Your screening results come back from the lab and they are negative for all possible pathogens. you order a second screening immediately. what is one possible reason for certain organisms to be prematurely (and sometimes wrongly) dismissed from pathogen screens when a microbial disease of the skin is suspected?
a. organisms were present in the sample, but died or were broken down before screeningb. the presence of certain organisms may not seem significant because they are part of the normal skin microbiota. c. samples are taken from areas of active infection or inflammation. d. the technology does not exist to positively identify certain pathological organisms.

Bisphenol a (often called bpa) is a chemical found in products that people use every day, from water bottles to food containers to children's toys. unfortunately, bpa leaches out of its many products and makes its way into our bodies. what are the health effects of bpa exposure? ongoing research is finding that elevated exposure to bpa can affect a wide variety of developmental and physiological processes, but one of the first studies of bpa's health effects came about because of a simple mistake in the lab. at a laboratory at case western reserve university in 1998, geneticist patricia hunt was making a routine check of her female lab mice. as she extracted and examined developing eggs from the ovaries, she began to wonder what had gone wrong. she noticed that many of the eggs showed problems with their chromosomes, and some had irregular amounts of genetic material, which can lead to miscarriages and birth defects in mammals. she learned that a lab assistant had mistakenly washed the plastic mouse cages and water bottles with a harsh soap, releasing bpa from the plastic. knowing that bpa is an endocrine disruptor, a chemical that can enter organisms and mimic hormones, hunt set out to discover whether it had adversely affected her mice.

Can ground tissue do photosynthesis

A. describe the scientific method, using pasteur's swan-necked flask experiment as an example.