Algae is a primitive form of life, a single-celled or simple multiple-celled organism that is able to conduct the process of photosynthesis. It is generally found in water but can also be found elsewhere, growing on such surfaces as rocks or trees. The various types of algae are classified according to pigment.

Blue-green algae, or Cyanophyta, can grow at very high temperatures and under high- intensity light. This type of algae is the oldest form of life with photosynthetic capabilities. Fossilized remains of blue-green algae more than 3.4 billion years old have been found in parts of Africa.

Green algae, or Chlorophyta, is generally found in fresh water. It reproduces on the surfaces of enclosed bodies of water such as ponds or lakes and has the appearance of a fuzzy green coating on the surface of the water.

Brown algae, or Phaeophyta, grows in shallow, temperate water. This type of algae is the largest in size and is most recognizable as a type of seaweed. Its long stalks can be enmeshed on the ocean floor, or it can float freely on the ocean's surface.

Red algae, or Rhodophyta, is a small, delicate organism found in the deep waters of the subtropics. This type of algae has an essential role in the formation of coral reefs: it secretes lime from the seawater to foster the formation of limestone deposits.

According to the passage, red algae is ................

Câu hỏi liên quan

• Which of the following pairs is INCORRECT?

• It can be inferred from the passage that .............

• The word “bizarre” is closest meaning to ..........

ZUNIA12

• The word “they” in paragraph 3 refers to ___________.

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

• The author of this passage is most likely __________________ .

• The word “it” refers to __________

• Which of the following best summarizes this passage?

• According to the passage, which of the following factors might spoil the tourists’ fun at Mediterranean resorts and beaches?

• Ancient education generally focused its efforts on _______.

• The word “lies” in the first paragraph could be best be replaced by ______.

• When she published her first book, Carson was closest to the age of .........

• The tone of the passage is that of .................

• The paragraph following the passage most likely discusses:

• It can be inferred from the passage that brain size is assumed to ___________.

• It can be inferred from the passage that ___________.

• Which of the following is a kind of petal?

• The tone of the passage is that of __________

• The word “it” in paragraph 2 refers to ______.

• What is the author’s main purpose in the first paragraph of to passage?