The word Gymnosperm is formed from the Greek word Gymnos meaning naked or exposed and sperm meaning seed. The word gymnosperm means gymnosperm. Those plants that have flowers, seeds and fruits do not produce because the flower does not have an ovary, so the seeds are naked or expressed are called gymnosperms. The group of vascular plants that produce seeds is called Spermatophyta or green plants. Spermatophyta are divided into two subgroups. Gymnosperms and gymnosperms. All living gymnosperms are called living fossils. Gymnosperms were formerly called flowering plants, but are not today. Because the sporophylls of gymnosperms and the flowers of flowering plants have nothing in common.

Animals that excrete ammonia as excreta are called ammonotelic animals. For example – hydra, earthworms and some fish.

When the concentration of hydrogen ions in the body is low, it is called alkalosis. Alkalosis results in severe convulsions and death.

When the concentration of hydrogen ions in the body is high, it is called acidosis. In acidosis, people become unconscious and may die.

Different types of chemicals that prevent the change of fluid in the body are called buffers. Blood buffers are NaHCO3, Na2HPO4, KHCO3 etc.

If the acid level increases in the blood, the concentration of ions increases. Meanwhile, a Na+ ion enters the blood in exchange for an H+ ion. This results in a decrease in the concentration of H+ ions in the plasma and a change in the pH value of the blood. Again, when the blood alkalinization level increases, the rate of exchange of H+ and Na+ ions between the blood and the glomerular filtrate decreases and the blood pH changes.

When blood pH value (acidity) decreases, NH4+ is produced by the reaction of NH3 and hydrogen ion (H+) in plasma and renal tubule cells. This results in a decrease in the concentration of H+ ions in the plasma and a change in the pH value of the blood. Again, increasing alkalinity has the opposite reaction.

Chemicals that prevent the pH of a solution from changing are called buffers. Blood buffers are NaHCO3, Na2HPO4, KHCO3 etc. Nephron tubular cells reabsorb ions such as Na+, K+, HC3-, PO43- etc. from the glomerular filtrate into the blood. These ions participate in the formation of buffers in the blood and prevent changes in blood pH.
Na+ + HCO3- → NaHCO3
2Na+ + HPO43- → Na2HPO4
K+ + HCO3- → KHCO3

1. Buffer method: Chemicals that prevent the pH of a solution from changing are called buffers. Blood buffers are NaHCO3, Na2HPO4, KHCO3 etc. Nephron tubular cells reabsorb ions such as Na+, K+, HC3-, PO43- etc. from the glomerular filtrate into the blood. These ions participate in the formation of buffers in the blood and prevent changes in blood pH.
Na+ + HCO3- → NaHCO3
2Na+ + HPO43- → Na2HPO4
K+ + HCO3- → KHCO3
2. Ammonia method: When blood pH value (acidity) decreases, NH4+ is produced by the reaction of NH3 and hydrogen ion (H+) in plasma and renal tubule cells. This results in a decrease in the concentration of H+ ions in the plasma and a change in the pH value of the blood. Again, increasing alkalinity has the opposite reaction.
3. Iron exchange method: If the acid level increases in the blood, the concentration of ions increases. Meanwhile, a Na+ ion enters the blood in exchange for an H+ ion. This results in a decrease in the concentration of H+ ions in the plasma and a change in the pH value of the blood. Again, when the blood alkalinization level increases, the rate of exchange of H+ and Na+ ions between the blood and the glomerular filtrate decreases and the blood pH changes.

pH is a measure of hydrogen ion (H+) concentration. A measure of the concentration of hydrogen ions (H+) in a solution is called the pH of the solution. The neutral pH value of the body is 7.0. Body fluids are acidic if the pH value is less than 7.0 and alkaline if it is higher. The ideal blood pH value is 7.4. A pH value below or above 7.4 can cause death in humans.
Buffer solutions can resist pH value changes.