Zoology MCQs for NEET — Practice Questions with Answers

The hepatic portal system starts from the digestive system and carries nutrient-rich blood to the liver. This allows the liver to process nutrients, detoxify substances, and regulate blood sugar levels.

The hepatic portal vein is responsible for carrying glucose and other nutrients from the digestive tract to the liver. Here, the liver can process these nutrients and regulate their levels in the blood.

Lymph nodes are small, bean-shaped structures that produce and store cells that help fight infection, including antibodies. Antibodies are proteins produced by B cells that neutralize pathogens such as bacteria and viruses, making them a critical part of the immune response.

The kidney is not considered a major organ of the lymphatic system. The major organs of the lymphatic system include the lymph nodes, thymus, and spleen, which are involved in the production and maturation of lymphocytes and the filtration of lymph.

The spleen is often referred to as the 'graveyard' of RBCs because it is the primary site where old and damaged red blood cells are broken down and removed from the bloodstream. The spleen filters the blood, removing pathogens and old cells, and helps in recycling iron from the hemoglobin.

Mature red blood cells (RBCs) in humans do not have a nucleus and, therefore, lack DNA. This adaptation provides more space for hemoglobin, enabling efficient oxygen transport. In contrast, other cells like spermatozoa, hair roots, and ovum contain DNA.

Veins are blood vessels that carry blood toward the heart from various organs and tissues. This is true for both deoxygenated blood (like in systemic veins) and oxygenated blood (like in pulmonary veins). Thus, the correct statement for all veins is that they transport blood from organs to the heart.

Diastolic pressure is the pressure in the arteries when the heart rests between beats. The normal diastolic pressure for a healthy adult is typically around 80 mmHg.

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.