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" »

The Human Circulatory and Respiratory Systems

Key Components and Functions

1. The Diaphragm's Role in Respiration

The diaphragm separates the thoracic cavity (containing the heart, lungs, and ribs) from the abdominal cavity. It plays a crucial role in respiration. As the diaphragm contracts, the volume of the thoracic cavity increases, drawing air into the lungs.

2. Arteries: Transporting Oxygenated Blood

Arteries are large, thick-walled, muscular blood vessels that carry oxygenated blood away from the heart.

• Pulmonary Arteries: Carry deoxygenated blood from the heart to the lungs.
• Umbilical Arteries: Paired arteries (one for each half of the body) found in the abdominal and pelvic regions. They supply deoxygenated blood from the fetus to the placenta

... Continue reading "Human Circulatory and Respiratory Systems: Key Functions" »

Lymphocyte Migration and Immune Response

Lymphocytes constantly migrate through the blood and lymph, moving from one lymphoid organ to another. This process:

• Enhances the chance that an antibody will encounter its specific antigen.
• The spleen filters blood, while other lymphoid organs filter lymph.

Phagocytosis: A Non-Specific Innate Immune Response

Phagocytosis is the ingestion of microorganisms or particulate matter by a cell. It is performed by phagocytes, which are certain types of white blood cells or their derivatives.

Actions of Phagocytic Cells

1. Among the granulocytes, neutrophils are the most important phagocytes.
2. Enlarged monocytes transform into wandering macrophages and fixed macrophages.
3. Fixed macrophages are located in selected tissues

... Continue reading "Understanding Phagocytosis and Immune Responses" »

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" »

Most living things obtain their energy either directly or indirectly from the energy of sunlight captured through photosynthesis.

Photosynthesis in 2 Stages

1. Pigments in the leaves' cells (chlorophyll) capture or absorb the sun's energy, which is used to power the second stage. The leaf cells also need water (absorbed through roots) and carbon dioxide (that enters through small openings on the undersides of leaves called stomata).
2. Inside the chloroplasts, water and carbon dioxide are transformed into glucose and oxygen. Plants use glucose for food and store what they don't need as starch (energy for later use) and cellulose (that makes up the cell walls). Oxygen and water exit the leaf through the stomata.

Stomata

Carbon dioxide enters the plant... Continue reading "Photosynthesis and Cellular Respiration in Plants" »