It is proved that the cells of eukaryotic organisms are represented by a system of membranes that form organelles of protein-phospholipid composition. However, there is an important exception to this rule. Two organelles (cell center and ribosome), as well as movement organelles (flagella and cilia) have a non-membrane structure. How are they educated?
Science 2024, November
Chemistry is the foundation of our life. All household items consist of compounds of the elements of the periodic table. Every minute in the human body there are complex transformations in which chemicals are involved. This article will talk about the metal molybdenum: where it is used, its properties and role in the human body
Sleep experts recommend using white noise. It can be the sounds of nature, the buzzing of a vacuum cleaner and others. They are no less effective than mother's lullaby
A lighter-than-air aircraft uses Archimedean - buoyant - force to lift. It is also called an aerostat. This device is equipped with a shell filled with hot air or a gas having a lower density than the surrounding atmosphere
If the linear movement of bodies is described in classical mechanics using Newton's laws, then the characteristics of the movement of mechanical systems along circular trajectories are calculated using a special expression, which is called the equation of moments. What moments are we talking about and what is the meaning of this equation? These and other questions are discussed in the article
Modern people are the descendants of a small population of about 1-2 thousand people. Gradually, settlement occurred throughout the globe, and people were divided into races and adaptive traits, as a result of the impact of various environmental factors. From the article you will learn the characteristics of adaptive types of a person
Let's try to figure out what the process of socialization is, what functions it performs and what stages it consists of
In social science, a person is a person who has certain social properties. Based on the definition, it can be understood that this concept is inextricably linked with society. Let's take a look at it in more detail
Encyclopedia is a unique publication that will help both schoolchildren to prepare for writing a report or message, and parents to learn a lot of new interesting facts. The most convenient thing is that now to get acquainted with encyclopedias it is not at all necessary to purchase these beautiful, but expensive books or visit libraries
Learn how to determine who the child will look like. What determines gender, eye color and other characteristics
Metals are the most important and in many ways unique chemical elements. Almost all of them are characterized by such properties as good electrical conductivity, gloss, thermal conductivity. At the same time, separate groups can be distinguished among them, the characteristics of which will differ significantly. Some of these distinctive features formed the basis of such a concept as the "activity series of metals"
Specific electrical conductivity characterizes the general ability of a body to be a conductor of electric current
Statistical methods of data analysis are described in sufficient detail in the domestic literature. In the practice of Russian enterprises, meanwhile, only some of them are used
What is the edaphic factor? How does it affect the life of plants and animals? Read the answers to these questions in the article
The article is devoted to steppe soils. The main characteristic features of such covers, features of chernozems and dry soils are considered
People study the culture and life of ancient civilizations, restoring the distant past from the remains, which are carefully dug up in the layers of the earth. This work requires great care and diligence, as over time the remains of the past become more fragile and dilapidated
Water is the basis of life. Without this substance, the existence of not a single living being on our planet is possible. How to analyze tap water? How to define quality? Together we will look for answers to the questions posed
Uzbekistan is a state in Central Asia, one of the former republics of the USSR. Moreover, this is the happiest post-Soviet country (according to the World Happiness Report). The article describes in detail the population of Uzbekistan, its size and ethnic composition
The gravitational drive has long been considered by scientists as a kind of pipe dream that looks beautiful in theory, but is not feasible in practical terms. However, in recent years, in connection with the development of certain areas of physical science, this type of perpetuum mobile began to gradually acquire quite real outlines
Today we will consider the basic concept of probability theory, learn how to solve problems using specific examples
The most important organ, without which it is impossible to imagine the digestive processes of life. Human pharynx: what are its functions and structure?
