Answer:
The answer is option A: layers
Amino acids. Every protein is a long chain of amino acids.
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.
This definition above refers to the geographic isolation.
It means exactly what it says in the definition - one species is left behind from the rest of the population, and it stays in that particular location, evolving and changing from the species and population it was once a part of.
Answer:
ok
Explanation:
Simple sentences contains on independent clauses ,also called main clause ,that stands alone.
Complex sentences contains an independent clauses plus one or more dependent clause.
Compound Sentences contains two independent clauses joined with the coordinating conjugation and comma .AND IT'S ENGLISH QUESTION NOT OF BIOLOGY.