Human Physiology and Anatomy

Glucagon's role in the body is to prevent blood glucose levels dropping too low. It acts on the liver and stimulates the conversion of stored glycogen (stored in the liver) to glucose, which can be released into the bloodstream. This process is called as glycogenolysis.

Cytokinin hormone does the major function of checking senescence and mobilising solutes from one part to another. It promotes the cell division or cytokinesis, in plant roots and shoots.

• The function of fungal part of a lichen is the absorption of water and minerals from the substratum and providing protection for the phycobiont.
• Food production is done by phycobiont.
• So, the correct answer is 'Absorption of minerals and Protection'.

The vacuole are the membranous vesicular structures in the cells of the living organisms. The vacuoles are involved in the storage of the food materials. The presence of vacuole provides rigidity and shape to the cell with the help of turbulence. The wastes from the cells can be excreted with the help and movement of the vacuoles. The vacuoles are not responsible for locomotion. 

Vacuoles are storage bubbles found mostly in plant cells. These are used for storage of food or water. The vacuolar membrane is a single layered and is called as tonoplast. Osmotic pressure and turgidity is maintained by vacuoles. They store toxic metabolic by-products or end products of plant cells. Such vacuoles are thrown out of the cell by exocytosis. Thus, the correct answer is option D.

• The function and significance of vacuoles vary greatly according to the type of cell in which they are present.
• In general, the functions of the vacuole include- Isolating materials that might be harmful or a threat to the cell. Containing waste products. 
• Containing water in plant cells. Maintaining internal hydrostatic pressure or turgor within the cell. Maintaining an acidic internal pH. 
• Allows plants to support structures such as leaves and flowers due to the pressure of the central vacuole etc.
  
  Therefore, the correct answer is option D.

The contractile vacuoles are the structures which are present in the cells of the lower organisms. The vacuole plays an important role in excretion and osmoregulation. The wastes like the ammonia can be excreted through the vacuoles. The water and the other salts are also removed through this vacuoles in order to maintain the osmotic balance. 

Kupffer cells are specialized macrophages located in the liver sinusoids that perform phagocytosis to remove debris and pathogens.

Liver is the largest gland of the body weighing about 1.2 to 1.5 kg in an adult human. It is situated in the abdominal cavity, just below the diaphragm and has two lobes. The hepatic lobules are the structural and functional units of liver containing hepatic cells arranged in the form of cords. Each lobule is covered by a thin connective tissue sheath called the Glissons capsule. The bile secreted by the hepatic cells passes through the hepatic ducts and is stored and concentrated in a thin muscular sac called the gall bladder. The duct of gall bladder (cystic duct) along with the hepatic duct from the liver forms the common bile duct. The bile, pancreatic juice and the intestinal juice are the secretions released into the small intestine. The bile released into the duodenum contains bile pigments (bilirubin and biliverdin), bile salts, cholesterol and phospholipids but no enzymes. Bile helps in emulsification of fats, i.e., breaking down of the fats into very small micelles. Bile also activates lipases. Fats are broken down by lipases with the help of bile into di-and monoglycerides.

Hepatocytes are metabolic superachievers in the body. They play critical roles in synthesizing molecules that are utilized elsewhere to support homeostasis, in converting molecules of one type to another and in regulating energy balances. Excess glucose entering the blood after a meal is rapidly taken up by the liver and sequestered as the large polymer, glycogen (a process called glycogenesis). Later, when blood concentrations of glucose begin to decline, the liver activates other pathways which lead to depolymerization of glycogen (glycogenolysis) and export of glucose back into the blood for transport to all other tissues. Excretion, digestion and histolysis are not the functions of liver. Thus, option D is correct.

Liver is the largest gland of the body. It plays a prominent role in the metabolism of carbohydrates, proteins, fats. It converts excess of glucose into glycogen and thus regulates sugar level in blood. It plays a major role in the breakdown of hemologbin. Thus option D is the correct answer. 

Glycogenolysis is the process by which glycogen stored in the liver and muscle cells of animals, is broken down into glucose to provide immediate energy and to maintain blood glucose levels during fasting. Glycogenolysis occurs in the liver and is stimulated by the hormones glucagon and epinephrine (adrenaline). It is the catabolic process where break down of glycogen occurs by the enzyme glycogen phosphorylase.

The liver stores glycogen but does NOT release glycogen into blood. Instead, it performs glycogenolysis to break down glycogen and releases glucose into blood. All other options ARE liver functions: bile production, bilirubin uptake/excretion, and urea synthesis.