Learning Activities

Biosphere lab report                                                First name Last name
February 2, 2018                                                                  7th Grade Science Period
Mrs. Zysk

Sample introduction (in part)

Ecology is the study of the living organisms and how they relate to each other and to the non-living things in their environment.  Living things, or biotic factors, in an environment include plants, animals and bacteria.  Non-living things, or abiotic factors, in an environment include water, soil, sunlight and temperature.  The kinds and amount of abiotic factors in a certain environment determine which biotic things can survive in the environment.  For example, a tropical plant that needs lots of water will not survive in a desert that gets very little rainfall.
Biotic factors in an ecosystem have different ways that they get food and nutrients.  Producers usually are plants that are able to make their own food using the energy from sunlight, which they convert into glucose through the process of photosynthesis.  Consumers are other organisms, such as animals, that cannot make their own food and have to eat other living things to get food.  A herbivore is a consumer that only eats plants and a carnivore is a consumer that only eats meat or other animals.  Omnivores, such as humans, eat both plants and animals.
(You fill in the rest………)

Problem and hypothesis
In this experiment, the problem was whether a self contained, sealed (aquatic or terrestrial) ecosystem could be created that was balanced and could survive without any interaction with the outside, including air exchange.  The hypothesis was that if the correct balance of abiotic and biotic factors were added to the bottle ecosystem, then the ecosystem would survive and the living things would be alive and be able to live in the ecosystem.

Sample materials and methods

            In the experiment, an aquatic ecosystem was created.  The materials used to create the ecosystem are:  one clear 2 litter soda bottle, 600 ml of aged distilled water, 4 scoops of gravel, 4 Elodea water plants, 2 guppies and one water snail.
            To create the ecosystem, the soda bottle was rinsed and cleaned.  (If you cut the bottle, describe that)  The gravel was measured, rinsed with tap water and added to the bottle.  Aged distilled water was measured in a graduated cylinder and 600 ml was added to the bottle.   (Continue……)
            Figure 1 is a picture of what the bottle ecosystem looked like on the first day when it was created.

Sample results

            On the day the ecosystem was created, the temperature of the water was 25°F and the pH was 6.  The temperature was measured with a thermometer and the pH was measured using pH paper.
Observations were taken on day 3, 6, 10 and 12 (you have dates on the table, so use the correct day numbers) after the ecosystem was created.  On day 3 after the ecosystem, the guppy was not moving and was floating at the top of the water.  It is believed that it died.  In addition, the Elodea plants looked a bit brown, not as green as the first day.  The water was a little bit cloudy and particles could be seen floating in the water.
            On day 6,………………..  you fill in.
            On day 14, the ecosystem was taken apart.  The temperature was ___ and the pH of the water was ____.  The Elodea plants were _______ (alive, green, starting to grow, brown, etc).  The sea snail shell was empty.  The guppy was dead.  The gravel was _____.  (other observations)  A picture of the final day of the ecosystem is attached as figure 2.
            A summary table of the observations is attached as table 1.

Sample discussion

            In this experiment, a self-contained ecosystem was created.  The plan was to create a balanced ecosystem in which the gases would exchange, through the process of photosynthesis and cellular respiration, since no air from the outside was exchanged.  Photosynthesis uses CO2 and releases O2 while cellular respiration uses O2 and releases CO2.  Only plants undergo photosynthesis and are needed to feed other members of the ecosystem, so more plants were added to keep the balance of gases and to have enough energy for the guppies and sea snails.  Guppies eat the Elodea plants and blood worms, and sea snails eat algae and Elodea plants.  Because the sea snails eat the algae, they keep the water clean.  In this experiment, the snails died early and there was no one to eat the algae, so the tank became cloudy with algae.
            More plants needed to be added to the ecosystem because there is a loss of energy as energy is transferred to another living thing.  In this experiment, the Elodea plants became brown and did not seem to be good for eating.  Also, the guppy and snail died, so no organisms were eating the Elodea. 
            There were errors that could have affected the ecosystem survival and affected our results.  When the guppy was added to the ecosystem, it dropped on the table before going into the bottle.  This may have caused stress and made it die quickly.  (If your bottle disappeared, say so.  Observations were made on our ecosystem on day 3, but on the next day, the bottle had disappeared.  Maybe another class took it by mistake, but no more observations were made using the original bottle.  The observations were taken from another group’s ecosystem from day 6 on.)  Can you think of other errors that could not be helped?  Temperature changes over the weekend?  Rainy days with no sunshine?

Sample Conclusion

            The hypothesis for the experiment was if the correct balance of abiotic and biotic factors were added to the bottle ecosystem, then the ecosystem would be able to survive.  In the experiment, the correct balance of biotic and abiotic factors were not added, so the organisms did not survive.  However, there were errors that might have contributed to the demise of the organisms.  These are (temperature changes, loss of the bottle, etc).
            If this experiment could be done again, there are changes that would help make it more successful and have more organisms being able to survive.  More plants should be added so that more energy and gas exchange can occur.  (Other things that you think would help make it better next time).
            Overall, in order to create a successful self-contained ecosystem, many things must be kept in mind, including having enough energy sources from producers and the correct exchange of gases.   Other things are  (………).