Distinguish between pests and vectors, give an example of each with cattle, and explain the digestion and absorption of carbohydrates, proteins, and fats in humans.

A pest is an organism that causes direct harm or damage to humans, their crops, or livestock. A vector is an organism that transmits a disease-causing pathogen from one host to another.

• a) Pests of Cattle: Ticks
• b) Vectors of a Cattle disease: Tsetse fly (transmits trypanosomiasis)

• a) Carbohydrates: Glucose (or monosaccharides)
• b) Protein: Amino acids
• c) Fats: Fatty acids and glycerol

The end products of fat digestion, fatty acids and glycerol, are absorbed into the epithelial cells of the small intestine. Inside these cells, they are re-esterified to form triglycerides. These triglycerides are then packaged into chylomicrons, which are released into the lacteals (lymphatic capillaries) within the villi. From the lacteals, they enter the lymphatic system and eventually the bloodstream.