PAG Questions and Answers | Latest Update | 2024/2025 | Already Graded A

PAG Questions and Answers | Latest Update | 2024/2025 | Already Graded A **What is the purpose of mitosis for a living organism?** Mitosis serves the purposes of growth, repair of tissues, and asexual reproduction. **What distinguishes each stage of mitosis?** Prophase: Chromosomes become visible and condense. Metaphase: Chromosomes align in the center of the cell. Anaphase: Chromatids separate and move towards opposite poles. Telophase: Two new nuclei form and the cell splits. **Why is it incorrect to say that cells in interphase are "resting"?** Interphase is not a resting phase because it involves activities such as checking DNA for errors, protein synthesis, mRNA synthesis, and cellular respiration. **What are the functions of various cell types mentioned?** Thrombocytes: Blood clotting. Lymphocytes: Specific immunity. Neutrophils: Non-specific immunity (phagocytosis). Eosinophils: Response to inflammation and parasites. Basophils: Initiating inflammatory responses. **Why are bronchioles and capillaries so numerous?** Bronchioles ensure effective air ventilation to alveoli, while capillaries ensure effective blood perfusion to all alveoli. **Name the sequence of blood vessels, organs, and heart chambers blood passes through from kidney to heart and back to kidney.** Renal vein -> Vena cava -> Right atrium -> Right ventricle -> Pulmonary artery -> Lungs - > Pulmonary vein -> Left atrium -> Left ventricle -> Aorta -> Renal artery. **What is the function of atrioventricular valves?** Atrioventricular valves separate atria from ventricles and prevent blood from flowing back into the atria during ventricular contraction (systole). **Describe the role of coronary arteries and the consequences of blockage.** Coronary arteries supply oxygen and nutrients to cardiac muscle. Blockage can lead to lack of oxygen delivery, causing cardiac muscle death and potentially cardiac arrest. **Why are stains useful in microscopy?** Stains enhance visibility of transparent structures and differentiate cell components and structures based on differential staining methods. **Name the bones and muscles of the human arm and describe the function of each muscle.** Upper arm bone: Humerus. Lower arm bones: Radius and ulna. Biceps: Contracts to bend the arm. Triceps: Contracts to straighten the arm. **Why would a climax community like oak woodland have high species diversity?** Oak woodlands offer varied habitats and food sources, supporting numerous species and complex food webs. **How does farming impact species diversity?** Farming reduces diversity by monoculture practices, habitat loss, and pesticide use, which diminishes habitats for other species.