Lesson A2: Needs of Living Things

Key Ideas   Unit Checklist

  Video Lesson

Watch this video to take a trip to a beaver pond to investigate the needs of living things.

  Lesson A2: Needs of Living Things

A Snowy Owl Success Story

Someone found a snowy owl far from its arctic home. It was very thin and sick. The local rescue society nursed it back to health. Then, they released it back into the wild. To nurse a wild animal back to health, a person must know its needs.
Reading and Materials for This Lesson

Science in Action 7
Reading: Pages 12–15

Materials:
large jar, clean sand or gravel, activated charcoal, soil, small plants, rocks, water

Figure A.1.2.1 – The snowy owl is native to the Canadian arctic.
Figure A.1.2.2 – A snowy owl hunts a lemming.

 Watch More

Owl Rescue

This video tells the story of this owl’s rescue, nursing, and release. Watch for clues about what a snowy owl needs every day to be healthy. How are its needs different from yours? How are they the same?

Termite City

Every organism needs a place to live. Some animals, such as birds, build their homes. Termites take it much further. They build skyscrapers! In Africa, where the weather is very hot and, when it is not hot, rain is heavy, the termites need to stay cool and dry. Their mound has hollow tubes that work as air conditioning to keep them cool. During rains, they can move up their structure away from floodwater.


Figure A.1.2.3 – This towering structure is a termite mound.
Figure A.1.2.4 – Inside, termites maintain the mound and care for eggs.

  Try It!

Build an Online Habitat

Now that you know about what organisms need to live, try building your own habitats for various organisms by using a fun online game.

Instructions:

1. Visit the Build an Online Habitat Website . WARNING: Turn your sound down. This website has audio enabled as soon as you visit. You will need Adobe Flash activated on your computer for this website to work. If you don't have Flash activated, that's OK, just skip this activity and move on the next one below.

2. Click the “Show Instructions” graphic in the top right corner. Read the instructions carefully. Building is very simple. Click the small icons to change the precipitation, animal, biome, and vegetation.

3. Experiment! As you change the icons, watch the compatibility meter. You are trying to get the highest reading possible on the meter. In addition, note which changes make the compatibility meter drop.
Questions:

Think about the following question very carefully. Then, type or write your answer. After you have your answer, click the question for feedback.

Ecosystems contain animals, weather, and vegetation that are suited to each other. Things that do not match usually disappear from or avoid the ecosystem. For example, a lizard requires warm conditions. Putting a lizard into a cold, snowy ecosystem just won’t work! The lizard will not survive.



  Try It!

Make Your Own Ecosystem

This activity allows you to make your own ecosystem and to explore how it works.

Materials:

  • air-tight glass container (such as a mason jar, perhaps a clean large salsa jar)
  • clean sand or gravel
  • landscape fabric or other thin filter
  • activated charcoal (You can get this from a pet store.)
  • soil (Cactus soil is best because it is quite gravelly.)
  • plants (Small slow-growing plants and mosses are best.)
  • decorative items (such as various colours and shapes of small rocks)
  • water

You will construct a closed ecosystem. Earth is a closed ecosystem. As you can imagine, yours will be much smaller!


Figure A.1.2.5 – You will be making a garden in a jar similar to this one. Photo by Christopher Michel.
Instructions:

    1. Clean an air-tight glass container (such as a mason jar) thoroughly. It must be very clean or molds will grow -- and you do not want them as part of this ecosystem!

    2. Add a 2- to 5-cm layer of clean coarse sand or fine gravel to the bottom of the jar. Aquarium sand works very well. This will provide a drainage layer and water basin for excess water. Place the landscape fabric filter over this layer.

    3. Add a thin layer of activated charcoal on top of the sand. This will act as a filter to keep your jar clean.

    4. Add a 5- to 10-cm layer of good-draining soil. (Cactus soils works very well.)

    5. Add some decorative items such as rocks.

    6. Add some plants and moss. Small slow-growing plants work best.

    7. Water your plants. Add enough water so the sand layer is moist. You will need very little.

    8. Put the lid on your jar and place it near a window but not in direct sunlight. It will become too hot in direct sunlight and your plants might cook.


Questions:

Think about the following questions very carefully. Then, type or write your answers. After you have your answers, click the questions for feedback.

