Make sure you have understood everything in this section (Lessons A1, A2, and A3).
Use the Self-Check below, and the Self-Check & Lesson Review Tips to guide your learning.
This is also a good time to visit your Section 1 Checklist to make sure you have completed all the recommended learning activities.

Unit A Section 1 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 section 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 the lessons of this section 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!

|


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.

This is indeed an ecosystem. Various organisms interact with each other on and in the decaying log. They find shelter in the log. The organisms also interact with nutrients in the decaying wood as well as from water and sunlight in the environment.
The decaying log is a dead tree. Therefore, the decaying log is an abiotic, or non-living, factor in the ecosystem. When the tree was living, it was a biotic, or living, factor in the system.
Living organisms have five basic needs: water, a place to live, food, light, and air.  In the photo, the ground is very dry and cracked. There are no living plants. Perhaps the area has received very little or no rainfall. This tree’s need for water was not met, and it died.
The barnacles benefit from the whale in two ways. The whale feeds on plankton so it is always taking the barnacles to food supplies. Second, the barnacles are protected from predators. If they were attached to a stationary object, they could not get away from the fish, snails, and starfish that eat them. The barnacles benefit and the whale is not affected either negatively or positively. This is a commensalistic symbiotic relationship.
All symbiotic relationships benefit at least one of the two species involved. The other species involved may also benefit, or it may be harmed or not affected either way. Symbiotic relationships strengthen ecosystems. They give adaptive advantages to the species involved. Interactions that harm both species do not offer any advantage. These relationships usually are of rather short duration.