Chromosomes, DNA, Genetic Engineering, and Biotechnology
Chromosomes
The number of chromosomes in a species remains constant. During the formation of sexual cells, the parents do not merely halve the number and rather carry 2 copies of each chromosome, only one is passed on.
Karyotype
Set of ordered chromosomes.
DNA
Whitish substance. Its chains form a double helix. Each chain is formed by phosphate groups, sugars, and nitrogenous bases: adenine, guanine, cytosine, and thymine.
Genes
A DNA fragment that contains the necessary information to synthesize a protein.
RNA
Substance that is able to move beyond the nucleus with instructions to directly synthesize proteins.
Genetic Code
Each group of three consecutive bases defines and allows the production of a different amino acid.
Mutations
Alterations in the order of the nucleobases in DNA.
Proteins
Chains of very large molecules that are the principal substances that compose our body and all other organisms.
Genetic Engineering
Techniques aimed at transplanting genes between living species.
Antibiotics
Substances manufactured by bacteria that prevent the growth of other bacteria and fungi.
Transgenic Organisms
Organisms genetically modified.
Transgenic Plants
In Spain, a transgenic maize variety resistant to the attack of corn borers is being cultivated. A gene from a bacterium capable of making a substance poisonous to the borers is incorporated into the maize genome.
Transgenic Animals
The genome of giant salmon contains two genes: one that does not interrupt growth during winter and another that does not stop building the growth hormone of the fish when it reaches maturity.
Transgenic Microorganisms
A gene for a human protein (insulin) was introduced into the DNA of bacteria, and it was achieved that this bacteria makes insulin.
Biotechnology
Utilization of living organisms for commercial purposes. It encompasses products in the food industry, pharmaceutical industry, agriculture and livestock, environment, and medical research.
Risks of Biotechnology
Loss of genetic diversity, the accidental ‘jump’ of transferred genes to other wild species or traditional crops, and potentially harmful effects on health.
Gene Therapy
Use of genes for the cure or palliative treatment of diseases, both inherited and acquired.
Prenatal Diagnosis
Early diagnosis within the uterus of certain genetic diseases.
Preimplantation Diagnosis
Diagnosis of the embryo before being implanted.
Genome
Set of all genes of a living being.
Genetic Fingerprints
A long DNA sequence of 3 billion letters only coincides exactly with that of an identical twin or a clone.
Applications of Genetic Fingerprints
- Paternity Tests: A comparison of the genetic markers of the mother, son/daughter, and possible fathers. The band contains a number that belongs to the mother and the rest to the father.
- Criminal Investigations: The genetic fingerprint obtained from a sample found at the crime scene is compared with the fingerprints of the suspects. The goal is to see if the bands of the drawing of the sample found at the crime scene match that of a suspect.
Cloning
The nucleus of an egg is removed, and a nucleus from a body cell is implanted. The nucleus of the body cell is then implanted inside the egg, which divides into four and leads to a blastocyst. The blastocyst is then cultivated *in vitro* to obtain stem cells, and finally, adequate resources are provided for their differentiation.
Stem Cells
A body cell that is not specialized in any function, that can multiply, and that is capable of becoming any of the more than 200 cell types of an adult.
Types of Stem Cells
- Totipotent: Stem cells that can lead to a complete organism.
- Pluripotent: They generate cells of any tissue.
- Multipotent: Cells that only create cells of a specific tissue.
- Embryonic Stem Cells from Surplus Embryos from In Vitro Fertilization Processes: They proceed from the inner mass of a blastocyst about 5-7 days old. They are the ones that have the greatest pluripotent potential and can cause any type of tissue.
- Embryonic Stem Cells from Nuclear Transfer Process: Allowing therapeutic cloning to clone a few cells of the patient. These transplanted cells would not carry the risk of rejection.
- Adult Stem Cells: They are multipotent and are found in all human tissues, although not in the same proportion.
- Induced Pluripotent Stem Cells: Specialized adult cells that, after being subjected to different treatments, dedifferentiate and transform back into pluripotent embryonic stem cells.