Here, a community of plants live together in a jar. They share the same living space. They grow roots into the soil. They use the air inside the jar for photosynthesis. This is a simple ecosystem.
What do plants need to live? The jar provides water and a place to live. Sunlight provides them with energy. The soil provides some nutrients, so the plants receive the “food” they require. Trapped in the jar is also a supply of air, which the plants need for gas exchange. The jar ecosystem provides everything the plants need to live. This may change over time. Because the jar garden is sealed, some things the plants need may be used completely, but the jar garden ecosystem likely will not encounter that problem for a long time.
Plants use carbon dioxide in the air. Bugs would help the plants because they breathe out carbon dioxide. Bugs produce waste, which can help the plants. The waste has nutrients they can use for food. However, on the down side, bugs might eat the plants.
The plants need water, just as we do. Without it, they eventually will die.
This is an interesting question, and the answer depends on several factors. The plants need food, but no plant food was added to the jar. The soil has some nutrients (food) for the plants, but that eventually may be all used. The plants may also has insufficient amounts of carbon dioxide. They need this gas to carry out photosynthesis. It some cases, when a jar ecosystem such as this is built, microorganisms (organisms too small to see) are in the jar because they entered when the soil and plants were put it. These microorganisms breathe and may produce enough carbon dioxide and wastes to provide the gases and nutrients the plants need.
A sealed jar may result in some of the plant’s needs not being met. Plants need food and fresh air. You could give them plant food. You could open the jar’s lid to give them fresh air. With all their needs met, the plants should stay healthy and grow.






  Make sure you have understood everything in this lesson. Use the Self-Check below, and the Self-Check & Lesson Review Tips to guide your learning.

Unit A Lesson 2 Self-Check

Instructions


Complete the following 6 steps. Don't skip steps – if you do them in order, you will confirm your understanding of this lesson and create a study bank for the future.

  1. DOWNLOAD the self-check quiz by clicking here.

  2. ANSWER all the questions on the downloaded quiz in the spaces provided. Think carefully before typing your answers. Review this lesson if you need to. Save your quiz when you are done.

  3. COMPARE your answers with the suggested "Self-Check Quiz Answers" below. WAIT! You didn't skip step 2, did you? It's very important to carefully write out your own answers before checking the suggested answers.

  4. REVISE your quiz answers if you need to. If you answered all the questions correctly, you can skip this step. Revise means to change, fix, and add extra notes if you need to. This quiz is NOT FOR MARKS, so it is perfectly OK to correct any mistakes you made. This will make your self-check quiz an excellent study tool you can use later.

  5. SAVE your quiz to a folder on your computer, or to your Private Files. That way you will know where it is for later studying.

  6. CHECK with your teacher if you need to. If after completing all these steps you are still not sure about the questions or your answers, you should ask for more feedback from your teacher. To do this, post in the Course Questions Forum, or send your teacher an email. In either case, attach your completed quiz and ask; "Can you look at this quiz and give me some feedback please?" They will be happy to help you!


Self-Check Time!
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Self-Check Quiz Answers

Click each of the suggested answers below, and carefully compare your answers to the suggested answers.

If you have not done the quiz yet – STOP – and go back to step 1 above. Do not look at the answers without first trying the questions.

Desert animals have many adaptations to desert life. For example, the thorny devil lizard lives in the desert, but, similar to all organisms, it needs water. No pooled water is available, but water is available if the organism knows how to get it. And the lizard does! In the mornings, dew settles in the cool air. Special scales on the lizard’s skin absorb the dew and funnel it to its mouth so it can drink it.
Eventually, the species will die out and become extinct. For example, many polar bears in northern Canada are going hungry.

Polar bears hunt and eat seals. The seals swim too fast for the bears to catch them in the water. Instead, the bears must catch them on the sea ice when the seals come up for air.

When the ice melts the bears cannot hunt. If all the arctic sea ice melts, the polar bears may all die.
Many plants survive long months completely frozen. In the autumn, their stems die back to their roots. The roots go dormant, which means they do not need any air or food. The roots thaw in the spring. Energy stored in the roots helps the plants grow new leaves and flowers.
Almost all living organisms on Earth have five basic needs: water, food, energy, oxygen, and suitable living conditions. Scientists look for planets that have sunlight energy similar to our planet. They look for signs of water, and they are look for signs of oxygen. Scientists suspect that alien life might have the same basic needs as life on Earth does.
Yes, some plants can live just on rock, sunlight, water, and air. They are the first organisms to occupy a lifeless area, such as a region devastated by a volcanic eruption. For example, after Mount St. Helens erupted in Washington State in 1980, lupins were the first plants to grow on the rocky ash flow.

These plants have special structures on their roots to make food. The lupins made it possible for other plants and animals eventually to move back into the area.