Question

1. As you are sitting at your desk, you look out your window and notice a new species of animal. You remember reading about this new species Covidicus whoknowswhatitis on social media and that people don’t know much about it yet. So, like a good student you go outside to take a closer look. You see that there are lots of individuals of this species and they range in size from about 1g to 1000g. They are transparent and so you can see their internal organs (and you have superpowers, so you know the weight of everything you look at!). You notice that one individual is 10g and has a 1g liver, you then notice another individual that is 30g and has a 3 g liver. In this species, does liver size scale allometrically or isometrically? Both animals turn around and now you see their kidneys. In the 10g species the kidney is 0.5g (yes, they have big kidneys) and in the 30g species the kidney is 1g. In this species, does the kidney scale allometrically or isometrically? Explain the difference between allometric and isometric scaling. Why do many physiological processes or anatomical structures scale allometrically?

Answer 1

In the case of liver ,the liver scales isometrically. It is because ,the size of body and liver has a proportion in the two individuals.

In the case of kidney, it scales allometrically. The ratio of body mass and kidney mass is not proportional in both individuals.This scaling is used to predict metabolic rate, survival probability etc.The equation for allometric scaling is

Y=aM raised to b.

Y is a biological variable. M is body mass.b is scaling component.  

In isometric scaling , the growth of body and it's part are at a constant rate.In allometric scaling the growth of body and it's organs are not proportionate.

Many physiological processes and anatomical structures scale allometrically because each species of organism differs in their geometry and activities. In flying species body mass is not similar to others.