HIV/AIDS can be categorized as a new or emerging infectious disease. By putting it into this category, we are effectively saying that
A. this infection hasn't been observed in the human population prior to recent (approximately 50 years or sooner) outbreaks.
B. this disease has been in susceptible populations for centuries, but has only recently achieved infection levels that became detectable.
C. the infectious agent is still evolving and changing, unlike with older, more established diseases such as plague or polio.
D. the disease has always been in susceptible populations and causing disease, but we lacked the technology to detect it.
A
You might also like to view...
Within the human genome, 45% of the DNA is composed of what?
A. transposable elements B. highly repetitive DNA C. moderately repetitive DNA D. coding sequences E. noncoding sequences
Which of the following is a reversible post-translational covalent modification?
A. phosphorylation B. acetylation C. disulfide bond formation D. phosphorylation and acetylation E. acetylation and disulfide bond formation
Dmitri Ivanovski demonstrated that TMV was not spread via bacteria by
A. transmitting sap of infected plants from generation to generation. B. filtering sap from an infected plant through pores smaller than bacteria, and then applying it to a healthy plant. C. spraying sap from an infected plant onto a healthy plant. D. sterilizing sap from an infected plant and then applying it to a healthy plant. E. treating an infected plant with a broad spectrum of antibiotics before extracting sap.
The female gametophyte is the
a. flower. b. ovule. c. embryo sac. d. carpel. e. ovary.