What development is called postembryonic? Postembryonic period

Few people think about the fact that every stage of life has its own name. So, science knows embryonic and postembryonic development. These periods are very different from each other and have different characteristics. The article will discuss what kind of development is called postembryonic development. You will learn the types of this period and features.

What development is called postembryonic?

The moment when the embryo leaves the fetal membrane is a transitional from the embryonic period to the postembryonic period . In the people this time is called birth. It is worth noting that in different living organisms this process is very different.

Types of development of a living organism

The post-embryonic period can be characterized by two kinds of development. Science knows the direct and indirect transformation of a living organism.

Direct development

This type of transformation involves an organism that is very similar to an adult. Thus, postembryonic development of a person has a direct form. This also includes the development of animals and some reptiles.

After the birth of the embryo is very much like an adult organism. However, it differs in size and lack of skills.

Indirect development, or metamorphosis

The post-embryonic period may have an indirect form (metamorphosis). In this case, an organism appears from the membranes of the membranes, which differs greatly from the adult. This includes some invertebrates, mollusks and reptiles. As an example, you can take a butterfly. Postembryonic development of the organism in this case is characterized by being in the form of a larva. Only then the butterfly becomes like an adult.

Characteristics of the postembryonic period (direct development)

As already mentioned above, right after the new organism leaves the membranes, a new stage in development begins. The post-embryonic development of man is divided into several stages. The final stage is puberty. Let us consider the main stages of the postembryonic period.

The first stage of development: from birth to six months

At this stage, the baby adapts to the new environment. He learns to hear and focus his view on certain things. The food at this stage of development is exceptionally liquid. The kid can not eat adult food by himself and depends entirely on the mother. Some children are faster in development than others. They move to the next degree of the postembryonic period faster. So, some kids in half a year can already stand, sit and crawl. However, these are only physical skills. Science still does not know the case when the child at this stage began to speak a clear adult language.

It is worth noting that many animals and reptiles that pass the direct path of postembryonic development live in much the same way. However, they can pass this period much faster than a person.

The second stage of development: up to one year

At this stage, the little man learns to sit crawl and walk. This stage is characterized by the acquisition of physical skills. Also, the young organism begins to gradually become accustomed to new food. Many children begin to make new sounds at this stage. So they learn to speak in a language understood by an adult. If a child develops faster, at this stage he can already speak some words or even simple sentences.

Reptiles and animals in this period are already fully ready for adulthood. They themselves can get their own food and are no longer dependent on adults.

The third period: growth and training

The human body is characterized by the longest postembryonic development. At this stage, the child can already fully support himself, but to live without parents is still very difficult for him. In ordinary life children at this level attend pre-school, and then school establishments. They grow, develop and learn everything that is useful to them in their adult life.

Mammals and animals at this stage have already completely passed the postembryonic period and are considered adult individuals.

Fourth period: puberty

So, what kind of development is called postembryonic, you already know. In humans, it ends in about 16-20 years. At this stage important parts of the body begin to work. The pituitary and adrenal glands produce certain hormones. Women begin to function as ovaries and menstruation appears. Men also acquire sexual maturity and are able to continue their generation.

The postembryonic period ends with the transition to adulthood. A person is already able to live independently and create his own family.

Characteristics of indirect postembryonic development

As in the previous case, this development is divided into several main stages. Let's consider them in detail.

The first stage: after birth

Immediately after the organism leaves the fetal membranes, its further transformation begins. At this stage, the new individual is completely different from the adult. It is very different in appearance and internal development.

The second stage: transformation

At this stage, there is a strong transformation of a new organism. Every kind of living creature has it in different ways. The individual looks like an adult animal or mammal. However, many organisms at this stage still need care and protection. They can not provide themselves for the time being.

The third stage: the acquisition of skills

Indirect postembryonic development has a final stage, which is characterized by the acquisition of certain skills. They will help the future organism to live independently and not depend on extraneous individuals.

Summing up and conclusion

Now you know what kind of development is called postembryonic. It is worth noting that the indirect transformation occurs much faster than the direct postembryonic period.

The person undergoes the longest course of this stage. However, human skills can survive even in the most difficult conditions. This can not be said of reptiles or animals. Behind the development of a person in the postembryonic period, some doctors watch: a pediatrician, a neurologist and others. Parents' parents are also especially attentive.

Everyone should know what the post-embryonic period is. Initial data about this time are known from the lessons of biology. It is this kind of information that helps to develop your own world.