Genetic Engineering and Biotechnology: A Comprehensive Overview

Posted on Oct 27, 2024 in Geology

1. DNA

DNA molecules are made up of nucleotides. Each nucleotide contains one of four bases: adenine (A), thymine (T), cytosine (C), and guanine (G). These bases pair in a specific way: A with T, and C with G. These pairings create complementary strands.

2. Genetic Engineering

Genetic engineering is the technology of manipulating and transferring DNA from one organism to another. This technology allows for the creation of new species, the correction of genetic defects, and the production of various compounds.

Transgenic Plants

An example of genetic engineering in plants is transgenic maize grown in Spain. This maize is resistant to stem borers because a bacterial gene producing a toxin lethal to the larvae has been incorporated into the maize genome.

Transgenic Animals

The first transgenic animal patented for human consumption is a salmon. This salmon grows eight times faster than non-transgenic salmon due to the introduction of genes that promote continuous growth, even in winter.

Organism Example

Another example is the production of insulin. The human insulin gene is inserted into the DNA of bacteria, enabling the bacteria to produce insulin.

3. Enzymes

Enzymes are biocatalysts—molecules that accelerate chemical transformations within cells. They bind to the substance they will transform, facilitating the process.

4. Genetically Modified Organisms

A genetically modified (GM) organism is one whose genetic material (genome) has been altered by the artificial introduction of a foreign gene through genetic engineering.

Cycle of Creating Transgenic Organisms

  1. DNA containing the desired gene is extracted from a cell.
  2. The gene is isolated by cutting the DNA at precise locations.
  3. The gene is cloned.
  4. The gene is modified, often by adding exogenous gene fragments to facilitate further processing.
  5. The transgene is introduced into the nucleus of the target organism.
  6. Scientists verify that the transgene is capable of expressing the desired information.

Transgene

A transgene is a gene introduced into a genome by genetic engineering.

5. Biotechnology

Biotechnology is technology based on biology, particularly used in agriculture, pharmacy, food science, environmental science, and medicine.

Risks of Biotechnology

Risks associated with biotechnology include loss of genetic diversity and potential adverse effects on health.

6. Human Genome Project (HGP)

The Human Genome Project (HGP) is an international scientific research project with the primary goal of determining the sequence of chemical base pairs that make up human DNA and identifying and mapping all of the genes in the human genome.

Features of the Human Genome

  • Contains 3.2 billion base pairs.
  • Only 2% of the genome contains genes; the rest is often referred to as “junk DNA.”
  • It is almost identical for all people.

7. DNA Profiling

DNA profiling is a technique used to distinguish between individuals of the same species using samples of their DNA.

8. Genetic Diseases

A genetic disease is a pathological condition caused by an alteration of the genome. A genetic disease can be inherited or not.

Causes of Genetic Diseases

Chromosomal

These diseases affect whole chromosomes or chromosome fragments. An example is Down’s syndrome.

Monogenic

These diseases are due to changes in a single gene and are inherited like any other trait. An example is cystic fibrosis.

9. Prenatal Diagnosis

Prenatal diagnosis is used to diagnose an illness or genetic disease in a developing fetus.

10. Gene Therapy

Gene therapy aims to cure hereditary diseases (caused by defective genes) by introducing healthy genes.

Steps in Gene Therapy

  1. Cells are extracted from the patient.
  2. A virus is modified.
  3. The healthy gene is inserted into the virus.
  4. The virus is introduced to the extracted cells.
  5. The cells’ genetic material is modified by the virus.
  6. The modified cells are injected back into the patient.

11. Implications of Climate Change

  1. Retreat of mountain glaciers during the summer and a decrease in Arctic Ocean ice coverage.
  2. Sea level rise.
  3. Global temperature increase on continents.
  4. Increased frequency of droughts, floods, heat waves, and cyclones.
  5. Changes in the behavior of living organisms.

12. Earth’s Temperature

Earth’s temperature depends on the distance from the sun, which determines the solar radiation received, and the presence and characteristics of the atmosphere.

Atmospheric Composition

Air is composed of 78% nitrogen, 21% oxygen, and 1% argon. CO2 makes up 0.036%. Air also contains water vapor.

Natural Greenhouse Gases

The atmosphere acts as a protective cover, allowing solar radiation to pass through but making it difficult for heat to escape.

Key Greenhouse Gases

  • Water vapor: The main contributor to the natural greenhouse effect.
  • CO2: Emitted by volcanoes and respiring organisms.
  • Methane: Emitted during the digestion of ruminants, in landfills, and in swamps.

13. Greenhouse Effect

  1. Earth receives 100% of solar radiation.
  2. 30% is reflected by the atmosphere and Earth’s surface.
  3. 19% is absorbed by clouds.
  4. 51% is absorbed by Earth’s surface.
  5. The heated surface emits infrared radiation.
  6. Some infrared radiation is absorbed by greenhouse gases and re-emitted back to the surface.
  7. The remaining radiation passes through the atmosphere and escapes into space.

14. Weather vs. Climate

Weather refers to the short-term state of the atmosphere at a specific time and place, determined by factors like temperature, humidity, and precipitation. Climate is the long-term average weather pattern over a period of many years.

15. Sea Level Changes

Sea level changes are influenced by variations in the water cycle (evaporation, precipitation, ice melt) and the thermal expansion of water due to increased temperatures.

16. Climate Change: External Causes

  • Changes in sunspots: Affect the amount of solar energy reaching Earth.
  • Changes in Earth’s orbit: Gradual shifts from a circular to a more elliptical orbit over a 100,000-year cycle.
  • Meteorite impacts: Dust clouds from impacts can affect Earth’s temperature.

17. Climate Change: Internal Causes

  • Changes in albedo: The reflectivity of Earth’s surface, affected by factors like snow cover.
  • Changes in atmospheric composition: Influenced by organisms, volcanic activity, and human activities.

18. Greenhouse Gas-Producing Activities

  • Burning of fossil fuels (gas, oil, and coal).
  • Deforestation.
  • Agricultural and livestock activities (methane emissions from livestock and certain crops).

19. Measures to Address Climate Change

  • Using renewable energy.
  • Improving vehicle emissions.
  • Using more efficient appliances.
  • Protecting and enhancing natural carbon sinks.
  • Recycling.
  • Walking instead of driving.
  • Lowering heating use in winter.