Fundamentals of Genetics and Modern Applications
Core Concepts in Genetics
Genetics studies everything related to biological inheritance, genes, and their expression in organisms.
Conclusions from Classical Genetics:
- The unit of heredity is the gene.
- Genes are transmitted according to defined rules or laws.
- Genes are located on chromosomes.
- Sex is determined by genes or chromosomes.
Key Genetic Terms
Genotype: The genetic constitution of an individual character or refers to a whole set of genes.
Phenotype: The outward expression of the genotype.
Allele: One of the variants that genes have; for each gene, there are typically two alleles.
Homozygous: An individual who has two identical alleles for a particular gene.
Heterozygous: An individual having two different alleles for a particular gene.
Locus: The actual site on the chromosome where each gene is located.
DNA (Deoxyribonucleic Acid): A molecule enclosed in the nucleus (in eukaryotic cells) that contains all the genetic information, like a library holding instructions to develop the basic characteristics of the individual.
Genetic Code: The correspondence between the nucleotides (in DNA or RNA) and amino acids in proteins; it is universal across most organisms.
Genetic Engineering and Organisms
Transgenic Organisms: These are developed from a cell by introducing a DNA fragment from another living being, which integrates into its genome. When referring to viruses or bacteria modified this way, they are called recombinant organisms.
Applications of Genetic Engineering
- Pharmaceutical Production: Creating medicines using genetically modified organisms.
- Gene Therapy: Treatment of a disease based on introducing genes into the body, often using a vector like a virus.
- Agricultural Applications: Developing crops with enhanced traits (e.g., pest resistance, higher yield).
- Environmental Applications:
- Bioremediation: Using bacteria and mold created to biodegrade pollutants like oil spills.
- Biosorption: Creating bacteria capable of absorbing metals from surfaces or solutions.
Assisted Reproductive Procedures
Artificial Insemination (AI): Involves introducing semen into the uterus through a cannula. Semen can be from the male partner or a donation from a sperm bank if the partner is infertile.
In Vitro Fertilization (IVF): Consists of fertilization in the laboratory, followed by implanting the embryo(s) into the mother’s uterus. Typically, 2 or 3 embryos may be implanted. Others can be conserved (frozen) for future attempts if the first implantation fails or if the couple wishes for more children. When semen quality is low, Intracytoplasmic Sperm Injection (ICSI) is often used.
Cloning Techniques and Applications
Single Cell or Tissue Cloning: Can be utilized for patient medical purposes or research. These involve stem cells (undifferentiated cells that can develop into a specific tissue or organ). The most utilized are pluripotent stem cells, which can give rise to any cell or tissue type.
Organ or Reproductive Cloning: The process of obtaining an animal or plant organism genetically identical to another. This is done in two main ways: by inducing divisions in an embryo or by nuclear transfer (requiring a donor cell and a recipient egg cell). The objective can be to obtain totipotent cells.
Applications of Cloning
Cloning applications include research in various fields, reproduction of transgenic animals, breeding endangered species, and therapeutic uses.
Bioethics in Life Sciences
Bioethics: The application of ethics to the life sciences, addressing moral issues arising from advances in biology and medicine.