Understanding Genes, DNA, and Inheritance môn Principle of Management | Trường Đại học Quốc tế, Đại học Quốc gia Thành phố Hồ Chí Minh

Introduction to Genetics
Genetics is the branch of biology that studies genes, genetic variation, and heredity in living organisms.
It seeks to understand how traits are passed from parents to offspring and how genetic
information is expressed and regulated.
1. The Concept of Genes
A gene is a segment of DNA that contains the instructions for building a specific protein or RNA molecule.
Genes are located on chromosomes within the cell nucleus. Each gene has a specific
position, called a locus, on a chromosome.
2. DNA and Chromosomes
DNA (deoxyribonucleic acid) is a double-stranded molecule that carries genetic information.
It consists of four nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G).
The sequence of these bases determines the genetic code.
Chromosomes are long DNA molecules coiled around proteins called histones. Humans have
46 chromosomes arranged in 23 pairs.
3. Mendelian Genetics
Gregor Mendel, the father of genetics, discovered the basic laws of inheritance through experiments with pea plants.
He proposed that traits are controlled by pairs of alleles, one inherited from each parent.
4. Types of Inheritance
- **Dominant and Recessive Inheritance:** Dominant alleles mask the expression of recessive alleles.
- **Incomplete Dominance:** The heterozygous phenotype is intermediate between the two homozygous phenotypes.
- **Codominance:** Both alleles are equally expressed (e.g., AB blood type).
- **Polygenic Inheritance:** Traits controlled by multiple genes (e.g., skin color, height).
5. Molecular Genetics
Molecular genetics studies the structure and function of genes at a molecular level.
It includes processes such as DNA replication, transcription, and translation.
6. Genetic Mutations
A mutation is a change in the DNA sequence. Mutations can occur spontaneously or be
induced by external factors such as radiation or chemicals.
Some mutations are harmless, while others can cause genetic disorders.
7. Applications of Genetics
Modern genetics has numerous applications, including:
- Genetic engineering and biotechnology
- DNA fingerprinting and forensic science - Gene therapy
- Understanding evolution and biodiversity
Genetics continues to evolve as technology advances, deepening our understanding of life and heredity.