Lesson Plan

Topic: Chromosomes

Class: 9^th Standard

Subject: Science

Teacher : Good Morning, Students

Pupil : Good Morning, Madam

Teacher : Dear Students, what is this? (Teacher shows the chain made up of beads)

Pupil : It is a chain

Teacher : What it is made up of?

Pupil : It is made up of beads

Teacher : Good. Now, how it looks like? (Teacher folded the chain unevenly and kept in a round box)

Pupil : It looks like a snake inside the cage

Pupil : It looks like a rope in the box

(From the faces of pupil, teacher observes that pupil are interested and from their answer, she understood that the examples are simple)

Teacher : Good. Today we are going to learn about the Chromosomes which is seen inside the Nucleus. (The Pupil infer the shape of chromosomes)

Like the pith portion in the sugarcane, chromosome can separate itself into two halves called Chromatids. When separate, both sister chromatids remain attached to each other at the Centromere, also known as the Kinetochore

(Teacher took the China clay and make the chromatids and centromere and shows to the children)

(Teacher uses non-verbal media)

Children what did you observe from this?

Pupil : Four equal arms attached to the one centromere as such in ceiling fan

Teacher : Yes. The chromatids are equal in size. Now, let us learn how the chromosomes are grouped based on the location of the centromere.

(Teacher break the chalk piece into equal halves and keep it in ‘V’ shape )

How it is looking?

Pupil : It looks like a capital letter ‘V’

Pupil : Two equal lines joined at one end and open at the other end

Teacher : Good. This type is called as Metacentric Chromosome.

How will be the capital letter ‘J’ look like?

(Teacher took the China clay and makes the chromatids and centromere in ‘J’ shape and shows to the children)

(Teacher uses non-verbal media)

Pupil : A straight line bends at the edge

Teacher : Pupil can you give some examples for this shape? (Teacher elicits examples from pupils for verification) (Pupil raise their hands)

Pupil : Just like an umbrella stick

Pupil : Like an inverted walking stick

Teacher : Very Good. The length of one chromatid is long and another is short and both are attached by the centromere and this type is called as Submetacentric

Chromosome. Let us assume there are two unequal rods. They are joined by a clamp one above the other, lengthy one below and shorter one above. How it will be?

Pupil : It looks like a straight lengthy rod

Pupil : Like two unequal PVC pipes joined by a clamp

Pupil : Like the pen and its cap

Teacher : Good. It is called as Acrocentric chromosome. Next we assume a stick with a crystal head or knob. How it will be?

Pupil : Like a pencil with eraser

Pupil : Like a curd stirrer

Pupil : Like a butterfly head and body

Teacher : Very good. It is called as Telocentric Chromosome. So we learn the four types of chromosomes based on the centromere. Can you recall the types of chromosomes?

Pupil : Metacentric, Submetacentric, Acrocentric and Telocentric Chromosomes

Teacher : Very good. Thank you, students.