SECTION 1 — DETAILED NOTES
Genetics – Some Basic Fundamentals
Introduction to Genetics
Genetics is the branch of biology that studies:
● Heredity – transfer of characteristics from parents to offspring
● Variation – differences seen among individuals of the same species
This chapter explains how traits such as height, eye colour, blood group, and certain diseases
are inherited.
Importance of Genetics
Genetics is useful in many fields of science and medicine.
Applications of Genetics
● Genetic Engineering:** changing genes to improve organisms
● Insulin Production: human insulin gene inserted into bacteria to produce insulin
● Helps in studying inherited diseases
● Useful in agriculture and medicine
Gregor Mendel – Father of Genetics
Gregor Mendel was an Austrian monk who discovered the basic laws of inheritance through
experiments on pea plants.
He explained that:
● offspring resemble their parents
● traits are passed through hereditary factors
● inheritance follows fixed patterns
, Why Mendel Chose Pea Plants
Mendel selected pea plants because:
1. They showed clear contrasting traits
2. Pure varieties were available
3. Self-pollination occurred naturally
4. Cross-pollination could be controlled easily
5. They had a short life cycle
Scientific name of garden pea:
● Pisum sativum
Character and Trait
Term Meaning Example
Characte A heritable feature Plant height
r
Trait Different form of a character Tall or dwarf
Contrasting Traits Studied by Mendel
Character Dominant Trait Recessive
Trait
Flower colour Purple White
Seed colour Yellow Green
Seed shape Round Wrinkled
Pod colour Green Yellow
Pod shape Inflated Constricted
Flower position Axillary Terminal
Genetics – Some Basic Fundamentals
Introduction to Genetics
Genetics is the branch of biology that studies:
● Heredity – transfer of characteristics from parents to offspring
● Variation – differences seen among individuals of the same species
This chapter explains how traits such as height, eye colour, blood group, and certain diseases
are inherited.
Importance of Genetics
Genetics is useful in many fields of science and medicine.
Applications of Genetics
● Genetic Engineering:** changing genes to improve organisms
● Insulin Production: human insulin gene inserted into bacteria to produce insulin
● Helps in studying inherited diseases
● Useful in agriculture and medicine
Gregor Mendel – Father of Genetics
Gregor Mendel was an Austrian monk who discovered the basic laws of inheritance through
experiments on pea plants.
He explained that:
● offspring resemble their parents
● traits are passed through hereditary factors
● inheritance follows fixed patterns
, Why Mendel Chose Pea Plants
Mendel selected pea plants because:
1. They showed clear contrasting traits
2. Pure varieties were available
3. Self-pollination occurred naturally
4. Cross-pollination could be controlled easily
5. They had a short life cycle
Scientific name of garden pea:
● Pisum sativum
Character and Trait
Term Meaning Example
Characte A heritable feature Plant height
r
Trait Different form of a character Tall or dwarf
Contrasting Traits Studied by Mendel
Character Dominant Trait Recessive
Trait
Flower colour Purple White
Seed colour Yellow Green
Seed shape Round Wrinkled
Pod colour Green Yellow
Pod shape Inflated Constricted
Flower position Axillary Terminal
