.

      Pyruvic acid is also involved in respiration, where it enters the Krebs cycle under aerobic conditions. This cycle produces energy in the form of ATP, which is used by the cell for various functions. Under anaerobic conditions, pyruvic acid can ferment into lactic acid, which is used by some organisms as a source of energy.

      In summary, pyruvic acid is a versatile molecule that plays a critical role in cellular metabolism. Its ability to be converted into different molecules depending on the cell’s needs makes it an essential component of many metabolic pathways.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds
  • Question 30 - What are the vitamins that are soluble in fat? ...

    Incorrect

    • What are the vitamins that are soluble in fat?

      Your Answer:

      Correct Answer: Vitamins A, D, E and K

      Explanation:

      Absorption of Fat-Soluble Vitamins

      Fat-soluble vitamins, namely A, D, E, and K, have a different absorption process compared to water-soluble vitamins. In the gut, these vitamins are combined with other fat-soluble substances such as monoacylglycerols and cholesterol to form micelles. These micelles are then transported to the lymphatic system and eventually enter the bloodstream through the subclavian vein.

      However, any issues that affect the absorption of fats will also impact the absorption of fat-soluble vitamins. This means that individuals with conditions that affect fat absorption, such as cystic fibrosis or celiac disease, may have difficulty absorbing these vitamins. It is important to ensure adequate intake of fat-soluble vitamins through a balanced diet or supplements to prevent deficiencies and associated health problems.

    • This question is part of the following fields:

      • Basic Sciences
      0
      Seconds

SESSION STATS - PERFORMANCE PER SPECIALTY

Basic Sciences (2/3) 67%
Passmed