Cellular Organization: Abiotic and Biotic Levels Explained
1. Levels of Organization: The Atom in the Body
All matter in the universe is made up of atoms. Living beings are also composed of atoms, although we are a complex mix of chemicals, highly organized into complex structures. The successive structural complexity that organizes matter, from the atom to the creature, is known as organizational levels.
1.1 Levels of Organization
1.1.1 Abiotic Levels
Abiotic levels comprise different levels of organization of matter without life.
- Atomic Level: This is the
MRI and fMRI: History, Components, and Signal Measurement
A Brief History of MRI & fMRI
- 1921/22 – Quantum Spin Discovered (Stern & Gerlach): Showed that atomic particles have intrinsic quantum properties (spin), a foundation for magnetic resonance.
- 1946 – Nuclear Magnetic Resonance (NMR) in Bulk Matter (Bloch & Purcell): Demonstrated that nuclei in a magnetic field absorb and re-emit radio waves, leading to MRI development.
- 1971 – First Medical Application of MRI (Damadian): Showed cancerous tissue has different NMR signals than healthy
Understanding the Biosphere: Components, Habitats, and Ecological Niches
The Biosphere: An Introduction
The biosphere is the combination of living organisms and the physical environment in which life developed, namely: land, air, and water.
Some authors define it as a thin spider’s web, about 15 km thick, which is taken at the changing shapes of the planet’s surface.
Key Components of an Ecosystem
Biotopes
A biotope is the set of physical factors that exist in an ecosystem: air, water, light, temperature, etc.
Biocenosis
Biocenosis is the set of creatures that inhabit the ecosystem:
Read MoreMicrobial Applications and Immune Response Mechanisms
Microbial Applications
Microbes are mixed, culture medium is added, valves release gas, and a tap extracts the fermentation product. Examples include:
- Alcohol Fermentation: Wine, ethanol production.
- Lactic Acid Fermentation: Production of substances for anemia treatment and plasticizers.
- Vinegar Production: Certain bacteria degrade acetic acid.
Industrial Applications of Microbes
- Antibiotic Production: Substances produced that affect other living organisms. For example, penicillin inhibits bacterial wall
Nervous System: Structure, Function, and Signal Transmission
The Nervous System: Structure and Function
The nervous system, composed of nervous tissue, is responsible for regulating bodily functions through nerve impulses. In contrast, the endocrine system, consisting of endocrine glands, coordinates and regulates certain physiological functions through hormones transported by the blood. The nervous system’s response is rapid, short-lived, and very specific, whereas the hormonal response is slow, lasting, and of variable specificity.
The functions that require
Read MoreProkaryotic and Eukaryotic Cells: Key Differences
Key Differences Between Prokaryotic and Eukaryotic Cells
June 07
B1OB
1. a. Prokaryotes:
- DNA is located in a Nucleoid region, not surrounded by a membrane.
- Direct cell division, mainly by binary fission.
- No centrioles and spindle microtubules.
- Sexual systems are few; if any sexual intercourse occurs, it is by transfer from a donor to a recipient.
- Few multicellular forms; absence of tissue development.
- Anaerobic, facultative, aerobic, and microaerophilic forms.
- Absence of mitochondria: enzymes for oxidation