The Fundamentals of DNA, Genetics, and Biotechnology

The Structure of DNA and the Human Genome

In 1953, James Watson and Francis Crick established the molecular structure of DNA. The genetic information of a living organism's cells is stored in chromosomes. The complete set of this genetic information is called the genome.

The Human Genome

The human genome sequence was published in 2003. It consists of 23 pairs of chromosomes and contains approximately 20,000 protein-coding genes. These genes make up only about 2% of the entire genome. The remaining 98% of the DNA, which includes introns, is non-coding. This portion was once referred to as "junk DNA," but its functions are still being studied.

DNA Composition

DNA is a molecule composed of two chains, forming a double helix. Each chain is made of many chemical compounds called nucleotides. The components of a nucleotide are:

• Nitrogenous Bases: Adenine (A), Thymine (T), Guanine (G), and Cytosine (C).
• A Sugar: Deoxyribose.
• Phosphoric Acid.

Core Concepts in Genetics

Genes and Genotype

Genes are fragments of DNA that carry information for specific traits. An individual's complete set of genes is their genotype.

The Process of DNA Duplication

DNA duplication, or replication, is the process by which the genetic message is copied, allowing it to be transmitted from parents to their children.

The Value of Genes

The significance of a gene lies in its ability to replicate for reproduction and transmit hereditary information. Genes also provide instructions for building proteins, which carry out most functions in living creatures.

Cloning and Biotechnology

Body and Plant Cloning

Body cloning is the process of creating a genetically identical copy of an organism. A clone is a group of individuals or cells descended from a single ancestor through asexual reproduction, making them genetically identical.

Plant cloning does not always require genetic engineering technology. A traditional method is cloning from cuttings (aldaxken).

Transgenic Organisms

Transgenic organisms are genetically modified organisms (GMOs). They contain DNA from another species and are capable of reproduction. Genetically modifying prokaryotes, plants, and animals is becoming more common, allowing for the production of interesting proteins and the expression of new traits.

Applications in Transgenic Plants

• Protection against pests and diseases.
• Resistance to herbicides.
• Improved fruit quality.
• Increased tolerance to harsh environmental conditions.
• Production of biofuels.

Applications in Transgenic Animals

• Producing medicines in the milk of sheep, goats, and cattle.
• Developing animals with better features, such as less fat or faster growth.
• Studying human diseases by inserting human genes to find cures.

Understanding Stem Cells

Stem cells are undifferentiated cells that have the potential to develop into many different types of tissues and cells in the body.

Types of Stem Cells

• Embryonic Stem Cells: Derived from leftover embryos from in vitro fertilization (raises ethical concerns).
• Adult Stem Cells: Found in tissues like the umbilical cord or bone marrow.
• Induced Pluripotent Stem Cells (iPSCs): Created by reprogramming differentiated adult cells (like neurons) back to a stem-cell-like state.