Regarding studies with infectious agents in animals, as the bsl and absl number increases from 1 to 4, what happens to the containment and safeguard practices?

Work in BSL-4 containment laboratory requires time and great attention. The same work that is done in a BSL-2 laboratory will take significantly longer in a BSL-4 setting. This increased time requirement is due to a lot of factors that are aimed at protecting the worker from laboratory-acquired infections. The BSL 4 laboratory should contain a Class III biological safety cabinet but may use a Class I or II BSC in combination with a positive-pressure, air-supplied full-body suit. Usually, BSL 4 laboratories are in separate buildings. Exhaust streams are filtered through high-efficiency particulate air (HEPA) filters, depending on the agents used.

the menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.

chert is a sedimentary rock composed of microcrystalline or cryptocrystalline silica. with this little bit of information, you can come to the conclusion that your answer is c.  

explanation: