Rickettisias are now considered as bacteria because they have the characteristics of been spread by arthropods vectors, the cells are extremely small and can be rod shaped or coccoid and they have typical bacterial cell walls. They have no flagella, they are gram negative and multiply by mean of binary fission only in their hosts cells.
Answer:
hydrogen bonds , a helix , b pleated sheet
Explanation:
Answer: They help control what enters and leaves the cell.
Explanation: carbohydrates also help the immune system identify if the cell is foreign or not.
