The process of transferring genetic information. Stages of protein synthesis. Methods of transmitting information in a cell General definition of coding and code. Coding tasks

There are three main ways of transmitting information; each is used in the cage for a different purpose (see pictures below).

The transmission of genetic information consists of duplication (left), transcription (right) and translation (see pictures below). Genetic information is recorded in giant chains of deoxyribonucleic acid (DNA) molecules. The coding “letters” are four bases: adenine (A), thymine (T), guanine (G) and cytosine (C). Ordinary DNA consists of two complementary strands, in which A pairs with T, and G pairs with C. During duplication, a new complementary DNA strand is synthesized on each of the parent strands using an unknown mechanism. During transcription, only one strand of DNA serves as a template, on which a ribonucleic acid (RNA) molecule is formed. In the RNA molecule, instead of adenine, it is not thymine, but uracil (U). RNA molecules are divided into “translatable” (information) and “untranslatable”.

The process of translation involves translating genetic information from the four-letter “language” of nucleic acids (DNA and RNA) into the twenty-letter “language” of proteins. The “letters” of the protein “language” are 20 amino acids that are connected into protein chains. The DNA code is “rewritten” into the structure of messenger RNA, which binds to one or more particles, the so-called ribosomes, where protein synthesis occurs. Ribosomes consist of protein and two types of non-messenger RNA (16 S-RNA and 23 S-RNA). There is also soluble, or transport, RNA; its function is to transport amino acids to the site of protein synthesis. Apparently, each amino acid is encoded in messenger RNA by a group of three bases. According to the generally accepted hypothesis, the coding group is “recognized” by a complementary set of bases in the transfer RNA. Ribosomes apparently serve as a kind of clamping device for adding amino acids to the growing protein chain as the “tape” of messenger RNA is pulled through.

The first method is duplication, or doubling, that is, the formation of exact copies of a DNA molecule for transmission to the next generation of cells. During the copying process, the “language” and “alphabet” remain unchanged.

The second method, transcription, or rewriting, uses the same language but a slightly modified alphabet. At this stage, the DNA molecule is “rewritten” into a ribonucleic acid (RNA) molecule; its chains are built, like DNA chains, from four coding units. Three of them (A, G and C) are the same as in DNA, but instead of the fourth - thymine (T) - there is uracil (U). One specific type of RNA carries all the necessary programs for protein synthesis. This RNA is often called “messenger RNA,” but I prefer the terms “translated” or “information” RNA: information can be translated, but “messenger” cannot.

The third method of transmitting information, rightly called translation, or translation, is to translate from the language of messenger RNA (a four-letter alphabet) into the language of proteins (a twenty-letter alphabet). Every translation requires a dictionary; The cage also has its own dictionary. It consists of a set of relatively small molecules called transport (or soluble) RNA; their task is reduced to the transfer of specific amino acids to the site of protein synthesis. The connection of each amino acid with a transfer RNA molecule is catalyzed by a specific activating enzyme.

"Molecules and Cells", ed. G.M. Frank

The process of information transfer is shown schematically in the figure. It is assumed that there is a source and recipient of information. The message from the source to the recipient is transmitted through a communication channel (information channel).

Rice. 3. – Information transfer process

In this process, information is presented and transmitted in the form of a certain sequence of signals, symbols, signs. For example, during a direct conversation between people, sound signals are transmitted - speech; when reading a text, a person perceives letters - graphic symbols. The transmitted sequence is called a message. From the source to the receiver, the message is transmitted through some material medium (sound - acoustic waves in the atmosphere, image - light electromagnetic waves). If technical means of communication are used during the transmission process, they are called information transmission channels(information channels). These include telephone, radio, television.

We can say that human senses act as biological information channels. With their help, the informational impact on a person is conveyed to memory.

Claude Shannon, a diagram of the process of transmitting information through technical communication channels was proposed, shown in the figure.

Rice. 4. – Process of information transfer according to Shannon

The operation of such a scheme can be explained in the process of talking on the phone. The source of information is the person speaking. The encoding device is a telephone handset microphone, with the help of which sound waves (speech) are converted into electrical signals. The communication channel is the telephone network (wires, switches of telephone nodes through which the signal passes)). The decoding device is the handset (earphone) of the listening person - the receiver of information. Here the incoming electrical signal is converted into sound.

