Question
Question: Which pigment helps some nocturnal animals to see at night? A. Haemoglobin B. Porphyrin C. Gua...
Which pigment helps some nocturnal animals to see at night?
A. Haemoglobin
B. Porphyrin
C. Guanine
D. Heparin
Solution
The word nocturnal animals refers to the animals which are active during the night and sleep during the daytime. These nocturnal animals have some specialized sensory cells which help them to hear, smell, and most importantly for sight.
Complete answer: Guanine is a nucleobase that is found in the genetic acids that are DNA and RNA. Guanine is derived from purine. Guanine consists of a ring system with conjugated double bonds in which pyrimidine- imidazole are fused. Guanine compound is white in color and is found in the epithelium or retinal cells of nocturnal animals. The tapetum lucidum is a mirror-like surface that reflects the light towards the outside and hence allows absorption of light by guanine pigment even at night at a very low intensity of light.
-Haemoglobin is a protein that is found in the erythrocytes (RBC) of blood. Hemoglobin is an iron-containing protein that helps in oxygen transport in the cells. The oxygen from the lungs or gills is carried by the hemoglobin to all parts of the body. The release of oxygen in the cell leads to aerobic respiration which provides energy for the metabolic activities of the body.
-Porphyrin is composed of four pyrrole subunits which are interconnected at their alpha carbon atoms through the methine bridges. Porphyrin is an organic compound that is formed by groups of heterocyclic macrocycles. Porphyrin is used as a biomarker in toxicology studies.
-Heparin is a protein produced by the human body which acts like a thinner and prevents the clotting of blood. It is an anticoagulant.
So, option C is the correct option.
Note: Crystalline guanine was extracted from scales of fish Alburnus alburnus in Paris in 1656 by Mr. Jaquin. It is called a pear essence. It is used in the cosmetic industry and also in metallic paints. Crystalline guanine in nail polish and produces shimmering luster. Japanese nightingales use guanine as a facial treatment.