Aging workers of the Neotropical termite, Neocapritermes taractua, develop blue
ID: 280055 • Letter: A
Question
Aging workers of the Neotropical termite, Neocapritermes taractua, develop blue crystal- containing glands (backpacks") on ther backs. When they fight intruding termites and are hampered, these "blue" termites explode, and the glands spew a stickly liquid Sobotnik et al 2012). The following data are from an experiment that measured the toxicity of the blue substance. A single drop of the liquid extracted from blue termites was placed on individuals of a second termite species Labiotermes labralis, and the number that were immobilized (dead or paralyzed) within 60 minutes was recorded. The frequency of this outcome was compared with a control treatment in which liquid from glands of white" termites lacking teh blue crystals was dropped instead. Liquid Source Unharmed Immobilized Blue Workers Wnite Workers 31 What is the expected number of unharmed blue workers? to whole number) What is the expected number of immobilized blue workers? to whole number) What is the expected number of unharmed white workers? to whole number) What is the expected number of immobilized white workers? to whole number) round to 2 Critical value X0051, cs).05 Ho"The proportion of immobilized individuals is the same between liquid from blue and white workers. We fal to reject, accept) the Ho HA-The proportion of immobilized individuals is not the same. Can we assume this is true? Are the contents of the blue backpacks toxic? ves or no)Explanation / Answer
The expected numbers are calculated by the formula,
(Row total x Column total) / grand total
Expected number of unharmed blue workers,
= (40×34)/80
= 17
Expected number of immobilised blue workers,
= (40×46)/80
= 23
Expected number of unharmed white workers,
= (40×34)/80
= 17
Expected number of immobilised white workers,
= (40×46)/80
= 23
Degree of freedom = (number of rows -1)(number of columns -1)
= (2-1)(2-1)
= (1)(1)
= 1
X2 is the summation of all (O-E)^2/ E
= 40.1023
P value is less than 0.00001
We therefore reject the Null hypothesis
The proportion of immobilised individuals are not the same.
The contents of the blue backpacks are toxic.