{"id":5788,"date":"2026-06-23T17:02:19","date_gmt":"2026-06-23T17:02:19","guid":{"rendered":"https:\/\/18kenglish.com\/bioluminescence-in-nature-elementary\/"},"modified":"2026-06-23T17:02:22","modified_gmt":"2026-06-23T17:02:22","slug":"bioluminescence-in-nature-elementary","status":"publish","type":"post","link":"https:\/\/18kenglish.com\/th\/bioluminescence-in-nature-elementary\/","title":{"rendered":"Bioluminescence in Nature | Elementary ESL Worksheet PDF"},"content":{"rendered":"
\n📄 Download Printable PDF Worksheet<\/a><\/p>\n

Free, classroom-ready, one click \u2014 includes answer key on page 3.<\/p>\n<\/div>\n

\n\"Bioluminescence
\n<\/figure>\n

Reading Worksheet \u2014 Elementary (C) | tahricteaches.com<\/p>\n

\n

Some living things can make their own light. This light is called bioluminescence. It is not hot like fire. It is a soft, cool glow<\/strong>. We can see this light at night. Bioluminescence happens in the sea and on land. Many animals use it to live and stay safe.<\/p>\n

The deep \u0e21\u0e2b\u0e32\u0e2a\u0e21\u0e38\u0e17\u0e23<\/strong> is very dark. The sun cannot reach the bottom. But the water is not empty. Many \u0e2a\u0e34\u0e48\u0e07\u0e21\u0e35\u0e0a\u0e35\u0e27\u0e34\u0e15<\/strong> there make their own light. Some fish have lights on their heads. They glow blue or green in the dark water.<\/p>\n

On land, the firefly<\/strong> is famous for its light. On warm summer nights, fireflies fly in the air. Their small lights blink on and off. They use the light to find a friend. Many people love to watch them.<\/p>\n

Why do animals make light? Some use light to find food. The light can attract<\/strong> small fish or bugs. When the food comes close, the animal can eat it. Other animals use light to scare away enemies. This keeps the animal safe. Light is a useful tool for many animals.<\/p>\n

Animals make light with a chemical inside their bodies. The chemical mixes with air and makes a glow. This is a clever trick from nature. Scientists study these animals to learn more. Their natural light is truly amazing.<\/p>\n<\/div>\n

\u0e01. \u0e04\u0e33\u0e28\u0e31\u0e1e\u0e17\u0e4c<\/h2>\n
\n
    \n
  1. glow ____<\/li>\n
  2. ocean ____<\/li>\n
  3. dark ____<\/li>\n
  4. firefly ____<\/li>\n
  5. creature ____<\/li>\n
  6. attract ____<\/li>\n
  7. chemical ____<\/li>\n
  8. signal ____<\/li>\n
  9. deep ____<\/li>\n
  10. nature ____<\/li>\n<\/ol>\n
      \n
    • a. very large body of salt water<\/li>\n
    • b. world of plants, animals, and land around us<\/li>\n
    • c. substance that can mix and react to make something new<\/li>\n
    • d. small flying insect that makes light at night<\/li>\n
    • e. having little or no light<\/li>\n
    • f. living animal<\/li>\n
    • g. make something come closer<\/li>\n
    • h. sign or action that sends a message<\/li>\n
    • i. soft, steady light that is not hot<\/li>\n
    • j. far down from the top<\/li>\n<\/ul>\n<\/div>\n
      \n\"Bioluminescence
      \n<\/figure>\n

