Cell Division: Mitosis and Meiosis Explained
Mitosis
Mitosis, throughout the division of the cell, is characterized by the presence of two fundamental components. Normally, mitotic figures are the chromatic axis and the achromatic axis. The primary chromosome consists of the nucleolus, which can be included as part of the mitotic apparatus. The secondary cycle consists of centrioles, asters, and the spindle.
In-Depth Look
Prophase
Prophase accounts for approximately 40% of the total time of mitosis. It involves both the first series of morphological
Read MoreEarth’s Atmosphere and Environmental Challenges: Composition, Pollution, and Solutions
Earth’s Atmosphere: Composition and Structure
The atmosphere of Earth is composed of about 78% nitrogen, 21% oxygen, 0.04% carbon dioxide, 0.96% argon, and trace amounts of neon, helium, methane, krypton, hydrogen, as well as water vapor.
- Nitrogen: The most plentiful gas in the air, it is one of the primary nutrients critical for the survival of all living organisms.
- Oxygen: Required for the survival of life, green plants produce oxygen during photosynthesis, maintaining a constant oxygen content in
Non-Renewable vs Renewable Energy: Impacts and Sources
Non-Renewable Resources: Advantages and Disadvantages
The energy from renewable sources is relatively inexpensive and easy to obtain. However, fossil fuel reserves are limited. Coal and oil are highly polluting fuels that contribute to acid rain and the greenhouse effect. Nuclear fission reactors produce long-lasting radioactive waste that requires secure storage.
Acid Rain
Sulfur oxides react with water vapor in the upper atmosphere, producing sulfuric acid, while nitrogen oxides produce nitric acid.
Read MoreMaterials Science: Properties, History, and Nanotechnology
Introduction to Materials Science
Everything in the universe exists in a material form. Matter, as it occurs in nature, has specific properties. Matter is constituted by particles. The Big Bang created atoms, initially Hydrogen and Helium. The nucleus of stars produces heavier atoms like Iron. Supernova explosions create the rest of the heavy atoms. Materials can be used as pure substances or mixtures.
Types of Materials
- Raw Materials: Obtained directly from nature, such as wood, granite, and sand.
Soil Formation, Composition, and Conservation
Soils: Formation and Composition
Soils: are formed from the superficial layer of the crust. This process is called pedogenesis.
Stages of Soil Formation:
- Formation of Horizon C: Mainly due to temperature changes, the rocks undergo physical weathering, disintegrating into pieces. Chemical weathering alters some minerals in the rocks.
- Appearance of Horizon A: Living organisms are established on horizon C. First, lichens and mosses, then bacteria, fungi, and finally more evolved living organisms. Living
Rock Deformation, Magmatism, and Seismic Activity
Deformation of Rocks
- Compressive stresses: Convergent forces that usually occur in subduction zones and collision areas.
- Tensional stresses: Divergent forces that act on the rocks of rifts.
- Shear stresses: Transform forces that occur at transform boundaries.
How Do Rocks Respond to Stress?
Rocks respond in an elastic way (they accumulate elastic energy). If the stress continues near the surface, the rocks break and release the elastic energy (they are rigid), causing earthquakes and fault joints.
Factors
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