About 350,000 plant species are currently known. Of this total, over 250,000 are angiosperms. The word angiosperm comes from the Greek angeios, meaning 'purse', and sperma, 'seed'. These plants represent the most varied group of species among the components of the kingdom Plantae or Metaphyta.
Pampa Gaucho is quite different from other Brazilian biomes. Dominated by grass with few trees, it has always been considered more appropriate for cattle breeding. However, in 2004 it was recognized by the Ministry of Environment as a biome. In fact, its biodiversity had been ignored for almost three hundred years.
In ancient times, before the emergence of man, the burning in savanna environments was caused primarily by lightning. With the dominance of the use of fire and the great growth of their populations, man began to increase the frequency of burnings in these environments, as well as changing the time of occurrence of natural burns.
Sulfur is a yellow substance found in soil that burns easily. It enters the production of sulfuric acid, a substance widely used for fertilizers, dyes and explosives (gunpowder, matchsticks, etc.). Sulfur is found in sedimentary rocks (formed by deposits that have accumulated by the action of nature) in volcanic rocks, coal, natural gas etc.
The intensity at which a cell performs photosynthesis can be assessed by the amount of oxygen it releases to the environment, or the amount of CO 2 it consumes. When measuring the photosynthesis rate of a plant, it is clear that this rate may increase or decrease, depending on certain parameters.
Chemosynthesis is a reaction that produces chemical energy, converted from the binding energy of oxidized inorganic compounds. Chemical energy is released, used in the production of organic compounds and oxygen gas (O 2), from the reaction between carbon dioxide (CO 2) and molecular water (H 2 O), as shown below: - First step: Inorganic Compound + O 2 → Oxidized Inorganic Compounds + Chemical Energy - Second Stage: CO 2 + H 2 O + Chemical Energy → Organic Compounds + O 2 This autotrophic process of synthesis of organic compounds occurs in the absence of solar energy.
Fermentative processes lead to the formation of small organic molecules, but still capable of releasing energy. For example, ethyl alcohol, one of the products of glucose fermentation, contains reasonable amounts of releasable energy, both used as fuel. Aerobic respiration consists in carrying out the process of degradation of organic molecules, reducing them to virtually no release energy.
In this phase, the energy contained in ATP and NADPH 2 hydrogens will be used for the construction of glucose molecules. Glucose synthesis occurs during a complex cycle of reactions (called the pentose cycle or the Calvin-Benson cycle), in which several simple compounds participate. During the cycle, CO 2 molecules join together to form carbon chains that lead to glucose production.
Each DNA fragment, which has been cleaved and separated from the rest of the genetic material, contains one or more genes. Remember that each gene originates a protein, so as we study the gene we are studying the protein that it encodes. But what should we do to study the gene? We must introduce it into the genetic material (DNA) of a host for mRNA gene transcription and protein translation to occur.
What it is, what it is: Is it inside your head, is it wrinkled and divided like a giant nut, and it helps you think and do everything? It's him: the brain! The main organ of the nervous system that controls the entire body! He is responsible for all voluntary and involuntary actions of our body. Voluntary actions are those we do willingly: talking, playing, wiggling a toe and many other things.
If instead of inserting in an uterus the egg whose nucleus has been replaced by one of a somatic cell, we allow it to divide in the laboratory, we will be able to use these cells - which in the blastocyst phase are pluripotent - to make different tissues. . This will open fantastic prospects for future treatments because today only cells with the same characteristics of the tissue from which they were taken can be grown in the laboratory.
While simple and easy diffusion and active transport are entry or exit mechanisms for small molecules and ions, large molecules or even particles made up of molecular aggregates are transported through other processes. Endocytosis This process allows the transport of substances from the extracellular medium through membrane-bound vesicles, which are called endocytosis or endocytic vesicles.
As stated above, if two solutions remain separated by a semipermeable membrane, water flows from the most dilute to the most concentrated solution. This diffusion of the solvent is called osmosis. When a plant cell is in a hypotonic environment, it absorbs water. Unlike the animal cell, it does not rupture because it is lined with the cell wall or cellulosic membrane, which is fully permeable but has limited elasticity, restricting the increase in cell volume.
In this process, the substances are transported with energy expenditure and may occur from the lowest to the highest concentration (against the concentration gradient). This gradient can be chemical or electrical, as in ion transport. Active transport acts as a “revolving door”.
Phagocytosis This process is very similar to pinocytosis, the only difference being that the material surrounding the membrane is not diluted. While pinocytosis is a process common to almost all eukaryotic cells, many cells belonging to multicellular organisms do not perform phagocytosis, but are made by specific cells.
Early cytologists believed that the inside of the living cell was filled with a smooth, viscous fluid into which the nucleus was immersed. This fluid is called cytoplasm (from the Greek kytos, cell, and plasma, that which forms, which shapes). It is now known that the space between the plasma membrane and the nucleus is quite different than those pioneer cytologists imagined.
In plant cells that are exposed to light, such as leaf cells, for example, proplasts grow into chloroplasts. The need for light for their formation explains why there are no chloroplasts in the cells of unenlightened parts of plants, such as the roots or the inner parts of the stems.
Plasma membrane proteins perform a variety of functions: they act preferentially on transport mechanisms, organizing true tunnels that allow substances to pass into and out of the cell, function as membrane receptors, and receive signals from substances that carry some message to the cell, favor adhesion of adjacent cells in a tissue, serve as anchor point for the cytoskeleton.
Translation is a process in which the message contained in the mRNA molecule will be read by ribosomes, decoding the nucleic acid language to the protein language. Each tRNA in solution binds to a particular amino acid, forming a molecule called aminoacyl-tRNA, which will contain, at the anticodon end, a trio of mRNA codon.
Scottish researcher Robert Brown (1773-1858) is considered the discoverer of the cell nucleus. Although many previous cytologists had already observed nuclei, they had not understood the enormous importance of these structures for cell life. Brown's great merit was precisely to recognize the nucleus as a fundamental component of cells.