Naturalist: Different nonhuman primate species exhibit many contrasts in behavior. If a zookeeper leaves a screwdriver within reach of a chimpanzee, the animal is likely to examine and play with it for a time, and then move on to something else. In the same circumstances, an orangutan is likely to pretend to ignore the tool at first; later, in the zookeeper’s absence, the orangutan may use the screwdriver to try to dismantle its cage.
Summary
Naturalist: Different primate species behave differently. If a zookeeper leaves a screwdriver near a chimpanzee, it will likely play with it for a while and then lose interest. In contrast, an orangutan might pretend not to care at first, but later, when the zookeeper is gone, it may try to use the screwdriver to take apart its cage.
Strongly Supported Conclusions
Different nonhuman primates may engage with the same tool in different ways.
By pretending to ignore the screwdriver until the zookeeper is gone, some orangutans try to deceive zookeepers.
A
Orangutans are the most intelligent of nonhuman primates.
Unsupported. The stimulus does not compare the intelligence or orangutans to the intelligence of any other nonhuman primates.
B
Orangutans have better memories than chimpanzees have.
Unsupported. The stimulus doesn’t give any information about the memories of orangutans and chimpanzees. Just because an orangutan returns to the tool later while the chimpanzee loses interest does not mean that the orangutan has a better memory.
C
Some nonhuman primates are capable of deception.
Strongly supported. Because the orangutan pretends to ignore the screwdriver and then later tries to dismantle its cage with it, we can conclude that it is capable of deception.
D
Orangutans dislike being caged more than chimpanzees do.
Unsupported. We do not know that orangutans dislike being caged more than chimpanzees do simply based on the fact that an orangutan may try to dismantle its cage when given a screwdriver.
E
Not all nonhuman primates understand tool use.
Unsupported. Just because the chimpanzee does not try to use the screwdriver as a tool does not mean that it does not understand tool use.
A
fails to take into account the possibility that the standards by which productivity is judged might vary across different divisions of a corporation
B
overlooks the possibility that a corporation as a whole can have a profitable year even though one division of the corporation does not
C
fails to justify its use of one group’s performance as the basis for a conclusion about a wholly different group
D
reaches a conclusion about the performance of one member of a group merely on the basis of the performance of the group as a whole
E
takes for granted that an employee who has an unproductive year will not be exceptionally productive in subsequent years
For the first few weeks after birth, the dunnart has such poor control over its respiratory muscles that it cannot use them to breathe. Instead, this tiny marsupial breathes through its thin skin, which gradually thickens as the dunnart matures inside its mother’s pouch. The dunnart is unique among warm-blooded animals, the rest of which need thick skin throughout their lives to maintain body temperature and reduce water loss.
"Surprising" Phenomenon
Why do dunnarts, which are born with thin skin, survive even though all other warm-blooded animals need thick skin from birth in order to maintain their body temperature and reduce water loss?
Objective
The correct answer will be a hypothesis that explains a key difference between how young dunnarts maintain their body temperature and reduce water loss and how all other warm-blooded animals maintain their body temperature and reduce water loss. This difference will help to explain how dunnarts can survive with thin skin at the beginning of their lives, while all other warm-blooded animals need thick skin from birth.
A
The dunnart’s respiratory muscles begin to develop a few days after birth.
We know that baby dunnarts breathe through their thin skin because they cannot yet control their respiratory muscles. But (A) does not explain how they maintain their body temperature and reduce water loss before those respiratory muscles develop.
B
The dunnart’s body temperature is higher than that of many other warm-blooded animals.
Having a higher body temperature does not explain how baby dunnarts maintain that body temperature and reduce water loss with thin skin.
C
Adult dunnarts experience more heat and water loss through their skin than other adult marsupials do.
Dunnarts’ skin gradually thickens as they mature. So we know that adult dunnarts can maintain their body temperature and reduce water loss, even if they don’t do so as efficiently as other adult marsupials. We need an explanation for how baby dunnarts can do this with thin skin.
D
Its mother’s pouch keeps a newborn dunnart warm and reduces water loss through its skin.
This explains the key difference in how young dunnarts maintain body temperature and reduce water loss. While other warm-blooded baby animals need thick skin to survive, its mother’s pouch keeps a baby dunnart warm and reduces water loss, so the baby can survive with thin skin.
E
Some dunnarts live where daytime temperatures are high and the climate is dry.
This does not help to explain how baby dunnarts can survive with thin skin. Even if they are in a warmer and drier climate, we still need to know how they are able to maintain their body temperature and reduce water loss.