Pierce Charles Sanders is an American philosopher, logician, mathematician and scientist, whom some call the "father of pragmatism". He was educated as a chemist and worked as a scientist for 30 years. He will be appreciated for his huge contribution to logic, mathematics, philosophy and semiotics. Also, the American scientist is popular for putting forward the main provisions of the philosophical current of pragmatism
What is the Monty Hall paradox? This is a clear illustration of the inability of a person to weigh his chances of success in terms of choosing a favorable outcome in the presence of more than one unfavorable
Earlier, young people who wanted to gnaw at the granite of science could enter vocational schools, technical schools and universities. The first two types of educational institutions issued diplomas of specialized secondary education, and the last - of completed higher education. However, now the situation has changed somewhat. Applicant for a post - bachelor comes. “Is this higher education or not?” the employer thinks. The question, at least in Russia, is somewhat confusing. Let's try to figure it out
Social constructivism is a theory of cognition and learning that argues that the categories of knowledge and reality are actively created by social relationships and interactions. According to social constructivist learning theory, each of us is formed through our own experiences and interactions
All representatives of the Chordata type are conditionally divided into higher and lower. The first includes the Vertebrate subtype, which is characterized by the presence of a skeleton of bones and cartilage. A typical taxon is a representative of the lower chordates, subphylum Cranial. A distinctive feature of this group is the presence of a chord at all stages of the life cycle
Many people like to do tricks and experiments. Firstly, it is interesting, and secondly, it is an easy way to entertain children. Experiments with an egg help the child learn about the simplest chemical reactions and the laws of physics
Characteristics of the constellation Peacock: designation, official borders, neighboring constellations. The history of the accumulation. Ancient Greek myth about the origin of the constellation. Objects of note: stars, exoplanets, deep sky objects
Ever since the primary school years, we all clearly learned the rule "you cannot divide by zero." But if in childhood you take a lot on faith and the words of an adult rarely raise doubts, then over time, sometimes you still want to understand the reasons, to understand why certain rules were established
Ontogeny of any organism is characterized by the formation of germ layers. In such primitive types of animals as coelenterates and sponges, the embryo consists of only two layers: endoderm and ectoderm. Over time, in more progressive forms of organisms, a third leaf appears - the mesoderm
The process is a crystal growth method used to produce single crystals of semiconductors (such as silicon, germanium and gallium arsenide), metals (such as palladium, platinum, silver, gold), s alts and synthetic gemstones
Discourse on the method of just reasoning and the search for truth in the sciences (French: Discours de la Méthode Pour bien conduire sa raison, et chercher la vérité dans les Sciences) is a philosophical and autobiographical treatise published by René Descartes in 1637
Moving in any conductor, an electric current transfers some energy to it, which causes the conductor to heat up. Energy transfer is carried out at the level of molecules: as a result of the interaction of current electrons with ions or atoms of the conductor, part of the energy remains with the latter. The thermal effect of the current leads to a faster movement of the conductor particles. Then its internal energy increases and transforms into heat
There are a huge variety of versions of the origin of man on Earth. Among them there are theories supported by archaeological finds and scientific research, and there are much more utopian ones. In any case, none of the versions has so far been able to absolutely convincingly prove
Carbon is one of the most important elements of the planet. Characterization of carbon and its compounds, allotropic modifications. Element Discovery History
What to do if the frenulum of the penis in men is short? What is fraught with a short bridle in men? What are the signs that a man has a short frenulum on his penis?
Secondary metabolites: description of substances, their role in plant biochemistry. Features and main characteristics of these compounds. Existing classifications. The influence of secondary metabolites on the human body and their use in pharmaceuticals
The phrase "artificial intelligence systems" for many evokes associations with various science fiction films and interlocutor programs that emulate artificial intelligence. Robots have become a reality in our time, and every time you open another exhibition dedicated to robotics, you are surprised how far mankind has advanced in its technological progress
Histology is the study through microscopic enlargement of fragments of tissues and cells to determine the structure and shape of organ cells. The endocrine system is a complex and not fully understood area of biology and medicine. Its study is just beginning and has many mysteries
A biological system implies a hierarchical structure and subordination of systems and structural components in its development