A tourist presented to a primary care health clinic complaining of malaise, fever, and headache. She has subsequently been diagnosed with Rocky Mountain spotted fever, a pathology caused by Rickettsiaceae. Which of the followed statements best captures a characteristic trait of Rickettsiaceae?
A. They are eukaryotic.
B. They have both RNA and DNA.
C. They have a distinct spiral-shaped morphology.
D. They are neither gram-negative nor gram-positive

They have both RNA and DNA

Explanation: Rickettsiaceae possess both nucleic acids RNA and DNA, this is a distinctive characteristics of the organism. They are pleomorphic organisms and are mostly gram-negative organisms.

Rickettsiaceae are infectious to arthropods therebygiving making them an intermediate host or carriers and human can be infected via biting from infected arthropods.

Guard cell function

Explaination:

Guard cells are cells surrounding each stoma. They help to regulate the rate of transpiration by opening and closing the stomata. Light is the main trigger for the opening or closing of stomata.