USE OF COMMON ORGANISMS IN THE SCIENCE CLASS

Mississippi Science Teachers Association

October 29, 2012

Using common organisms in the science classroom can:

• Enable students to participate in “real science”• Result in individual observations and follow-up

experimentation• Participate in real inquiry• Formulate and write hypotheses and

procedures• Use graphic or chart forms• Draw conclusions

Other benefits include:

• Gathering data• Recording results• Identifying variables• Carrying out original research and “doing” real

science

Some suggestions for use of common organisms include:

• Use of common land snails to measure the amount of lettuce they consume in a 24 hour period (study of metabolism).

• Study of the effect of garlic on the growth rate of grass seeds (allelopathy). Allelopathy is a biological phenomenon by which an organism produces one or more biochemicals that influence the growth, survival, and reproduction of other organisms.

Ants

• Study of ant colonies can be carried out in the schoolyard by working in groups of 2-3 students, writing 5-10 observations about ants and their behaviors. Questions to consider include: how often ants go out from the ant hill, how far do they travel, and do they act differently in the sun as opposed to the shade?

Further studies can be carried out indoors:

• Dig up a portion of the ant hill and place the contents in a large pan or bucket. Remove the neck and shoulder of a clear 2-liter bottle and spoon a quantity of ants and dirt inside. Spread a collar of vaseline around the outside edge of the opening to help prevent the ants from escaping. Cover the outside of the container with black construction paper held in place by rubber bands to simulate darkness. The ants will create tunnels along the outer walls, visible when the black paper is removed.

After spending a week of observation:

• Students should return the ants to the area from which they were removed.

Bees

Bees

• May be collected in the field, • Obtained from beekeepers, or• Ordered from science supply houses.• They may be stored in a freezer until needed.

Place a frozen specimen in a Petri dish and:

• Ask students to write 10 observations of bees, noting that bees have 6 legs, 4 wings, compound eyes, antennae, hairy bodies, jointed legs, claws at the end of the legs, and 3 body divisions (head, thorax, and abdomen).

• Have students share their observations and read resource information about bees. Make sure all students have observed the same structures.

Students should look for specific structures such as:

• Antenna cleaner• Hooks on the wings• The pollen brush• The stinger• The auricle• The pollen basket• Encourage students to formulate a hypothesis

for the function of each structure.

Ask students to then design their own experiment with bees:

• They should use scientific methodology.• They might investigate the color and/or height of flowers more

frequented by bees as they move about a flower bed.• Record how many bees come to a sugar dish in a specific time period.• Students could gather data over a week and then share results on

Friday. • Extension activities on their observations might be explored such as

honey color being determined by types of flowers nectar is obtained from.

• Research the decreases in bee populations that have resulted from viral infections.

• Research the economic impact that bees have due to their pollination activities.

Grasses

Grasses

• Grasses cover almost 1/3 of the land area of the Earth and ½ of the area of the United States. However, textbooks give little attention to this important group of plants.

• Grasses and cereals, including wheat, barley, rice, and corn provide much of the world’s food supply. They help to hold soil together and prevent erosion. Cane sugar, starch, alcohol, and other products are derived from grasses

Grasses with their flowers:

• Can be collected in all seasons of the year.• There are over 3,000 species of grasses grown

in the U. S.• A given U. S. locality may have up to 75-100

species of grasses.

Ask students to:

• Observe where grasses grow• Write 5 conclusions from study of each grass• Research grasses in resource books or on the

Internet• Categorize grasses by the season in which they

grow and flower• Describe the type of influoresence, the ligule,

the presence of the auricle, and the grass flower.

Discussion topics might include:

• The value of hybrid corn and how it is obtained

• The concept of monocultures in a lawn or field• How to rid an area of some annual grasses

such as foxtail and crabgrass.• Genetic experimentation involving grass

species.

Follow-up activities might focus on:

• Seed viability• The effect of different fertilizers on grass• How best to grow grasses.

Snakes

Native Species of Snakes

• Many people believe that “the only good snake is a dead snake”. Our students should be educated on the value of native species in ecosystems and food chains of nature. They should also become familiar with native species that are venomous.

Students could be assigned:

• The task of researching the native species that are most prevalent in a particular area of our state and what their specific role is in the ecosystem is.

• What type of reproduction the snake carries out.• Becoming familiar with the anatomy of the typical

snake.• Describing how snakes eat and their specific diets.• Which species are endangered or nearing extinction.• Which venomous species occur in their area of the state

and how venomous snake bites are treated.

Study of common organisms helps students:

• Develop observational and inquiry skills• Build a practical working knowledge of

scientific methods and of current technology• Gain a better understanding of many basic

science concepts and theories.

From these experiences students learn:

• To interpret their experiments and to document them

• Communicate their results in narratives or through PowerPoint presentations.

• This type of “natural science” is also helpful in helping us achieve the National Science Standards.

Reference:

• Carolina Tips, Using Common Organisms, Carolina Biological Supply Company