Self-study
Lathyrism, a debilitating neurological disorder caused by the consumption of the legume Lathyrus sativus, is widespread among the domestic animals of some countries. ████████ ██ ███ ████ ██ █████ █████████ ████ █████████ ███████ ████ ████ ████████ ████████ ███████ ███ ███ ███████ ███ ████████ ██████████ ████ ███ █████████
Summary
The stimulus says that eating Lathyrus sativus (L.S.) can cause domestic animals to develop a severe disorder called lathyrism. However, researchers have failed to use rats to study lathyrism. This is because rats that ate L.S. didn’t develop lathyrism symptoms.
Strongly Supported Conclusions
These conclusions are strongly supported:
Not all animals that eat L.S. will develop lathyrism.
Rats are less vulnerable to lathyrism than at least some other animals.
19.
Which one of the following ██ ████ ████████ █████████ ██ ███ ███████████ ██████
a
The physiology of ████ ██ █████████ █████████ ████ ████ ██ ████████ ████████
This is not supported. The stimulus doesn’t offer any general facts about the physiology of rats versus domestic animals. We don’t even know why rats don’t develop lathyrism, let alone if it’s due to a “radical” difference in physiology.
b
The rats did ███ ███████ ██ ████ ████████ ███████ ██ ███ ███ ████████ ███████ ████ ██████████ ██████████
This is not supported. Nothing in the facts suggests how much L.S. is needed to cause lathyrism in domestic animals, how much the affected domestic animals actually eat, nor how much was given to the rats.
c
Not all animal ███████ ███ ███████ ███████████ ██ ██████████
This is strongly supported. The stimulus says that rats don’t develop lathyrism from eating L.S., even though lathyrism is widespread in some domestic animal species. This lets us infer that different species of animals have different susceptibility to lathyrism.
d
Most of the ███████ ████ ███ ████████ █████████ ███ █████████
This is not supported. The stimulus mentions that lathyrism occurs in some domestic animals, but doesn’t indicate whether or not it can occur in non-domestic animals. Because we don’t know anything about non-domestic animals, we can’t compare.
e
Laboratory conditions are ███ █████████ ██ ███ ███████████ ██ ██████████
This is not supported. The facts strongly imply that the problem with these lathyrism studies is that rats don’t develop lathyrism; nothing suggests that the laboratory conditions themselves are to blame. We don’t even know for sure if the studies happen in a laboratory!