Orchids are unique in having the most highly developed of all blossoms, in which the usual male and female reproductive organs are fused in a single structure called the column. The column is designed so that a single pollination will fertilize hundreds of thousands, and in some cases millions, of seeds, so microscopic and light they are easily carried by the breeze. Surrounding the column are three sepals and three petals, sometimes easily recognizable as such, often distorted into gorgeous, weird, but always functional shapes. The most noticeable of the petals is called the labellum, or lip. It is often dramatically marked as an unmistakable landing strip to attract the specific insect the orchid has chosen as its pollinator. To lure their pollinators from afar, orchids use appropriately intriguing shapes, colors, and scents. At least 50 different aromatic compounds have been analyzed in the orchid family, each blended to attract one, or at most a few, species of insects or birds. Some orchids even change their scents to interest different insects at different times.

   Once the right insect has been attracted, some orchids present all sorts of one-way obstacle courses to make sure it does not leave until pollen has been accurately placed or removed. By such ingenious adaptations to specific pollinators, orchids have avoided the hazards of rampant crossbreeding in the wild, assuring the survival of species as discrete identities. At the same time they have made themselves irresistible to collectors.

Which of the following is a kind of petal?

Câu hỏi liên quan

• The word "vulnerable" in paragraph 4 is closest in meaning to .............

• With which of the following statements would the author agree?

• Which word is similar in meaning to the word “glue” ?

ZUNIA12

• The word “There” in paragraph 5 refers to ____.

• Doctors have tentatively concluded that cell phones may .............

• This article is about ________.

• The phrase ‘suck out’ in paragraph 2 is closest in meaning to which of the following?

• In general, what did the Brazilian students think about people who are late?

• The word cherished in paragraph 1 is closest in meaning to _______________

• The passage implies that Melville stayed in Tahiti because____________.

• According to the passage, travel books, biographies and memoirs ______.

• Why does the author believe that the Mandans were skilled farmers?

• Around what time did the university begin to appear?

• Which of the following would most likely NOT be reflected in a person's costume, as it is defined in the passage?

• The phrase “in season” in line 1 refers to ________ .

• The word "all-inclusive" in the passage mostly means ................

• The word “interfere” in paragraph 2 most nearly means ..........

• When is the most famous football game held annually?

• It can be inferred from the passage that if a person remembers a piece of information for two days, this is probably ............

• Why does the author mention "artistic, political, or pedagogic communication" in line 14-15?