Passage 2 | Animal behavior
Different animals develop different ways of interacting with other members of the same species. Some live their entire lives as solitary individuals, whereas others are unable to survive without the systems of support found in communal living environments. [A] Nearly all of the 35,000 known spider species fall into the former category. [B] They live alone and will fiercely protect their established territory from ) all other creatures. [C] Yet, there are around 40 species of spiders that have been observed to practice various forms of sociality. [D] The rarity of this makes these species popular subjects of research.
In studying social spider species, it is tempting to compare their communities with those of the widely understood social insects —various species of ants, termites, bees, etc. While such spiders and insects do share some similarities in the ways they behave, in many important areas the two differ greatly. First of all, every spider within a colony could, conceivably, fulfill all of its survival needs on its own if it had to. Members of an ant or termite ‘5 colony, on the other hand, rely heavily on the collective; they could not exist without it.
If all social spiders possess this natural self-sufficiency, what is it that compels them to seek out others to build a home? Although the specific reasons for this are not yet known, there are some obvious advantages to communal living. Like insects, spiders in the same community work together to capture prey. Not only do they collaborate on the building of large webs for snaring food; in some species the inhabitants of a colony work collectively to ambush any insects that might venture near their nest. In this way, the spiders are able to catch larger prey in greater quantities than they could if they were hunting alone, and the food is usually shared by the entire group.
This similarity is significant, but in most other matters the parallels between 5 social spiders and insects cease. One of the most striking differences between colonies of spiders and those of social insects deals with their overall organizational structures. The insects have developed a strict hierarchical system, with specific duties assigned to specific members who are genetically programmed to carry them out. A single queen is responsible for laying the eggs for the entire community, as well as directing the other insects; male drones have the task of mating with the queen; and female and male workers perform repairs, look after the young, and locate sources of food. In some species there are even special soldier insects physically designed for battle.
In spider societies, on the other hand, there is a complete lack of this type of organization, which is what enables social spiders to maintain greater self-sufficiency than social insects do. Individuals are not 5 bred to carry out specific tasks. There are no genetically designated drones, workers, or soldiers. Instead, each spider shares in duties such as web maintenance, hunting, and the protection of offspring. Egg sacs are o collectively guarded and watched over, as are the young spiders once they hatch. In place of a single colony queen, every female in a spider society retains the ability to reproduce. Thus, these spiders enjoy the benefits of cooperative work-for example, being able to conserve body energy by distributing tasks like web making throughout the entire group-but they achieve them by way of a very different method than insects do.
The study of social spider species developed relatively recently compared with that of social insects. For this reason, many observers are tempted to liken the former to the latter. Upon close inspection, however, spiders that live collectively behave differently from their insect counterparts. Some experts actually claim that social spiders more closely resemble a pride of lions than they do a hive of bees or a colony of ants. In addition, varying degrees of cooperation are displayed even within the small number of spider species that do exhibit such behavior. They range from adult spiders that merely care for their young briefly before abandoning them to full-fledged colonies that can contain tens of thousands of members. The uniqueness of these creatures clearly demands further research.
13. The word others in the passage refers to
14. According to paragraph 1, the vast majority of spiders
(A) do not form cooperative groups
(B) are different from most animals
(C) do not establish territorial boundaries
(D) sometimes engage in social behavior
15. In paragraph 2, how does the author support the argument that social spiders are different from social insects?
(A) By stating the differences between how social spiders and insects are studied
(B) By contrasting the levels of independence of individual spiders and insects
(C) By citing specific behavioral differences between social spiders and insects
(D) By explaining how a spider’s survival needs are less complex than an insect’s
16. The word compels in the passage is closest in meaning to
17. The word venture in the passage is closest in meaning to
18. It can be inferred from paragraph 4 that most female social insects
(A) do not bear young
(B) are somewhat self-sufficient
(C) are similar to female spiders
(D) do not care for offspring
19. The word striking in the passage is closest in meaning to
20. Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.
(A) The practice of web making performed by spiders allows them to achieve greater work efficiency than social insects can.
(B) Animal societies function at their best when all members participate in activities that benefit the entire group.
(C) By sharing tasks such as the spinning of webs, spiders are able to conserve their energy for other uses.
(D) Though they utilize different techniques from insects’, social spiders also benefit from the advantages of group cooperation.
21. Why does the author mention the protection of egg sacs in paragraph 5?
(A) To offer a reason for the absence of self- sufficiency seen in social spiders
(B) To illustrate how the lack of a single queen benefits a spider colony
(C) To describe the hierarchical organization that social spiders develop
(D) To give an example of work that is distributed throughout a spider colony
22. According to paragraph 6, spiders can be considered social if they
(A) act similar to certain predatory mammals
(B) reproduce more than once during their lives
(C) become members of a large insect colony
(D) make some effort to protect their offspring
23. The word counterparts in the passage is closest in meaning to
24. According to the passage, all of the following are differences between social spiders and social insects EXCEPT
(A) their ability to survive outside a community
(B) their rates of female fertility
(C) their practice of collective hunting
(D> the division of labor within a community
25. Look at the four squares m that indicate where the following sentence could be added to the passage.
Even newborn spiders are forced to fend for themselves, as the females of these species spend no time in caring for their young.
Where would the sentence best fit?
Click on a square (H to add the sentence to the passage.
26. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.
The small fraction of spider species that build collective homes may exhibit some similarities to social insects, but they are actually quite different.
(A) Social insects such as ants, termites, and bees have received more attention from researchers in the past than social spiders have.
(C) Some advantages of group living, such as collaborating to perform repairs and acquire food, are shared by both social spiders and insects.
(E) Compared to the hierarchical nature of insect colonies, spider societies have a much looser organizational structure, and tasks are more universally distributed.
(B) Unlike social insects, which cannot live apart from their colonies, the individuals in spider communities do not give up their potential fc independence.
(D) Working in large groups, social spiders can catch more prey than they could if they were hunting on their own.
(F) Even social spiders that show low levels of cooperation are more similar to insects than they are to other types of animal species.
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