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How Corals Build the Reef — Reading Comprehension

Grades
2
3
4
Standards
RI.3.8
RI.4.8
PRINT+DIGITAL RESOURCE
This learning resource is available in interactive and printable formats. The interactive worksshet can be played online and assigned to students. The Printable PDF version can be downloaded and printed for completion by hand.

Perfect For:

👩‍🏫 Teachers
  • • Reading comprehension practice
  • • Auto-graded assessments
  • • Literacy skill development
👨‍👩‍👧‍👦 Parents
  • • Reading practice at home
  • • Comprehension improvement
  • • Educational reading time
🏠 Homeschoolers
  • • Reading curriculum support
  • • Independent reading practice
  • • Progress monitoring

Reading Features:

📖
Reading Passage
Engaging fiction or nonfiction text
Comprehension Quiz
Auto-graded questions
📊
Instant Feedback
Immediate results and scoring
📄
Printable Version
Download for offline reading

About This Reader

This passage explains the fascinating process of how coral polyps build the Great Barrier Reef. It details the life cycle of coral, from free-swimming larvae to colony formation. The text describes how polyps secrete calcium carbonate skeletons, gradually building up the reef structure over thousands of years. It emphasizes the slow nature of reef formation and the importance of conservation efforts. The passage uses the analogy of underwater cities to illustrate the complex ecosystem created by corals. Keywords: coral polyps, reef formation, calcium carbonate, marine ecosystem, coral conservation, Great Barrier Reef, underwater cities.

Corals are the master builders of the Great Barrier Reef. These tiny animals, called polyps, create the massive structures we see as coral reefs. The process begins when free-swimming coral larvae attach to underwater rocks or other hard surfaces near the coast. Once attached, they begin to divide and grow, forming colonies. As they grow, the polyps secrete a hard calcium carbonate skeleton around themselves for protection. This skeleton becomes the structure of the coral reef. Over time, as more polyps live and die, their skeletons build up layer by layer. This process is very slow – it can take coral reefs thousands of years to form. 

That's why it's so important to protect existing reefs. The coral polyps work tirelessly, generation after generation, to create and maintain these underwater cities that provide homes for countless sea creatures.

What are the main builders of coral reefs?

FishCoral polypsSea turtlesAlgae

Where do coral larvae first attach?

To other fishTo underwater rocks or hard surfacesTo the ocean surfaceTo seaweed

What do coral polyps secrete to protect themselves?

SlimeSoft tissueCalcium carbonate skeletonInk

How long can it take for coral reefs to form?

A few monthsSeveral yearsHundreds of yearsThousands of years

Why does the passage say it's important to protect existing reefs?

Because they're beautifulBecause they're good for tourismBecause they take a very long time to formBecause they produce oxygen

What does the passage compare coral reefs to?

Underwater citiesFloating islandsMountain rangesDesert oases

Common Core Standards Covered

RI.3.8
Describe the logical connection between particular sentences and paragraphs in a text (e.g., comparison, cause/effect, first/second/third in a sequence).
RI.4.8
Explain how an author uses reasons and evidence to support particular points in a text.

Grade Levels:

Grade 2Grade 3Grade 4

Subjects:

elareadingscience

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