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 "they" refers to ........

• The author mentions all of the following as concerns of telecommuting EXCEPT ________.

• The word “assessing” in paragraph 2 could best be replaced by ...........

ZUNIA12

• According to the passage, Melville’s early novels were ...............

• The word “they” in the last paragraph refers to ............

• According to paragraph 1, which of the following is NOT true?

• The word “pseudonym” in the passage refers to ___________.

• Which of the following can be inferred from the passage?

• How did Juliette Davidson benefit from the experience of her first job?

• The word “sustain” in paragraph 3 is closest in meaning to__________.

• According to the passage, when will information stay in your short-term memory?

• What do the Hindu people think about marriage?

• After which year did the town really begin developing?

• Which of the following can be inferred from the passage?

• Which of the following would NOT be a problem for the construction plan?

• As it can be inferred from the passage, what benefits does Internet II have over the Internet I?

• A paragraph following the passage would most probably discuss_________.

• According to the passage, all of the following contributed to the spread of English around the world EXCEPT .............

• The phrase “more achievement oriented” in the paragraph 6 is closest in meaning to ______.

• According to the text, future post graduates should start working as teachers _______