      \u0e02. \u0e08\u0e23\u0e34\u0e07\u0e2b\u0e23\u0e37\u0e2d\u0e40\u0e17\u0e47\u0e08<\/h2>\n
        \n
      1. ____   Bioluminescence is a kind of light.<\/li>\n
      2. ____   The light from bioluminescence is very hot.<\/li>\n
      3. ____   The deep ocean is very dark.<\/li>\n
      4. ____   The sun reaches the bottom of the deep ocean.<\/li>\n
      5. ____   Fireflies make light at night.<\/li>\n
      6. ____   Fireflies live deep in the ocean.<\/li>\n
      7. ____   Some animals use light to find food.<\/li>\n
      8. ____   Animals make light with a chemical inside their bodies.<\/li>\n
      9. ____   No animals use light to scare away enemies.<\/li>\n
      10. ____   Bioluminescence happens only on land.<\/li>\n<\/ol>\n

        \u0e04. \u0e40\u0e15\u0e34\u0e21\u0e04\u0e33\u0e43\u0e19\u0e0a\u0e48\u0e2d\u0e07\u0e27\u0e48\u0e32\u0e07<\/h2>\n
        \n\u0e04\u0e25\u0e31\u0e07\u0e04\u0e33\u0e28\u0e31\u0e1e\u0e17\u0e4c:<\/strong> ocean, firefly, attract, glow, dark, chemical, signal, creature\n<\/div>\n
          \n
        1. The deep ___ is full of animals that make light.<\/li>\n
        2. A ___ blinks its small light on summer nights.<\/li>\n
        3. Some animals use light to ___ small fish or bugs.<\/li>\n
        4. The soft, cool light that animals make is called a ___.<\/li>\n
        5. The bottom of the deep sea is very ___.<\/li>\n<\/ol>\n

          \u0e07. \u0e04\u0e33\u0e16\u0e32\u0e21\u0e40\u0e1e\u0e37\u0e48\u0e2d\u0e17\u0e14\u0e2a\u0e2d\u0e1a\u0e04\u0e27\u0e32\u0e21\u0e40\u0e02\u0e49\u0e32\u0e43\u0e08<\/h2>\n
            \n
          1. Why is the deep ocean dark?<\/li>\n
          2. How do fireflies use their light?<\/li>\n
          3. How do animals make their own light?<\/li>\n<\/ol>\n

            E. \u0e04\u0e33\u0e16\u0e32\u0e21\u0e40\u0e1e\u0e37\u0e48\u0e2d\u0e01\u0e32\u0e23\u0e2d\u0e20\u0e34\u0e1b\u0e23\u0e32\u0e22<\/h2>\n
              \n
            1. Would you rather see fireflies on land or glowing animals in the ocean? Why?<\/li>\n
            2. If you could glow in the dark, when would you use your light?<\/li>\n<\/ol>\n
              \nAnswer Key (click to reveal)<\/summary>\n
              \n

              \u0e01. \u0e04\u0e33\u0e28\u0e31\u0e1e\u0e17\u0e4c:<\/strong> 1-i, 2-a, 3-e, 4-d, 5-f, 6-g, 7-c, 8-h, 9-j, 10-b<\/p>\n

              \u0e02. \u0e08\u0e23\u0e34\u0e07\/\u0e40\u0e17\u0e47\u0e08:<\/strong> 1-T, 2-F, 3-T, 4-F, 5-T, 6-F, 7-T, 8-T, 9-F, 10-F<\/p>\n

              C. Fill Blanks:<\/strong> 1-ocean, 2-firefly, 3-attract, 4-glow, 5-dark<\/p>\n

              \u0e07. \u0e04\u0e27\u0e32\u0e21\u0e40\u0e02\u0e49\u0e32\u0e43\u0e08:<\/strong><\/p>\n

                \n
              1. The deep ocean is dark because the sun cannot reach the bottom.<\/li>\n
              2. Fireflies use their light to find a friend.<\/li>\n
              3. They make light with a chemical inside their bodies that mixes with air.<\/li>\n<\/ol>\n<\/div>\n<\/details>\n

                \u00a9 Tahric Teaches | tahricteaches.com<\/p>","protected":false},"excerpt":{"rendered":"

                📄 Download Printable PDF Worksheet Free, classroom-ready, one click \u2014 includes answer key on page 3. 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