The two postures of ergonomics that place a person at risk for injuries are :
a) Static Postures – In a static posture a physical exertion is felt as the body remains in the same state or posture for a long period of time. These exertions cause the load to increase and puts force on muscles thereby causing straining and fatigue
b) Awkward Postures – In this the normal postures are not followed and the body is diverted towards a position where muscle efficiency reduces and thus more load/efforts are put in to complete the task.
Something that isn't a major concern could be the wether because the whether usually does not effect his experimental concept. In this case his concept is testing the effects of peanut butter on short term memory
A change in the DNA sequence of a gene leads to a change in the nucleotide sequence in the messenger RNA, which can lead to a change in the amino acid sequence of the resulting protein.