Question

1. How is CO2 transported in the blood? (pick one)

a. Most of it binds to hemoglobin alongside with oxygen

b. It competes with oxygen for the biding site with hemoglobin.

c. It forms calcium carbonate CaCO3 increasing the pH of the blood (more basic)

d. It dissolves as bicarbonate ion H2CO3 decreasing the pH of the blood (more acidic)

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2. Which of the following describes a closed circulatory system?

a. Nutrients diffuse from gastrovascular cavity into the tissues and waste diffuses in the opposite direction.

b. Nutrients and waste diffuse in and from the pseudocoelm

c. Hemolymph moves from the heart into the tissues and cavities and then drains back into the main cavity.

d. Blood moves from the heart into arteries and into smaller vessels and then back into larger vessels as it makes its way back to the heart.

Answer 1

1. Most of CO2 is transported by converting it to bicarbonate ions. About 70% of CO2 is carried by converting into bicarbonate. Bicarbonates make the blood more basic, that is increase the pH of blood. The haemoglobin can transport oxygen as well as CO2 by carrying it at the N terminal of haeme protein, but this acvounts for only 23% of transportation. Rest 7% is transported by fissolving in plasma as carbonic acid.

So the correct option is a

2. A closed circulatory system consists of arteries, veins, heart. The blood flows from heart to arteries and into smaller vessels known as capillaries. Then back into larger vessels known as veins to travel back to heart.

An open circulatory system pumps the haemolymph directly into the tussye and cavities and drains back.

So the right answer is d.