The answer is protect the body from infection by pathogens
The physical barrier is made of epithelial cells, mostly will be keratinized to increase their sturdiness further. They will impede the pathogen physically by barricading the cells, makes the pathogen could not invade deeper part of the body. Histamine and antibodies should be the role of immune cells, not epithelial.
A. is the correct answer. Qualitative observation deals with data that can be observed with our senses.
Answer: Ethylene Gas
Explanation: Ethylene Gas Can be Used to Regulate Fruit Ripening Ethylene is a gas and is known as the “fruit-ripening hormone.”
We have a case of adaptability. Natural selection influenced by the environment selected which plant would do the best, In this case, A has adapted better than B.
