NEET Practice Questions (MCQs) with Answers & Solutions

Granular white blood cells (WBCs) are characterized by the presence of granules in their cytoplasm. These include Neutrophils, Eosinophils, and Basophils. Lymphocytes and Monocytes are agranular WBCs.

A thrombus is a blood clot that forms in the circulatory system. It can obstruct blood flow, leading to various medical conditions. The other options do not correctly describe this condition.

The Sinoatrial Node (SAN) initiates the heartbeat, which is true. However, the sympathetic nerve fibers increase cardiac activity, but this does not explain why the SAN initiates the heartbeat. Therefore, both A and R are true, but R is not a correct explanation of A.

Clotting of blood is indeed a characteristic of human blood, making A true. Each erythrocyte possesses hemoglobin (Hb), which is also true. However, the presence of Hb in erythrocytes does not explain why blood clots. Therefore, both A and R are true, but R is not a correct explanation of A.

Respiration is primarily responsible for producing energy within the body. During cellular respiration, glucose and oxygen are converted into energy (in the form of ATP), carbon dioxide, and water. This process is essential for the survival of cells and the functioning of the body.

Respiration that occurs in the presence of oxygen is called aerobic respiration. This process involves the complete oxidation of glucose to carbon dioxide and water, releasing a significant amount of energy. Aerobic respiration is the most efficient method of producing energy in cells and occurs in the mitochondria.

Pulmonary respiration refers to the process of breathing involving the lungs. Among the options given, humans show pulmonary respiration. In humans, the respiratory system includes the lungs where oxygen is taken in and carbon dioxide is expelled.

The trachea is supported by cartilaginous rings that are C-shaped. These C-shaped rings provide structural support to the trachea, preventing it from collapsing while allowing flexibility and movement during breathing and swallowing.

The lung contains many small balloon-like air sacs called alveoli. These alveoli are the sites of gas exchange in the respiratory system. They provide a large surface area for oxygen and carbon dioxide to be exchanged efficiently between the lungs and the bloodstream.

The intake of air is called inhalation. During inhalation, the diaphragm and intercostal muscles contract, causing the chest cavity to expand and air to be drawn into the lungs.