GENETICS

The concept of variation.

By the end of the lesson, the learner should be able to:


Define Genetics.
Define variation.

Exposition of new concepts.
Probing questions on some variations in human beings.
Observe some variations in human beings such as tongue rolling, finger prints, students? heights, etc.
Discussion on the concept of variation.

Ink pad, hand lenses, white paper.

KLB BK IV.
PP 1-2.

GENETICS

Discontinuous variation.
Continuous variation.
Causes of variation.
The chromosome.

By the end of the lesson, the learner should be able to:
Define discontinuous variation.
Define continuous variation.
Give examples of characteristics that show continuous variation.
Discuss causes of variation.
Describe the structure of chromosomes.

Observe some discontinuous variations in human beings such as tongue rolling, sex, blood groups, etc.
Discussion on the concept of discontinuous variation.
Class activity ; students measure and record their heights;
Plotting of frequency-height graph;
Analyzing the graph;
Discussion with probing questions.
Exposition of new concepts.
Discussion with probing questions.
Probing questions.
Discussion.

text book
Metre rules/ tape measure,
Graph papers

KLB BK IV.
P 3.
KLB BK IV.
P 4

GENETICS

Chromosomal behaviour during mitosis.
Chromosomal behaviour during meiosis.

By the end of the lesson, the learner should be able to:
Describe chromosomal behaviour during mitosis.
Describe chromosomal behaviour during meiosis.

Exposition;
Teacher demonstrations;
Drawing diagrams;
Detailed discussion.

Scissors,
Manilla papers, thread, cellotape.
Manilla papers, threads, cellotape.

KLB BK IV. PP 5-6

GENETICS

Genes and DNA.
DNA replication.
First law of heredity.

By the end of the lesson, the learner should be able to:
Describe the structure of genes and DNA.
Identify the role of DNA.
Describe DNA replication.
Explain the role of DNA in protein synthesis.
Describe Mendel?s experiments.
State Mendel?s first law.

Expository approach.
Exposition;
Drawing mRNA strands.
Exposition with explanations.

Chart- the double helix DNA.
text book

KLB BK IV. PP 7-8

GENETICS

Monohybrid inheritance.
Genetic crosses using a punnet square.

By the end of the lesson, the learner should be able to:
Define monohybrid inheritance.
Differentiate between genotype and phenotype.
Draw diagrams to show genetic crosses.
Show fusion of gametes using a punnet square.

Q/A to review Mendel?s first law.
Drawing diagrams to show genetic crosses.
Discussion with probing questions.
Completing a punnet square;
Brief discussion.

text book

KLB BK IV. PP 12-14

GENETICS

Ratios of phenotypes and genotypes.
Incomplete dominance.
Inheritance of ABO blood groups.
Inheritance of Rhesus factor.
Determining unknown genotypes.
Sex determination in man.

By the end of the lesson, the learner should be able to:
Explain the concept of probability in inheritance of characteristics.
Cite examples of incomplete dominance.
Illustrate incomplete dominance with diagrams.
Illustrate inheritance of blood groups with diagrams.
Describe inheritance of Rhesus factor.
Determine unknown genotypes using test crosses and selfing crosses.
Describe sex determination in man.

Q/A to review phenotypes and genotypes.
Simple experiments on probability.
Discussion.
Exposition;
Discussion;
Drawing diagrams.
Drawing diagrams;
Supervised practice on inheritance of blood groups.
Exposition;
Discussion.
Probing questions;
Drawing illustrative diagrams;

Beans of two different colours, beakers.
chart
chart
text book

KLB BK IV. PP 15-17
KLB BK IV. PP 21-22

GENETICS

Sex-linked genes and traits.
Non-disjunction.

By the end of the lesson, the learner should be able to:
Identify sex-linked traits in man.
Illustrate inheritance of sex-linked traits with diagrams.
Explain effects of non-disjunction as a chromosomal abnormality.

Probing questions;
Drawing illustrative diagrams;
Discussion.
Exposition of new concepts;

text book

KLB BK IV. PP 24-27

GENETICS

Gene mutation.
Disorders due to gene mutations.
Applications of genetics.

By the end of the lesson, the learner should be able to:
Differentiate between chromosomal and gene mutation.
Identify types of gene mutation.
Illustrate genetic disorders with diagrams.
Identify areas of practical application of genetics.

Q/A to review types of chromosomal mutation;
Using sequence models to show chromosomal mutations.
Discussion.
Discussion on albinism, sickle-cell anaemia, haemophilia, colour blindness.
Drawing illustrative diagrams.
Probing questions;
Open discussion;
Topic review.

Models to show Chromosomal mutations.
chart
text book,video

KLB BK IV. PP 33-35