Question

Colourless blood of animal due to

• A. Cu
• B. Fe
• C. Hemoglobin
• D. None of Above

Hint:

The color of blood in animals is usually attributed to the presence of hemoglobin (iron-based) or hemocyanin (copper-based). Hemoglobin gives the characteristic red color to blood in vertebrates.

Answer 1

The Correct Option is D

Colourless blood in animals occurs when the blood lacks red blood cells or hemoglobin, which are responsible for the characteristic red color of blood.

Cu (Copper): In some invertebrates like mollusks, copper-based blood (hemocyanin) is present. Hemocyanin is blue in color when oxygenated, not colorless. So, copper-based blood is not colourless.
Fe (Iron): Iron is a component of hemoglobin in vertebrates, but iron itself is not a reason for blood being colourless. In fact, hemoglobin is red when oxygenated due to the presence of iron.
Hemoglobin: Hemoglobin gives blood its red color when oxygenated. If an animal's blood lacks hemoglobin, it could result in pale or colourless blood, but this is not typical for most animals.
None of Above: This option is correct because colourless blood typically occurs in animals that lack hemoglobin or have a different kind of circulatory fluid like lymph. In certain animals such as some marine invertebrates (e.g., certain mollusks), the absence of red blood cells results in a pale or colorless fluid.

Thus, the correct answer is (D) None of Above.