This project involves the construction of genetic model using cheap and easily accessible materials to explain various laws in genetics, crosses and heredity.

(a) This genetic model aims to help students visualise the genetic terms and Laws.

(b) This genetic model aims to attract the attention of students studying genetics.

(c) This model allows students to have a hand on experience in learning genetics as well as allowing more interaction between teacher and students and among students.

(d) This model allows students to predict the outcome of crosses involving individuals with different genotypes and phenotypes.

• This genetic model will help students understand various genetic concepts.
• This genetic model allows students to visualise various genetic terms such as genes, chromosomes, phenotypes, genotypes, heterozygous and homozygous as well as the process of inheritance.
• The suitability of the materials used makes the model easy to be transferred, used and even displayed on the board.
• This model can be used to teach a wide range of subtopics from genetic definitions to genetic laws.
• Finally this model will make teaching and learning genetics fun and stimulates students' imagination.

(a) 10 paper plates (about 20 cm diameter).The upper surface of the plate represents Genny's cell on which the chromosomes are placed. The underside of the paper plate represents the different phenotypes of Genny i.e. his physical characteristics.

(b) 20 ice cream sticks to represent chromosomes.

(c) Red and yellow stickers to represent genes on the chromosomes.The red stickers represent dominant gene for red fur colour.The yellow stickers represent recessive gene for yellow fur colour.

 

(a) Paint the rims of the upper surface of 6 paper plates with red colour and the rims of four other plates with yellow colour. The red plates will be used more often than the yellow ones. The red-rimmed plates represent red fur Genny. The yellow-rimmed plates represent yellow fur Genny (diagram 8-D1).

(b) Stick 10 red stickers on ten of the ice- cream sticks. Label the stickers with 'R' to represent red gene.

(c) Stick 10 yellow stickers on another 10 ice-cream sticks at the same location as the red stickers. Label the stickers with 'r' to represent yellow gene (8-D2).

(d) Finally, to prepare the different phenotypes of the genetic model, Genny, paint the underside of the 4 plates as shown in 8-D3. These designs are made to show two unusual characters i.e. fur colour (red or yellow) and type of antenna (erect and droopy). Hence we have our colourful helpful and interesting pet…Genny rotundus. (8-D3).

(e) The four-phenotype plates are to be displayed on the board by the teacher and need not be given to the student groups.

A. First lesson: Teaching genetic terms.

(a) The teacher tells the class that she has "cultured" a special organism named Genny to be used in learning genetics.

(b) The teacher takes out the phenotype plates. The teacher shows the red and yellow Genny with erect antenna to the class. (The ones with droopy antenna will be introduced when teaching dihybrid cross which involves two different characters)..

(c) The teacher must also explain to the students that the colour of the fur is determined by a pair of genes found on a pair of chromosomes in Genny's cell.
At this point flip over the plate to show the upper surface with two ice-cream sticks and stickers on them. The sticks can be taped or glued to this plate.

(d) The teacher explains that the underside of the plate represents Genny's physical appearance while the upper surface represents its cell. The sticks represent the chromosomes and the stickers represent the genes.

(e) The plates and sticks are then distributed to the students.

(f) Handouts on genetic terms and definitions can also be distributed.

(g) As the teacher introduces the genetic terms and definitions, she asks the students to identify and combine the materials to represent or depict the various terms (as in 8-D4).

(h) Finally, correct representations suggested by the students are displayed on the blackboard under the various genetic terms. This gives the students an overview of the terms learnt.

B. Second Lesson: Teaching Monohybrid Cross

(a) The teacher ask the students to predict the phenotypes and genotypes of the offspring from a cross between a pure bred red fur Genny with a pure bred yellow fur Genny.

(b) The teacher writes the words such as parent, gamete, genotype and phenotype of the offspring on the left column of the board.

(c) The teacher then invites suggestions from the students for the genotypes of the gamete as well as the phenotypes of the parents, and offspring.

(d) The right representations are taped on the board as in 8-D5 (A).

(e) The teacher then asks the students for the results of a cross between two heterozygous Gennys. Step (c) and (d) are repeated.

(f) Diagrams of the crosses are introduced at the end of this lesson.

C. Third lesson: Teaching Dihybrid Cross

(a) For this lesson the teacher needs to prepare another set of shorter ice-cream sticks. The same type of ice-cream stick is used, but they are cut shorter with a pair of scissors. Stickers of two other colours are stuck on these short sticks to depict genes that determine the type of antenna. The genes are labelled E (erect gene) or e (droopy gene) (8-D6).

(b) The teacher explains the meaning of dihybrid cross.

(c) The teacher shows the students another characteristic of Genny (erect or droopy antenna). The four-phenotype plates (8-D3) are shown. The erect antenna gene is dominant while the droopy antenna gene is recessive.

(d) The teacher then ask the students to predict the outcome of a cross between a pure bred red fur, erect antenna Genny and a pure bred yellow fur, droopy antenna Genny.
Students then try out the cross with their materials (8-D5 (B)).

This model could be made more interesting if it is integrated with cooperative learning teaching strategies with emphasis on the principles such as positive interdependence (e.g. sharing of resources and assigning roles) and individual accountability in conceptual approach (Learning Together).

Apart from that, active learning with more examples given on monohybrid/ dihybrid cross could be carried out if the resources that are easily accessible or prepared could be used, e.g. colourful seeds, to replace ice cream sticks.