A basic principle of ecology is that population si...

Question

A basic principle of ecology is that population size is partly a reflection of available food resources. Recent
experiments suggest that the relationship is more complex than formerly thought. Specifically, the browsing of
certain rodents appears to trigger chemical reactions in food plants which, in turn, affect the size of the rodent
populations. Two examples of such regulation have been reported.
Berger has demonstrated the power of a naturally occurring chemical called 6-MBOA to stimulate reproductive
behavior in the mountain vole, a small mouse-like rodent. 6-MBOA forms in young grass in response to browsing
by voles. Berger experimented by feeding oats coated with 6-MBOA to non-breeding winter populations of voles.
After three weeks, she found a high incidence of pregnancy among females. Since the timing of reproduction is
crucial to the short-lived vole in an environment in which the onset of vegetative growth may be considerably
delayed, the phytochemical triggering of reproductive behavior represents a significant biological adaptation .
In an example reported by Bryant, plants appear to have developed a phytochemical defense against the
depredations of snowshoe hares in Canada. Every ten years, for reasons that are unclear, the hare population
swells. The result is overbrowsing of certain deciduous trees and shrubs. Bryant found that trees favored by the
hare produce young shoots high in terpene and phenolic resins, which discourage hare browsing. After treating
non-resinous willow twigs with resinous extracts and placing treated and untreated samples at hare feeding
stations, Bryant found that samples containing at least half of the resin concentration of natural twigs were
untouched. The avoidance of resinous shoots, he concludes, may play a role in the decline of the hare population
to normal levels.
Both of these reports suggest areas for further research. For example, data should be reviewed to determine
if periodic population explosions among lemmings (another small rodent living in a northern environment) occur
during years in which there is an early onset of vegetative growth; if so, a triggering mechanism similar to that
prompted by the vole may be involved .

16. The experiments described in the passage did each
of the following, EXCEPT .. .
(A) measure changes in the behavior of test animals
(B) measure changes in the populations of
experimental animals
(C) simulate a hypothesized phytochemical effect
in nature
(D) measure the consumption of foods by test
animals
(E) analyze the effects of food on breeding behavior

K. Melarillis · Accepted Answer

Hai! Kakak bantu jawab yaa.

Jawaban yang benar adalah: (E) analyze the effects of food on breeding behavior.

Soal ini meminta kita untuk mengidentifikasi hal-hal yang tidak dilakukan pada eksperimen di bacaan.

Mari kita cari informasi yang berkaitan dengan eksperimen pada pada paragraf 2. Terjemahan paragraf 2 adalah sebagai berikut:

Berger telah menunjukkan kekuatan bahan kimia alami yang disebut 6-MBOA untuk merangsang perilaku reproduksi pada tikus gunung, hewan pengerat kecil seperti tikus. 6 MBOA terbentuk di rumput muda sebagai respons terhadap penjelajahan oleh tikus. Berger bereksperimen dengan memberi makan gandum yang dilapisi dengan BOA 6-M ke populasi tikus musim dingin yang tidak berkembang biak. Setelah tiga minggu, dia menemukan insiden kehamilan yang tinggi di antara wanita. Karena waktu reproduksi sangat penting untuk tikus berumur pendek di lingkungan di mana permulaan pertumbuhan vegetatif mungkin sangat tertunda, pemicu fitokimia dari perilaku reproduksi mewakili adaptasi biologis yang signifikan.

Dengan demikian dapat kita simpulkan bahwa eksperimen di bacaan tidak menganalisa efek makanan pada kebiasaan berkembang biak.

Jadi, jawaban yang benar adalah: (E) analyze the effects of food on breeding behavior.

Semoga membantu yaa.

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