Approximately seventy percent of carbon­ dioxide absorbed by the blood will be transported to the lungs

Explanation

The correct option is a) as bicarbonate ions.Explanation of each option:A. As bicarbonate ions (Correct Option): Approximately seventy percent of carbon dioxide (CO2) absorbed by the blood is transported in the form of bicarbonate ions (HCO3-). This is the primary method for CO2 transport in the blood. It involves a chemical reaction where CO2 combines with water (H2O) to form carbonic acid (H2CO3), which rapidly dissociates into bicarbonate ions (HCO3-) and hydrogen ions (H+). This bicarbonate ion is then carried in the bloodstream to the lungs for elimination.B. In the form of dissolved gas molecules: Some CO2 (around 7-10%) is transported in the bloodstream as dissolved gas molecules in plasma. However, this is a relatively small fraction compared to the bicarbonate ion transport method.C.By binding to R.B.C (Red Blood Cells): A smaller portion of CO2 (around 20-23%) binds to hemoglobin within red blood cells, forming carbamino compounds. This is a significant but secondary method compared to bicarbonate ion transport.D. As carbamino-hemoglobin: This option refers to the CO2 that binds to hemoglobin within red blood cells. It is a less dominant method of CO2 transport compared to bicarbonate ions.Brief Summary: Approximately seventy percent of carbon dioxide (CO2) absorbed by the blood is transported as bicarbonate ions (HCO3-). This process involves the conversion of CO2 to bicarbonate ions in a chemical reaction and is the primary method for CO2 transport in the bloodstream. While CO2 can also be transported as dissolved gas molecules, by binding to red blood cells, and as carbamino compounds, these are secondary methods in comparison to the predominant bicarbonate ion transport.