Notes, abstracts, papers, exams and problems of Biology

1. Bioelements O biogenic elements.

Are the chemical elements that are part of living matter. We found about 70 chemical elements forming part of living matter, these are in various proportions and not all are present in all living things. In accordance with its wealth divide:
Bioelements-primary.
Bioelements-side.

• Bioelements Primary: These are found in greater proportion, are present in all biomolecules. Represents around 95% by weight of living matter. They are the C, O, H, N and to a lesser extent P and S.
  These items have been selected among all those who constitute the Earth's crust to form living matter, although except oxygen are the most abundant, possessing features among which are the following:

1-have incomplete outer electron... Continue reading "Bioelements" »

GMO - Genetically modified organisms


Benefits and Risks
Advantages
Key benefits of biotechnology are:
·
Superior performance. By GMO crop yield increases, giving more food for fewer resources, reducing crop losses as well as environmental factors

• Reduced pesticide Whenever a GMO is modified to resist a particular pest is helping to reduce pesticide use associated with it that often cause widespread environmental damage and health. ^[

• Improved nutrition can be reached by introducing vitamins and protein on food and reduce the allergens and natural toxins. You can also try to grow in extreme conditions as auxiliaries to the countries that have less food available.

Improves the development of new materiales.La application of biotechnology... Continue reading "Advantages and disadvantages of biotechnology" »

POSITIONS OF PLACEMENT OF PATIENTS
Supine or dorsal
In the anatomical position, the patient remains with his hands on either side of the body, arms extended, adducted thumbs and hands of pronation.
The head is held erect and the feet pointing forward. The knees and fingers in slight flexion
The patient is lying on your back with legs extended, attached to the upper and lower body together.
Uses:
· Examination of the chest, abdomen, upper and lower limbs.
· Postoperative.
And Accommodation in bed
· Position change.
· Palpation of the breasts.
Contraindications:
· Elders.
· Lung disease.
Sick of long-term ·
Prone position or ventral


Also called prone. In this position the patient lies on his abdomen and chest, his head... Continue reading "Positions" »

Corn
Kingdom Plantae
Traqueofita Division
Angiosperm Class
Subclass Monocotyledoneae
Cereals Order
Family Poaceae (Gramineae)
Scientific name (genus and species) Zea mays

Bean

Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Subclass:	Rosidae
Order:	Fabales
Family:	Fabaceae
Subfamily:	Faboideae
Tribe:	Phaseoleae
Subtribe:

... Continue reading "Example of classification of animals: kingdom, family, class, order and scientific names" »

Unit 1: Nerve Fibers

A nerve fiber is a long, slender projection of a neuron (nerve cell) that carries electrical signals throughout the nervous system. It transmits information between the brain, spinal cord, and other parts of the body.

Nerve Fiber Classification

By Diameter and Conduction Velocity:

• Type A (Myelinated, fast conduction):
  • Aα: Large diameter; motor functions and proprioception.
  • Aβ: Touch and pressure.
  • Aγ: Muscle spindle function.
  • Aδ: Pain and temperature.
• Type B (Myelinated, medium diameter): Autonomic functions.
• Type C (Unmyelinated, slow conduction): Pain, temperature, and some autonomic functions.

By Function:

• Sensory Fibers: Transmit sensory information (e.g., touch, pain).
• Motor Fibers: Control muscle movements.
• Autonomic Fibers:

... Continue reading "Nerve Fibers and the Human Brain: Structure and Function" »

Active Transport

Active transport moves substances across membranes from lower to higher concentration, against the concentration gradient. This process requires cellular energy (ATP) and a carrier protein.

The substance binds to the carrier protein's receptor site on one side of the membrane. ATP changes the protein's shape, releasing the substance on the other side. Active transport occurs only in living, respiring cells.

Factors influencing active transport:

• ATP Production: Increased ATP production increases active transport rate.
• Temperature and Oxygen: These affect respiration and ATP production, thus impacting transport rate.
• Mitochondria: Cells with more mitochondria have higher transport rates due to increased ATP production.
• Poisons: Respiratory

... Continue reading "Active & Passive Transport in Plants: A Comprehensive Guide" »

Local Inflammation

1. Occurs when bacteria enter a break in the skin.
2. Inflammatory reaction is initiated by nonspecific mechanisms of phagocytosis and complement activation.
3. Complement activation attracts phagocytes to the area.
4. As inflammation progresses, B cells produce antibodies against bacterial antigens.
5. Attachment of antibodies to antigens amplifies nonspecific responses because of complement activation.
6. Promotes phagocytic activity of neutrophils, macrophages, and monocytes (through opsonization).
7. In the inflamed area, leukocytes attach to the surface of endothelial cells.
8. Move by chemotaxis to the inflamed site.

• Neutrophils arrive first, then monocytes, then T cells.
  • Undergo extravasation (the entire process of movement of leukocytes from the bloodstream

... Continue reading "Understanding Local Inflammation and Fever Response" »

Infrared Spectra of Alkanes

Alkanes, being saturated hydrocarbons, only contain Carbon-Carbon (C-C) and carbon-hydrogen single bonds. Their IR spectra are relatively simple due to the absence of strong functional groups.

C-H Stretching

The most prominent peaks in an alkane's IR spectrum are due to C-H stretching vibrations. These sharp, strong bands typically appear in the range of 2850-2960 cm^-1. The exact wavenumber can vary slightly depending on the specific alkane and its branching.

Infrared Spectra of Alkenes

Alkenes contain at least one carbon-carbon double bond (C=C), along with C-H bonds. The presence of the double bond introduces distinct features in their IR spectra compared to alkanes.

C=C Stretching

The stretching vibration of the C=C... Continue reading "Infrared Spectroscopy of Organic Compounds: A Comprehensive Guide" »

Plasmids pBR322 and pUC18/19

pBR322

pBR322, developed in 1977, is a foundational plasmid in molecular biology. Key features include:

• Size: ~4,361 base pairs (bp)
• Origin of Replication: Allows independent replication within bacteria.
• Selection Markers:
  • ampR: Confers ampicillin resistance.
  • tetR: Confers tetracycline resistance.
• Cloning Sites: Multiple sites for inserting foreign DNA.
• Applications: Gene cloning, expression, and manipulation.

pUC18/19

pUC18/19, derived from pBR322 in the early 1980s, simplifies cloning. Key features include:

• Size: ~2,686 bp
• Origin of Replication: High-copy-number pMB1 ori for increased yield.
• Selection Marker:
  • lacZ: Beta-galactosidase gene; enables blue/white screening for insert identification.
• Cloning Sites: Multiple cloning

... Continue reading "Plasmids pBR322 and pUC18/19: Cloning Vectors" »

Mineral Trioxide Aggregate (MTA) Applications

Pulp Therapy

• Pulp capping
• Furcation repair
• Strip perforation repair
• Root resorption repair
• Immature teeth
• Root end filling material

Elements of Pulp Regeneration

Therapy for exposed dental pulps using stem cells and a biofunctional scaffold, inhibiting or eliminating infection to facilitate pulp generation.

Nickel-Titanium (NiTi) Rotary Instruments

Advantages of NiTi Reciprocation

• Mimics manual movement
• Reduces risks associated with continuous rotation in curved canals

Types of Posts

1. Carbon fiber epoxy resin posts
2. Zirconia posts
3. Glass fiber reinforced posts
4. Ultra-high strength polyethylene fiber reinforced posts

Advantages of NiTi Rotary

• Gradual, evenly tapered radicular preparation
• Fewer instruments required
• Reduced

... Continue reading "Mineral Trioxide Aggregate (MTA) Applications & Luxation Injuries" »