Astudent was visiting a friend at her home. her friend owned two cats. after playing with the cats for
a while, the student began to sneeze. her nose began to run and her eyes became red, watery, and
itchy. it also became hard for her to breathe. a few minutes after leaving her friend’s home, the
symptoms disappeared.
provide a biological explanation for the symptoms the girl developed at her friend’s house. in your
response, be sure to:
• state one reason why her symptoms are not likely due to an infectious agent

This girl is allergic to cat´s hair.

Explanation:

The substance that provokes allergy to cats is a protein produced in the sebaceous glands and that can be found in the cats´ hair. It can be found in clothes, walls, beds, among other places. As it can also be suspended in air, a person can easily breathe it.  In a house with cats, these proteins are present in important amounts.

An allergic reaction is an abnormal response of the immunity system to a substance considered strange to the body, in this case, the protein or the cat´s hair.  These strange substances are called allergens.

The allergen gets in contact with the body for the first time in a sensibilization face. The immunity system considers that this is a strange dangerous substance for the body. In this first stage, the subject submitted to the presence of the allergen does not show any symptoms. But in a second contact, the organism reacts with allergic reactions.

There might appear symptoms in ayes and nose as irritations, stinging, cough, skin´s eruptions and difficulty to breath.

phylogenetic tree is the tree of life or evolution tree. it shows the different branches of evolution. the sequence goes like tissues - coelom - backbone - endoskeleton - segmentation

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.