Biology

Leukaemia is a disease characterized by an abnormal and excessive increase in white blood cells (WBCs). This overproduction disrupts normal blood cell function, leading to various health problems. The other options do not involve increased WBCs.

The spleen is known as the 'graveyard of RBCs' because it is the primary organ where old and damaged red blood cells are removed and destroyed.

The ibex is a wild mountain goat species found in the Himalayas and other alpine regions. It is not a dog, hen, or sheep, making 'Goat' the correct answer.

Insulin lowers blood glucose levels by facilitating cellular uptake of glucose, whereas carbohydrates, cholesterol, and epinephrine can raise blood glucose levels. Therefore, insulin is the exception in this list.

The Ishihara test is a widely used color perception test specifically designed to detect red-green color deficiencies. The other options are unrelated to color vision testing.

Thrombosis is the formation of a blood clot inside a blood vessel, which can obstruct the flow of blood. This matches the description of 'clotting of blood vessels.'

Enzymes are biological catalysts that speed up chemical reactions in living organisms. They are primarily made up of proteins, which are chains of amino acids folded into specific shapes necessary for their function.

The pupil of the eye does not grow in size after birth; it changes size temporarily to regulate light entry but its physical size remains constant. Other organs like the kidney and liver grow as the body grows.

Sickle cell anemia is a genetic disorder caused by a mutation in the hemoglobin gene, leading to abnormal red blood cells. It is not caused by viruses, bacteria, or vitamin deficiency.

Fat digestion primarily occurs in the small intestine where bile from the liver emulsifies fats and pancreatic enzymes break them down for absorption.