Functions of the kidney include: 1. removing waste products from the blood. 2. maintaining fluid and electrolyte balance. 3. secreting substances that affect blood pressure.

1,2,3

Explanation:

1. One of the major function of the kidney is to excrete metabolic waste. When the blood is perfused through the Bowman's capsule, an ultrafiltrate of the blood is produced in the glomerulus, the filtrate in Bowman's capsule contains salt, glucose, amino acids, nitrogenous waste, etc while the cells and proteins are retained in the blood. The waste are excreted as urine or uric acid.

2. One of the function of the renal tubule is to maintain fluid and electrolytes balance. When the glomerulus filtrate is formed, it contains almost all the crystalloids of plasma which includes water, Na+, Cl-, glucose, amino acid and K+. The renal tubule reabsorb water and solute to the blood to maintain water and electrolytes balance.

3. The kidney secrete a hormone Renin, which control other hormones angiotensin and aldosterone that helps to control blood pressure.

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.