The beginning of the Cambrian Period is marked by the evolution of hard body parts such as calcium carbonate shells. ... These body parts fossilize more easily than soft tissues, and thus the fossil record becomes much more complete after their appearance.
Answer:
the answer is a. any ciliated cell in lungs catches bacteria & debris from lungs causing cough, difficulty breathing, etc.
can develop into asthma, infection of pleura, and bronchitis...
Answer:
Polygenetic inheritance
Explanation
Polygenetic inheritance also called Multifactorial inheritance it occurs when a single characteristic is controlled by more than two genes .
An example is the human skin pigmentation which is determined by the amount of melanin it contains.
Melanin production involves at least four genes. A combination of of melanin producing allele determines the degree of pigmentation.
This shows each gene has exerted a small addictive effect in determining the trait.
Nucleic Acid which is composed of sugar,phosphate backbones, and it has nitrogenous bases