Fundamentals of Genetics: DNA, Proteins, and Applications
What is Genetics?
The unit of inheritance is called a gene. Genes are transmitted according to defined rules or laws. They are located on chromosomes, structures composed of a substance in the cell nucleus. Sex is determined by genes or chromosomes in most living organisms.
Key Genetic Terms:
- Genotype: Genetic constitution of an individual character or a whole set of genes.
- Phenotype: The external expression characteristic of the individual.
- Alleles: Each variant of a gene. For each gene, an individual
Cell Structure: From Theory to Chromosomes
1.1. The Cell Theory
Thanks to Schleiden and Schwann, the development of cell theory began:
• The cell is the structural unit of all living things.
• It is the functional unit that performs all life processes.
• Every cell comes from an existing one.
• It represents the genetic unity of all living things, containing the hereditary material passed to daughter cells.
3.1. Prokaryotic Cell Structure
• Cell wall: a rigid casing formed by polysaccharides and proteins that give shape to bacteria.
Read MoreChromatin, Chromosomes, and Cell Membranes: Structure and Function
Chromatin and Chromosomes
Chromosomes are composed of DNA and proteins, forming the complex called chromatin.
Genetic Components
- Genes: Determine individual characteristics.
- Genome: A complete set of DNA containing information to synthesize proteins (approximately 30,000).
- Karyotype: An ordered arrangement of chromosomes.
- Homologous Chromosomes: One pair of parental and one paternal chromosome.
Chromosome Structure
A chromosome consists primarily of centromeres. Types include:
- Metacentric: Centromere in
Human Excretory System: Function, Organs, and Diseases
Excretion
Excretion is the expulsion of toxic substances from the blood. These substances are products of cellular metabolism (urea, uric acid, and carbon dioxide) and ingested salts. Its purpose is to remove harmful substances from the blood and maintain a constant concentration of dissolved salts.
Harmful substances:
- Urea: main substance derived from ammonia, formed in the metabolism of proteins. Ammonia is transformed into less toxic urea.
- Uric acid: A substance derived from ammonia.
- Dissolved minerals:
Understanding AIDS, Renal Pathophysiology, and Metabolic Stress
AIDS and HIV Infection
What is AIDS?
AIDS, a disease caused by HIV, manifests after infection with the human immunodeficiency virus (HIV).
- Syndrome: A group of signs and symptoms characterizing a disease.
- Immunodeficiency: The body’s inability to defend against microorganisms.
- Acquired: Unlike other immunodeficiencies, AIDS is not congenital but caused by an external factor.
Etiologic Agent: HIV
HIV is a retrovirus (an RNA virus that replicates via a DNA intermediate). It’s fragile and easily inactivated
Read MoreCell Biology: History, Structure, and Organization
Cell Biology: A Comprehensive Study
History of Cell Biology
Robert Hooke (first to observe cells in cork), Robert Brown (discovered the cell nucleus), Purkinje (coined the term protoplasm), and Schwann and Schleiden (*Cell Theory*).
Cell Structure and Organization
Theme
Cells exhibit diverse shapes: star-shaped, elongated, cylindrical, etc.
Size
Cell size varies greatly; most are microscopic. Measurement units include microns and Angstroms.
Organization
Prokaryotic cells (bacteria): Organelles lack membrane-
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