Communication in which transmission is in the form of a continuous electrical signal is called analog communication.

Under coding refers to any transformation of information coming from a source into a form suitable for its transmission over a communication channel.

Currently, digital communications are widely used, when the transmitted information is encoded in binary form (0 and 1 are binary digits), and then decoded into text, image, sound. Digital communication is discrete.

The term “noise” refers to various types of interference that distort the transmitted signal and lead to loss of information. Such interference, first of all, arises for technical reasons: poor quality of communication lines, insecurity of different streams of information transmitted over the same channels from each other. In such cases, noise protection is necessary.

First of all, technical methods are used to protect communication channels from noise. For example, using a screen cable instead of a bare wire; the use of various types of filters that separate the useful signal from noise, etc.

Claude Shannon developed a special coding theory that provides methods for dealing with noise. One of the important ideas of this theory is that the code transmitted over the communication line must be redundant. Due to this, the loss of some part of the information during transmission can be compensated.

However, the redundancy should not be too large. This will lead to delays and increased communication costs. K. Shannon's coding theory allows us to obtain a code that will be optimal. In this case, the redundancy of the transmitted information will be the minimum possible, and the reliability of the received information will be maximum.

In modern digital communication systems, the following technique is often used to combat the loss of information during transmission. The entire message is divided into portions - blocks. For each block, a checksum (the sum of binary digits) is calculated and transmitted along with the block. At the receiving site, the checksum of the received block is recalculated, and if it does not coincide with the original one, then the transmission of this block is repeated. This will happen until the source and destination checksums match.

Information transfer rate is the information volume of a message transmitted per unit of time. Units of information flow speed: bit/s, byte/s, etc.

Technical information communication lines (telephone lines, radio communications, fiber optic cable) have a data transfer speed limit called information channel capacity. Transmission speed restrictions are physical in nature.

(Answers at the end of the test)

A1. Which science classifies organisms based on their relatedness?

1) ecology

2) taxonomy

3) morphology

4) paleontology

A2. What theory was formulated by the German scientists M. Schleiden and T. Schwann?

1) evolution

2) chromosomal

3) cellular

4) ontogeny

A3. The storage carbohydrate in an animal cell is

1) starch

2) glycogen

4) cellulose

A4. How many chromosomes are in the germ cells of the fruit fly Drosophila if its somatic cells contain 8 chromosomes?

A5. The integration of its nucleic acid into the DNA of the host cell is carried out

1) bacteriophages

2) chemotrophs

3) autotrophs

4) cyanobacteria

A6. Sexual reproduction of organisms is evolutionarily more progressive, since it

1) contributes to their wide distribution in nature

2) ensures a rapid increase in numbers

3) contributes to the emergence of a wide variety of genotypes

4) preserves the genetic stability of the species

A7. What are individuals called that form one type of gametes and do not produce splitting of characters into offspring?

1) mutant

2) heterotic

3) heterozygous

4) homozygous

A8. How are the genotypes of individuals designated during dihybrid crossing?

A9. All leaves of one plant have the same genotype, but may differ in

1) number of chromosomes

2) phenotype

3) gene pool

4) genetic code

A10. What bacteria improve nitrogen nutrition of plants?

1) fermentation

2) nodule

3) acetic acid

A11. An underground shoot differs from a root in that it has

2) growth zones

3) vessels

A12. Plants of the angiosperm division, unlike gymnosperms,

1) have a root, stem, leaves

2) have a flower and a fruit

3) reproduce by seeds

4) release oxygen into the atmosphere during photosynthesis

A13. In birds, unlike reptiles,

1) unstable body temperature

2) cover of horny substance

3) constant body temperature

4) reproduction by eggs

A14. Which group of tissues has the properties of excitability and contractility?

1) muscular

2) epithelial

3) nervous

4) connecting

A15. The main function of the kidneys in mammals and humans is to remove them from the body.

2) excess sugar

3) metabolic products

4) undigested residues

A16. Human phagocytes are capable

1) capture foreign bodies

2) produce hemoglobin

3) participate in blood clotting

4) transfer antigens

A17. Bundles of long processes of neurons, covered with a connective tissue membrane and located outside the central nervous system, form

2) cerebellum

3) spinal cord

4) cerebral cortex

A18. What vitamin should be included in a person's diet to prevent scurvy?

A19. What species criterion should be used to classify the area of ​​distribution of reindeer in the tundra?

1) environmental

2) genetic

3) morphological

4) geographical

A20. An example of interspecies struggle for existence is the relationship between

1) an adult frog and a tadpole

2) a cabbage butterfly and its caterpillar

3) song thrush and fieldfare thrush

4) wolves of the same pack

A21. The tiered arrangement of plants in the forest serves as an adaptation to

1) cross pollination

2) wind protection

3) use of light energy

4) reducing water evaporation

A22. Which factor in human evolution is social in nature?

1) articulate speech

2) variability

3) natural selection

4) heredity

A23. What is the nature of the relationships between organisms of different species that need the same food resources?

1) predator - prey

3) competition

4) mutual assistance

A24. In the biogeocenosis of a water meadow, decomposers include

1) cereals, sedges

2) bacteria and fungi

3) mouse-like rodents

4) herbivorous insects

A25. Can lead to global changes in the biosphere

1) increase in the number of individual species

2) desertification of territories

3) heavy rainfall

4) replacement of one community by another

A26. What percentage of nucleotides containing cytosine does DNA contain if the proportion of its adenine nucleotides is 10% of the total?

A27. Select the correct sequence of information transfer during the process of protein synthesis in the cell.

1) DNA → messenger RNA → protein

2) DNA → transfer RNA → protein

3) ribosomal RNA → transfer RNA → protein

4) ribosomal RNA → DNA → transfer RNA → protein

A28. With dihybrid crossing and independent inheritance of traits in parents with genotypes AABb and aabb, a split in the ratio is observed in the offspring

A29. In plant breeding, pure lines are obtained by

1) cross pollination

2) self-pollination

3) experimental mutagenesis

4) interspecific hybridization

A30. Reptiles are considered true terrestrial vertebrates because they

1) breathe atmospheric oxygen

2) reproduce on land

3) lay eggs

4) have lungs

A31. Carbohydrates in the human body are stored in

1) liver and muscles

2) subcutaneous tissue

3) pancreas

4) intestinal walls

A32. The secretion of saliva, which occurs when the receptors of the oral cavity are irritated, is a reflex

1) conditional, requiring reinforcement

2) unconditional, inherited

3) arising during the life of humans and animals

4) individual for each person

A33. Among the listed examples, aromorphosis is

1) flat body shape of the stingray

2) protective coloration in a grasshopper

3) four-chambered heart in birds

A34. The biosphere is an open ecosystem because it

1) consists of many diverse ecosystems

2) is influenced by the anthropogenic factor

3) includes all spheres of the earth

4) constantly uses solar energy

The answer to the tasks in this part (B1–B8) is a sequence of letters or numbers.

In tasks B1–B3, select three correct answers out of six, write down the selected numbers in the table.

B1. The biological significance of meiosis is

1) preventing the doubling of the number of chromosomes in the new generation

2) the formation of male and female gametes

3) formation of somatic cells

4) creating opportunities for the emergence of new gene combinations

5) increasing the number of cells in the body

6) multiple increase in the set of chromosomes

B2. What is the role of the pancreas in the human body?

1) participates in immune reactions

2) forms blood cells

3) is a mixed secretion gland

4) forms hormones

5) secretes bile

6) secretes digestive enzymes

B3. Factors of evolution include

1) crossing over

2) mutation process

3) modification variability

4) insulation

5) variety of species

6) natural selection

When completing tasks B4-B6, establish a correspondence between the contents of the first and second columns. Enter the numbers of the selected answers in the table.

Q4. Establish a correspondence between the plant trait and the department for which it is characteristic.

B5. Establish a correspondence between the structural and functional features of the human brain and its department.

B6. Establish a correspondence between the nature of the mutation and its type.

When completing tasks B7–B8, establish the correct sequence of biological processes, phenomena, and practical actions. Write down the letters of the selected answers in the table.

Q7. Establish the sequence of processes occurring in an interphase cell.

A) mRNA is synthesized on one of the DNA strands

B) a section of the DNA molecule is split into two chains under the influence of enzymes

B) mRNA moves into the cytoplasm

D) protein synthesis occurs on mRNA, which serves as a template.

B8. Establish the chronological sequence in which the main groups of plants appeared on Earth.

A) green algae
B) horsetails
B) seed ferns
D) rhiniophytes
D) gymnosperms

Every person constantly encounters information, and so often that not everyone can explain the meaning of the concept itself. Information is information that is transmitted from one person to another using various means of communication.

There are various ways to transfer data, which will be discussed below.

How information is transmitted

In the process of human development, there is a constant improvement in the mechanisms by which information is transmitted. Methods for storing and transmitting information are quite varied, since there are several systems in which data is exchanged.

There are 3 directions in the data transmission system: transmission from person to person, from person to computer and from computer to computer.

• Initially, information is obtained through the senses - vision, hearing, smell, taste and touch. To transmit information over a short distance, there is a language that allows you to communicate the received information to another person. In addition, you can convey something to another person by writing a letter or during a performance, as well as when talking on the phone. Despite the fact that the last example uses a communication device, that is, an intermediate device, it allows information to be transmitted in direct contact.
• To transfer data from a person to a computer, it must be entered into the device’s memory. Information can take different forms, which will be discussed further.
• Transfer from computer to computer occurs through intermediate devices (flash card, Internet, disk, etc.).

Information processing

After receiving the necessary information, it becomes necessary to store and transmit it. Methods of transmitting and processing information clearly represent the stages of human development.

• At the beginning of its development, data processing involved transferring it to paper using ink, pen, pen, etc. However, the disadvantage of this processing method was the unreliability of storage. If we mention methods of storing and transmitting information, storage on paper has a certain period, which is determined by the service life of the paper, as well as the conditions of its use.
• The next stage is mechanical information technology, which uses a typewriter, telephone, and voice recorder.
• Further, the mechanical information processing system was replaced by an electrical one, because methods of transmitting information are constantly being improved. Such means include electric typewriters, portable voice recorders, and copying machines.

Types of information

The types and methods of transmitting information differ depending on its content. This can be textual information presented orally and in writing, as well as symbolic, musical and graphic. Modern types of data also include video information.

A person deals with each of these forms of information storage every day.

Means of information transmission

The means of transmitting information can be oral and written.

• Oral means include speeches, meetings, presentations, and reports. When using this method, you can count on a quick reaction from your opponent. The use of additional nonverbal means during a conversation can enhance the effect of speech. Such means include facial expressions and gestures. However, at the same time, information received orally does not have long-term effect.
• Written media are articles, reports, letters, notes, printouts, etc. In this case, one cannot count on a quick reaction from the public. However, the advantage is that the information received can be re-read, thereby assimilating the information.

Methods of presenting information

As you know, information can be presented in several forms, which, however, does not change its content. For example, a house can be represented as a word or a graphic representation.

Methods of presenting and transmitting information can be depicted in the following list:

• Text information. It allows you to provide the most complete information, but may contain a large amount of data, which contributes to its poor assimilation.
• A graphic image is a graph, diagram, chart, histogram, cluster, etc. They allow you to briefly present information, establish logical connections, and cause-and-effect relationships. In addition, information in graphical form allows you to find solutions to various issues.
• The presentation is a colorful, visual example of the way information is presented. It can combine both textual data and their graphical display, that is, various types of information presentation.

Concept of communication

Communication is a system of interaction between several objects. In a generalized sense, this is the transfer of information from one object to another. Communication is the key to the success of an organization.

Methods of transmitting information (communication) perform the following functions: organizational, interactive, expressive, incentive, perceptual.

The organizational function provides a system of relationships between employees; interactive allows you to shape the mood of those around you; expressive colors the mood of others; incentive calls for action; perceptual allows different interlocutors to understand each other.

Modern methods of transmitting information

The most modern methods of transmitting information include the following.

The Internet contains a huge amount of information. This allows you to gain a lot of knowledge without bothering with studying books and other paper sources. However, in addition to this, it contains methods and means of transmitting information similar to historically older models. This is an analogue of traditional mail - electronic mail, or e-mail. The convenience of using this type of mail lies in the speed of letter transmission and the elimination of stages of delivery. Today, almost everyone has an email address, and communication with many organizations is maintained precisely through this method of transmitting information.

GSM is a digital cellular communication standard that is widely used everywhere. In this case, spoken speech is encoded and transmitted through a converter to another subscriber. All the necessary information is placed in a SIM card, which is inserted into the mobile device. Today, the presence of this means of communication is a necessity as a means of communication.

WAP allows you to view web pages with information in any form on your mobile phone screen: text, numeric, symbolic, graphic. The image on the screen can be adapted to the screen of a mobile phone or have a look similar to a computer image.

Modern methods of transmitting information also include GPRS, which allows packet data transfer to a mobile device. Thanks to this means of communication, it is possible to continuously use packet data simultaneously by a large number of people at the same time. Among the properties of GPRS are high data transfer speeds, payment only for transmitted information, great possibilities of use, and compatibility parameters with other networks.

The Internet, through the use of a modem, allows you to obtain high speed information transfer at a low cost of such access. A large number of Internet providers creates a high level of competition between them.

Satellite communication allows you to access the Internet via satellite. The advantage of this method is low cost, high data transfer speed, but among the disadvantages there is a noticeable one - the dependence of the signal on weather conditions.

Possibilities of using information transmission media

As new means of information transmission emerge, opportunities arise for unconventional use of various devices. For example, the possibility of video conferencing and video calling has sparked the idea of ​​using optical devices in medicine. In this way, information about the pathological organ is obtained through direct observation during surgery. When using this method of obtaining information, there is no need to make a large incision; the operation can be performed with minimal damage to the skin.

To better understand the process of information exchange and the conditions for its effectiveness, you should have an understanding of the elements and stages of the communication process.

Communication process

In the process of information exchange, one can distinguish four basic elements(Fig. 1.4):

• sender – a person who generates ideas or collects and transmits information;
• message – the actual information encoded using symbols;
• channel – means of transmitting information;
• recipient – the person to whom the information is intended and who interprets it.

Rice. 1.4.

When exchanging information sender And recipient undergo several interrelated stages. The main task of the sender– compose a message and use a channel to convey it in such a way that both parties understand and share the original idea. This is difficult because at each stage the meaning of the message can be distorted or completely lost.

In the process of information movement, its advancement occurs, but the following stages:

• the birth of an idea;
• channel encoding and selection;
• broadcast;
• decoding;
• feedback.

Let us consider the stages of the communication process in more detail in order to show what problems can arise at its different points (Fig. 1.5).

1. The birth of an idea. Information exchange begins with the formulation of an idea or the selection of information. In this case, the sender decides which idea or message should be the subject of exchange. Its role is to provoke and encode information with subsequent transmission to other participants in the process.

It is very important to correctly and carefully formulate your idea so that it becomes interesting and attractive to the recipient. It is important to remember that the idea has not yet been transformed into words or taken on another form in which it will serve the exchange of information. The sender only decided What exactly he wants to convey.

2. Encoding and channel selection. Before transmitting an idea, the sender must encode it using symbols. For example, he may use words, intonation and gestures (body language) as symbols. This coding turns an idea into message.

The sender must also select channel compatible with the character type, used for coding. Some commonly known channels include: speech, written materials, electronic communications including computer networks and email, video tapes and video conferencing. If the channel is not suitable for the physical embodiment of the symbols, transmission is not possible. If the channel is not very consistent with the idea, the exchange of information will be ineffective.

It should be remembered that the choice of communication medium should not be limited to a single channel. It is often desirable to use two or more means of communication in some combination. In this regard, the process becomes more complicated, since the sender has to establish a sequence of use of these means and determine time intervals for transmitting information. However, it is believed that the simultaneous use of means of exchanging oral and written information is usually more effective than exchanging only written information. For example, if at a meeting of department heads, the head of the financial department has proposals to simplify mutual settlements, it would be more effective to present them in writing in the form of handouts, on a screen or flip chart in the form of graphs, diagrams, or videos, accompanying their demonstration with oral comments. At the same time, it is more likely that the information will be perceived, firstly, positively, secondly, completely (or to the maximum extent), and thirdly, the wishes and suggestions of interested colleagues will be promptly taken into account.

• 3. Broadcast. In the third stage, the sender uses a channel to deliver a message (an encoded idea or set of ideas) to the recipient. Here we are talking about the physical transmission of a message, which many people mistakenly take for the communication process itself. At the same time, communication is only one of the most important stages that must be passed through in order to convey an idea to another person.
• 4. Decoding. After the sender transmits a message, the recipient decodes it. Decoding is the translation of the sender’s symbols into the recipient’s thoughts. If the symbols chosen by the sender have exactly the same meaning to the recipient, the latter will know exactly what the sender had in mind when his idea was formulated. If no reaction to the idea is required, the information exchange process ends here.
• 5. Feedback. An exchange of information can be considered effective if the recipient demonstrates understanding of the idea through feedback. For example, he performed the actions that the sender expected from him.

Despite the apparent simplicity of the communication process, it rarely proceeds without interference. There are many potential barriers that stand in the way of effective communications. Factors that disrupt the purity of message transmission are commonly called “noise” in the communication process.

"Noise"- this is any factor that can disrupt the clarity of the transmission of the message at any moment in the communication process.

Sources of noise range from the complexity or imprecision of the message's language to differences in the perceptions of the people receiving it, which can alter the meaning of the encoding and decoding processes. For example, noise is said to occur when messages are poorly encoded (written unclearly) or poorly decoded (not understood), or when communication channels are ineffective (the recipient's attention is diverted from the message). The difference in organizational status between the manager and the subordinate can also be a hindrance, which also makes it difficult to convey information accurately.

Thus, noise in its essence is a barrier in the communication process.

There is always some noise in the communication process, so at each stage of the information exchange process some distortion of meaning occurs. If the noise level is high enough, there may be a noticeable loss of the meaning of the message or even a complete blocking of information exchange.

Rice. 1.5.

Thus, communication process is a sequence of actions when people communicate. Purpose of the communication process– ensuring understanding of the information being exchanged. The communication process has certain elements and occurs in stages. At each stage, “noise” (interference in communications) may occur, which can significantly reduce their effectiveness.

As noted above, the main goal of communication is the exchange of various types of information. Each enterprise is penetrated by a network of information channels that are designed to collect, analyze and systematize it. At the same time, in many cases, a manager can choose and use the most convenient channels of communication with other managers and subordinates. For example, you can discuss a problem in a personal conversation or over the phone; It is permissible to convey information to employees by writing a note or letter, or posting a message on a notice board. The specific channel is largely determined by the nature of the message (Fig. 1.6).

Communication channels are classified according to their capacity.

Channel capacity is the amount of information that can be transmitted through it in one communication episode.

In general, communication becomes more effective when using a variety of channels, both written and oral.

The capacity of communication channels is affected by three factors:

• ability to process multiple signals simultaneously;
• the ability to provide fast, two-way feedback;
• ability to provide a personal approach to communications.

From the point of view of these possibilities, the best remedy is personal communication. Only it guarantees direct impact, transmission of multiple information signals, immediate feedback and personal approach.

Telephone communication or through other electronic means speeds up the communication process, but lacks the “presence effect”.

Personal written messages - notes, letters, comments - can also have a personal orientation, but they convey only words written on paper and cannot provide quick feedback.

Impersonal communication channels - bulletins, standard computer reports - are the smallest, their bandwidth is limited to the greatest extent.

Essentially, the effectiveness of a communication method depends on how suitable it is for the information that needs to be conveyed. In particular, research has shown that when information is ambiguous (i.e., needs clarification), oral communication is more effective than written communication. However, written communication is more effective when the information is obvious, simple and straightforward. For example, communicating work assignments to employees, informing them about decisions made, or consolidating previously reached agreements in writing.

In any case, the important question is not only which form of communication to choose, but also how to use it correctly. In table 1.1 provides some useful tips for using traditional means of communication.

• Cm.: Daft R.L. Leadership lessons.
• Cm.: Daft R.L. Leadership lessons.
• Greenberg J., Baron R. Organizational behavior: from theory to practice. M., 2004. P. 441.