Macronutrients and Micronutrients: Essential Roles in Human Health
Macronutrients
In nutrition, macronutrients are those nutrients that supply most of the body’s metabolic energy. The main ones are carbohydrates, proteins, and fats. Others include alcohol and organic acids. They differ from micronutrients like vitamins and minerals, as these are needed in small amounts to maintain health but not for energy.
Life is sustained by food, and substances in foods on which life depends are the nutrients. These provide energy and building materials for many substances that
Read MoreCell Division: Cytokinesis, Meiosis, and Reproduction Types
Cytokinesis: Division of the Cytoplasm
Cytokinesis is the division of the cytoplasm. In animal cells, it occurs by constriction, and in plant cells, by intracellular septation.
Animal Cells
In animal cells, cytokinesis starts at the end of anaphase with the invagination of the plasma membrane in the equatorial zone, forming the cleavage furrow. Inside the cell, a contractile ring of actin and myosin forms, constricting the cell until it divides the cytoplasm, resulting in two daughter cells.
Plant Cells
In
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The Discovery of the Cell: The Cell Theory
Robert Hooke discovered the cell when looking through a microscope, made by himself, at a very thin sheet of cork. In the nineteenth century, the improvement of microscopes and the discovery of techniques to stain preparations allowed for the observation of new cellular structures.
- The botanist Robert Brown, in 1831, found a particle inside plant cells which he called the nucleus.
- Johannes Purkinje, in 1838, introduced the term protoplasm to describe the liquid
Workplace Safety: Personal Protective Equipment and Emergency Response
Personal Protective Equipment (PPE)
PPE is divided into two classes:
- PPE Respiratory
- Non-Respiratory PPE: These protect the head, eyes, feet, hands, and body.
Head Protection
The head is protected with a previously regulated helmet designed to withstand high shock loads. It should absorb the potential energy from falling objects and distribute the blow. The helmet must be dielectric, meaning it does not conduct electricity. It has the following parts:
- Adjustable basket
- Visor for protection from direct
Ecosystems: Biocenosis, Biotope, and Ecological Factors
Ecosystems: Biocenosis, Biotope, and Their Interactions
Key Components of an Ecosystem
- Ecosystem: The combination of the biocenosis, the biotope, and the relationships established between them, as well as the relationship between the biotope and biocenosis.
- Community or Biocenosis: The whole population that shares a territory and establishes relations between them. It is composed of all living things.
- Biotope: The territory occupied by a biocenosis, presenting specific physical and climatic characteristics.
Circulatory and Excretory Systems in Animals: Function and Diversity
Nursery: Transport
Liquids possess multicellular intracellular (inside the cells) and extracellular (liquids bathing cells) components. This internal environment is formed by interstitial liquid and blood, and it renews lymph. It leads to nutrients and withdraws waste.
Sponges
They have no internal environment; the aquatic environment in which they live is in charge of nourishing them. This is favored by flagellar, ciliary, or corporal movements, which allow water to flow through the animal’s body.
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