Question

smaller the animal more is the rate of respiration WHY?

Answer 1

Larger the organism…more is the distance covered for circulation of blood inside the body…so, more time is taken to circulate blood to each and every part of the body…..which will further affect the heart beat and also lower the breathing rate …so breathing will be deep, but it's rate is slow incase of huge animals like a whale.

But, incase of smaller organisms, the blood circulation is faster due to smaller body eg. a Shrew or a Rat, since distance to be travelled by circulating blood will be very less…so, breathing rate will be faster here.

If all animals need the same concentration of oxygen throughout their tissues, larger animals need more O2 because of their more tissue, but metabolism is probably more important than size alone. One thing to consider isn't so much the amount of oxygen but the diffusion of oxygen. Large animals have trouble getting oxygen to all of their tissues, so they have lungs, hemoglobin, and efficient circulatory systems to move the oxygen in and CO2 out. Small animals have less tissue to diffuse through, so they can rely more on simple diffusion of atmospheric oxygen through their bodies.

I hope you understood the concept.

Answer 2

no smaller animals will required less amount of oxygen and they also give small amount of carbon dioxide but when the animal is big then it will take more oxygen and relase more Co2