What is the purpose of using reverse transcriptase?

Zoe decided to measure the hand length of each of her classmates. first she marked a line across each student's wrist and lined up a ruler from this mark to the top of the middle finger to measure the length. then she recorded the measurements in the table below. marla did this the same way for each classmate, and then zoe used this ruler to measure each straight line and record the data below. this data is invalid. what is the most likely reason why it is invalid? the ruler is marked in centimeters, but zoe recorded data in inches. the range of lengths is too wide, so zoe must have misread the ruler. marla’s complicated measuring procedure was overly confusing. marla could have been inconsistent while drawing outlines of fingers.

Which is an advantage of having memory cells when a pathogen is encountered for a second time. a) the memory cells are what proliferate into clones of cells in response to the binding of an antigen. b) memory cells are vital to the primary immune response in that they immediately recognize pathogens even at the first encounter. c) memory cells are essentially effector cells that are short lived and attack antigens even without having a receptor specific to that antigen. d) it ensures that more lymphocytes with a receptor specific to a particular antigen will be present than in a host that had never encountered that pathogen.

Can someone pretty me with this ? it’s urgent.compare the three theories of emotion. here are the three theories of emotion. cannon-bard theory of emotion: the belief that both psychological arousal and emotional experience are produced stimultaneously ( at the same time) by the same nerve stimulus. james-lange theory of emotion: the belief that emotional experience is a reaction to bodily events occurring as a result of an external situation. ( “ i feel sad because i am crying.) schachter-singer theory of emotion: the belief that emotions are jointly determined by a nonspecific kind of psychological (bodily function) arousal and its interpretation, based on environmental ( natural surroundings) cues. which of these theories makes most sense to you? why. your response should be written using proper english spelling and grammar. and it needs to be 10 complete sentences.