Answer:
The correct answer is - sexual transmission.
Explanation:
HIV infections can be transmitted by the various mode. Sexual transmission is one of the major mode of transmission which is comprise almost 90 % of HIV infection, according to the reports. These are relatively inefficient mode, unprotected or unnatural sex is the major mode for the HIV transmission worldwide. Cases are now comparatively less than when it was discovered due to awareness.
Thus, the correct answer is - sexual transmission.
D bacteria are the main nitrogen transporters
They are involved in a chemical digestion.
Chemical digestion involves breaking down the food into simpler nutrients that can be used by the cells. It begins in the mouth when food mixes with saliva which contains enzyme salivary amylase that breaks down carbohydrates. It also occurs in the stomach where HCl and pepsin forms chyme and small intestine especially in the duodenum.
They make the structure and function of the cell