In human beings, the respiratory pigment that carries oxygen is ______.
haemoglobin
Haemoglobin is an iron-containing protein present inside red blood cells (erythrocytes). Each haemoglobin molecule has four haem groups, and each haem holds one Fe2+ ion that reversibly binds one O2 molecule.
In the lungs, where oxygen partial pressure is high, haemoglobin picks up oxygen to form oxyhaemoglobin; at the tissues, where oxygen is low and CO2 is high, it releases oxygen for cellular respiration.
Insulin is a pancreatic hormone that regulates blood glucose, myosin is a contractile protein in muscle fibres, and chlorophyll is the green photosynthetic pigment found in plants - none of them transports oxygen in humans.
Hence, the respiratory pigment that carries oxygen in human beings is haemoglobin.
Which part of the human eye controls the amount of light entering the eye?
Why is the small intestine able to fit into a compact space within the human body?
Why does the sight of or thought of delicious food make our mouths "water"?
Which acid does our stomach produce and what is its pH?
Which defect occurs when the eye lens loses its ability to focus on near objects due to decreased flexibility?
Which gas is essential for aerobic respiration in animals?
Match 'Column A' with 'Column B' in context of the muscular layers in blood vessels.
| Column A | Column B |
| (a) Thick tunica media | (i) Vein |
| (b) Smallest vessel diameter | (ii) Artery |
| (c) Large lumen | (iii) Capillary |
| (d) Endothelium | (iv) All blood vessels |
A researcher needs to deliver a drug directly to the cells of an organ for rapid effect. Which blood vessel should the delivery target for optimal diffusion to surrounding cells?
What is the main function of saliva in the mouth during digestion?
Which of the following structures in throat is responsible for the prevention of collapse of air-passage in human beings?
A resting person, usually has a pulse rate between ______ and ______ beats per minute
In humans, neck and head are joined by which joint ?
The human skeleton is composed of around ______ bones at birth.
Identify the disease that is not caused by virus.
Which one of the changes observed during adolescence is not associated with boys?