If the inner lining of the air sacs neither thin nor highly vascularized, then it can be inferred that AIR SACS ARE CANNOT BE THE SITES OF GASEOUS EXCHANGE BETWEEN AIR AND BLOOD. Air sacs are generally lined with mucus and surrounded with blood capillaries.
In case of birds, air sacs play an important role in respiratory system.
Hi there!
Sustainability means that something or someone has the ability to keep something going.
For example, a plant could have good life sustainability because it has a special poison, keeping predators away from it.
You could be self sustainable by growing your own crops, collecting your own water, and making things you need.
Hope this helps!
The general definition of a gene is some heredity that is passed on from a parent to an offspring. Scientifically speaking, the transfer involves a sequence of nucleotides that forms part of the chromosome. This sequence of nucleotides is a DNA.
Thus, the answer would be
A. a segment of DNA
