GENETICS

The concept of variation.
Discontinuous variation.
Continuous variation.
Causes of variation.
The chromosome.
Chromosomal behaviour during mitosis.
Chromosomal behaviour during meiosis.
Genes and DNA.
DNA replication.
First law of heredity.
Monohybrid inheritance.
Genetic crosses using a punnet square.
Ratios of phenotypes and genotypes.
Incomplete dominance.
Inheritance of ABO blood groups.
Inheritance of Rhesus factor.
Determining unknown genotypes.
Sex determination in man.
Sex-linked genes and traits.
Non-disjunction.
Gene mutation.
Disorders due to gene mutations.
Applications of genetics.

By the end of the lesson, the learner should be able to:
Define Genetics.
Define variation.
Define discontinuous variation.
Define continuous variation.
Give examples of characteristics that show continuous variation.
Discuss causes of variation.
Describe the structure of chromosomes.
Describe chromosomal behaviour during mitosis.
Describe chromosomal behaviour during meiosis.
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.
Define monohybrid inheritance.
Differentiate between genotype and phenotype.
Draw diagrams to show genetic crosses.
Show fusion of gametes using a punnet square.
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.
Identify sex-linked traits in man.
Illustrate inheritance of sex-linked traits with diagrams.
Explain effects of non-disjunction as a chromosomal abnormality.
Differentiate between chromosomal and gene mutation.
Identify types of gene mutation.
Illustrate genetic disorders with diagrams.
Identify areas of practical application of genetics.

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.
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.
Probing questions.
Discussion.
Exposition;
Teacher demonstrations;
Drawing diagrams;
Detailed discussion.
Expository approach.
Drawing mRNA strands.
Exposition with explanations.
Q/A to review Mendel?s first law.
Drawing diagrams to show genetic crosses.
Completing a punnet square;
Brief discussion.
Q/A to review phenotypes and genotypes.
Simple experiments on probability.
Discussion;
Drawing diagrams.
Supervised practice on inheritance of blood groups.
Probing questions;
Drawing illustrative diagrams;
Exposition of new concepts;
Q/A to review types of chromosomal mutation;
Using sequence models to show chromosomal mutations.
Discussion on albinism, sickle-cell anaemia, haemophilia, colour blindness.
Drawing illustrative diagrams.
Open discussion;
Topic review.

Ink pad, hand lenses, white paper.
text book
Metre rules/ tape measure,
Graph papers
Scissors,
Manilla papers, thread, cellotape.
Manilla papers, threads, cellotape.
Chart- the double helix DNA.
Beans of two different colours, beakers.
chart
Models to show Chromosomal mutations.
text book,video

KLB BK IV.
PP 1-2.