Answer
Commensal bacteria stimulate the immune system of the host to enhance defense mechanisms that block pathogen entrance and colonization. Moreover, by creating antimicrobial properties and signals & fighting with other bacteria for food and attachment sites, such bacteria might effectively limit the spread of respiratory infections. In healthy animals, the majority of commensal bacteria live inside the intestine's lumen, although some are also found in immediate contact with the intestinal epithelium. New studies have shown that commensal bacteria may live in stable stomach lymphoid tissues. But every once in a while, especially when they travel to other areas and leave their natural habitat, these commensal bacteria might cause illness. In both old and very and also in young persons, it can spread throughout the rest of the body, causing pneumonia, infection, and meningitis.
You can learn more about commensal bacterium from the following link:
brainly.com/question/28474277
#SPJ4
Sperm cells inside the pollen grain travel down the pollen tube and into the ovary which contains the ovules. Fertilization occurs when one of the sperm cells fuses with the egg inside of an ovule
White blood cells increase as they are the cells that destroy pathogens
The main function of the Krebs cycle is to generate energy for the cell. The Krebs cycle is also known as the citric acid cycle and is part of cellular respiration. Cellular respiration is a series of chemical reactions that cells use to break up sugars into a form that the cell can use. Cell respiration requires oxygen to take place. Cellular respiration consists of four stages:1. the breaking down of glucose into molecules (glycolysis)2. the link reaction - this process forms a link between glycolysis and the Krebbs reaction3. Krebbs reaction 4. The electron transport chain
A force that creates something MUST be constructive force so the answer will be B.