Demonstration-An Effective Technique In Teaching Biology (jnrlse)

Demonstration Room

The demonstrations are set up in a room designed specifically for this purpose (Fig. l). Display cases have been installed along three walls of the room and a black- board and screen are located on the fourth wall. Be-

Table 2. The objectives, and headings of displays in a

demonstration on “Adaptation in Organisms”t
Contents of a Display

Each display consists of a visual presentation through the use of charts, tables, illustrations, and live or dried material (Fig. 2). Some organisms such as fish, small rodents, birds, and plants are ideal for use as live dis- plays to illustrate principles such as organismal diversi- ty, ecological isolation, covergence, competitive exclu- sion, etc. Students are provided with a written outline that explains the main points of the display (Box l). The data presented are a synthesis of results from one or more research articles. Often the research article is simplified to make it more easily understandable for a student. Scientific jargon is clarified and only salient points from tables and graphs are presented. The written explanation of a display consists of one or two questions which allows a student to think critically. Some displays in a demonstration may be supplemented

Objectives
Film
Display I .


Display 2.


Display 3.

Display 4. Display S. Display 6.

Display 7.
Display 8.
Display 9.
To show a) adaptive value of some external characters of animals and plants, and b) variation among different individuals of a species in one area.
Patterns for survival—shows cryptic coloration, warning colora- tion, Batesian mimicry, Mullerian mimicry, frightening colora- tion, and confusion syndrome.
Adaptation to physical environment; roadrunner (Geococc yx californianus).
Cryptic coloration and patterns; peppered moth (Breton betularia).
Energetics or crypsis? Eastern gray squirrel (Scrums carolinensis).
Warning coloration; monarch butter fly (Danaus plexippus).
False warning coloration; viceroy butterfiy (Limenitis archippus).
Geographic variation of an adaptation; viceroy butterfly and queen butterfly (Danas gilippus).
Mimicry in plants; Orchids and hymenopteran insects. Mimicry of vertebrate eyes; peacock butterfiy (Inachis to). Sexual dimorphism and sec recognition; common flicker
(Colaptus auraius).
Fig. 1. A general view of the demonstration room. Dis- play cases are installed along the three walls of the

This demonstration was written by Dr. D. M. Scott, professor, Dep. of Zoolo- gy who gives lectures in ’‘Biology of Populations”.
room. Blackboard and a movie screen are on the fourth wall (not seen in the picture).

by computerized instruction, slides, and films pertain- ternate weeks. The teacher-student ratio is 1:30 and a ing to the topic. Simple computer programs such as student meets with the instructor once every 2 weeks for human population growth, diversity, and stability of 3 hours for the whole academic session.
populations are available. The course has three com- If a student feels he knows the concept well enough puter terminals. The instructor provides information on and could use his time more efficiently elsewhere, he how to run a program and students take turns to see, for

example, growth of populations with different intrinsic growth rates. Slides are illustrated by slide synchs and narrated with tapes made by the instructor lecturing in the course.


Operation

The demonstration room is open from 8:30 to 5:30

p.m. Monday to Thursday. Students are free to come any time, but the instructors are present from 8:30 to 11:30 a.m. and 2:30 to 5:30 p.m. each day. The course includes formal lectures, demonstrations, and labs. Demonstrations are alternated weekly with labs (Table 3). Students come to the demonstration and labs in al-
Table 3. Schedule of lab and demonstration sessions (16 sections of 30 students each) during a
5•day work week



Afternoon



8:30-I I:30 a.m. 2:30-5:30 p. m.

	Lab?	Demonstration t		Labt	Demonstration t
Monday Tuesday Wednesday Thursday	S-1 S-3 S-5 S-7	S-9 S-11 S-13 S-15		S-2 S-4 S-6 S-8	S-10 S- 12 S-14 S-16

Friday Change of a lab or demonstration.
Preparatory meetings of instructors for discussion of a lab or demonstration.

i Students attending a lab this week will go to the demonstrations next week and

Fig. 2. A display on farm productivity and energy crisis.

need not attend the demonstration. In the demonstra- tion room students proceed at their own pace, repeating a display which illustrates a difficult concept as often as necessary. If a student's concentration is poor, he can take a break, leave, or return the next day. Since it is his own time, it is to his advantage to use it well.
If a student is unable to answer a question, he usually discusses it with peers or the instructor. About one-half hour before the end of a demonstration period (11:00
a. m. or 5:00 p.m.), the instructor brings the students to- gether and asks questions about any difficulties en- countered in the displays and provides answers to ques- tions in the handout. Students are tested on the material in the demonstrations with written examinations.
To ensure uniformity of instruction, a preparatory meeting of all instructors is held. Each display is re- viewed and every question is discussed thoroughly.