From an evolutionary perspective, phobias are a result of learning, which suggests that humans and other animals that rapidly learn to fear certain threatening objects or situations would have a selective advantage over other members of the species.

Phobia is a result of associative learning that suggests human and other animals to learn fear in certain threatening objects or situations.

Explanation:

Phobia is a psychological condition that defines any kind of fear which will appear from certain type of objects and it scares intensely.

Several learning experiences creates fear when the particular person is expose to that condition.

These include some associative learning that is related with behavior.

This type of learning is usually based on stimuli which is generated through positive or negative consequences.

This type of learning which create phobia contain classical conditioning, Operant Conditioning, Cognitive social conditioning etc.

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides