Relict tree The oldest tree on the planet is considered ginkgo biloba. During the Mesozoic, it was widespread on Earth, especially in northern latitudes, in temperate climate areas with high humidity. Many of them were also on the lands of the present Siberia. After the ice age, only one species of ginkgo out of fifty … Read more
Each body relative to the electric current is characterized by its resistance. If we recall electronic theory, according to it, all substances consist of atoms and molecules. These atoms and molecules in different substances have different structure. And they are the ones that occur in the way of motion of free electrons in the conductor … Read more
Cell wall structure Fungi cells , like plant cells, are surrounded on the outside by a strong cell wall that supports the shape of the cell and protects it from damage. In most fungi, the cell wall consists of chitin, a substance that also forms an exoskeleton in insects, and only in oomycetes the main … Read more
Instruction 1 Noise adversely affects a person, and its negative impact depends on the volume and duration. Strong and sharp sound will do much more harm than constant non-loud hum. Auditory stimuli are able to influence the emotional state of a person and the motivation of their actions. Noise can become a cause of intra-family … Read more
A device with which to measure the force of current flowing through the circuit is called an ammeter. Since the values that the instrument produces (current) depend on the resistance of the elements inside the ammeter, it must be very low. The internal device of the ammeter depends on the purpose of use, type of … Read more
How to absorb water roots and mineral salts from the soil Starting from the tip, the root consists of four areas: division zone, stretch zone (zones) growth), the suction zone and the holding area. The suction zone at the root is about 2-3 cm long. From the cells of the outer cover of the root … Read more
The structure of the plasma membrane Cytoplasmic membrane has a thickness of 8-12 nm, so it is impossible to consider it in a light microscope. The structure of the membrane is studied using an electron microscope. The plasmic membrane is formed by two layers of lipids — the bilipid layer, or bilayer. Each lipid molecule … Read more
General Pacific Ocean is the largest ocean on Earth. It occupies about 33% of its surface and contains more than 50% of all seawater. It got its name after the voyage of F. Magellana by its waters in 1520. For that period, the ocean was calm, so a Portuguese navigator described it as “pacific” (quiet). … Read more
Instruction 1 of the Conception of Psychology can be found back in ancient Greece. Many philosophers have pondered why one person behaves this way and another person behaves differently, why people react in a certain way to any events. Theories were built very different. Plato expressed the opinion that the soul of man before birth … Read more
Instruction 1 Since ancient times people have paid attention to the favorable effects of forest, mountain and sea air. This can be explained by the fact that in these localities oxygen particles are ionized negatively, which benefits the body. That is why in case of frequent headaches, maladies specialists recommend outdoor walks. In the forest … Read more