Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 44 to 50.
Social parasitism involves one species relying on another to raise its young. Among vertebrates, the best known social parasites are such birds as cuckoos and cowbirds; the female lays egg in a nest belonging to another species and leaves it for the host to rear.
The dulotic species of ants, however, are the supreme social parasites. Consider, for example, the unusual behavior of ants belonging to the genus Polyergus. All species of this ant have lost the ability to care for themselves. The workers do not forage for food, feed their brood or queen, or even clean their own nest. To compensate for these deficits, Polyergus has become specialized at obtaining workers from the related genus Formica to do these chores.
In a raid, several thousand Polyergus workers will travel up to 500 feet in search of a Formica nest, penetrate it, drive off the queen and her workers, capture the pupal brood, and transport it back to their nest. The captured brood is then reared by the resident Formica workers until the developing pupae emerge to add to the Formica population, which maintains the mixed-species nest. The Formica workers forage for food and give it to colony members of both species. They also remove wastes and excavate new chambers as the population increases.
The true extent of the Polyergus ants' dependence on the Formica becomes apparent when the worker population grows too large for existing nest. Formica scouts locate a new nesting site, return to the mixed-species colony, and recruit additional Formica nest mates. During a period that may last seven days, the Formica workers carry to the new nest all the Polyergus eggs, larvae, and pupae, every Polyergus adult, and even the Polyergus queen.
Of the approximately 8,000 species of ants in the world, all 5 species of Polyergus and some 200 species in other genera have evolved some degree of parasitic relationship with other ants.
Which of the following statements best represents the main idea of the passage?
A. Ants belonging to the genus Formica are incapable of performing certain tasks
B. The genus Polyergus is quite similar to the genus Formica
C. Ants belonging to the genus Polyergus have an unusual relationship with ants belonging to the genus Formica
D. Poltergus ants frequently leave their nests to build new colonies
Đáp án C
Giải thích: Đoạn đầu của bài đọc nói về các mối quan hệ cộng sinh trong thế giới tự nhiên để dẫn dắt vào loài kiến cộng sinh. Sau đó tác giả làm rõ hơn về loài kiến thuộc chi Polyergus cộng sinh với loài kiến thuộc chi Formica.
Như vậy phương án C. Ants belonging to the genus Polyergus have an unusual relationship with ants belonging to the genus Formica. = Kiến thuộc chi Polyergus có một mối quan hệ không bình thường với kiến thuộc chi Formica; là phương án có nghĩa sát nhất.
A. Ants belonging to the genus Formica are incapable of performing certain tasks = Kiến thuộc chi Formica không có khả năng thực hiện một số nhiệm vụ nhất định.
Kiến thuộc chi Polyergus chứ không phải chi Formica mới không có khả năng thực hiện một số nhiệm vụ nhất định.
B. The genus Polyergus is quite similar to the genus Formica. = Các chi Polyergus là khá giống với các chi Formica.
Không có thông tin như vậy trong bài.
D. Poltergus ants frequently leave their nests to build new colonies = Loài kiến Poltergus thường xuyên rời khỏi tổ của chúng để xây dựng thuộc địa mới.
Không có thông tin như vậy trong bài.