In this paper, we propose to distinguish the difference between ovogenesis and spermatogenesis, to talk about these processes themselves. Of course, we will not disregard the sex cells, we will explain in detail their structure and functions.
Reproduction is the main purpose of all living beings of our planet, it helps to continue the race, that is, our planet will never be empty. On the contrary, now the number of living beings, especially people, is growing exponentially. The egg and sperm are the sex cells of women and men, respectively. They will be the subject of our article. Gametogenesis refers to the process of formation of germ cells. If we are talking about spermatozoa, then it is called spermatogenesis, if about eggs, then ovogenesis. You will learn all this in more detail below.
Gametogenesis
Ovogenesis and spermatogenesis, the difference between which is uncritical, are very similar in many features, can be called one general term - "gametogenesis". Now about this a little more.
To begin with, we will analyze the concept itself, we can distinguish two words: "gamete" and "genesis", the latter from the Greek language can be translated as "origin". That is, literally, the term "gametogenesis" means "the origin of gametes." Gametes are germ cells, in men - sperm, in women - eggs. Gametogenesis itself can also be divided by gender: the gametogenesis that occurs in the male body is called spermatogenesis, and in the woman’s body - ovogenesis. But here we come to the first difference between these processes. Ovogenesis begins even before the birth of a girl, and spermatogenesis is manifested in boys who have reached a certain age, usually 12-13 years.
Puberty girls
The process of egg formation, i.e. ovogenesis, occurs even in the womb, while puberty, or rather its first stage, takes about nine years. We offer a little more detail to consider the stages of puberty girls:
- 1st stage - increased growth, there are cases when a girl is gaining more than 10 centimeters in height, this is considered the norm. As a rule, now girls overtake boys.
- 2nd stage - a change in secondary sexual characteristics. At about age 12, the girl begins to emerge from the image of the ugly duckling. The breast begins to grow, the waist decreases, hair grows in the pubic area and in the armpits. At about this stage, canned eggs wake up and begin their further development. Soon the girl will find out what menstruation is.
- 3rd stage - the final stage. He accounts for about 18 years. Now the girl is considered fully formed, she can reproduce healthy offspring.
Puberty boy
As we mentioned earlier, in girls eggs are formed in the womb, in boys everything is a little different. Sperm cells begin to develop only when they reach 12-14 years. Before this stage of puberty, there are also changes:
- penis enlargement;
- enlargement of the scrotum;
- pubic hair, in the armpits, on the legs and face.
Upon reaching 12-14 years, the young man can already begin to have a sexual life, but his parents should warn him, because he can already cause an unwanted early pregnancy of his companion. Now we turn directly to male and female reproductive cells, consider their structure, stages of formation, similarities and differences.
Egg
Let's start with female germ cells, the characteristic of ovogenesis will be examined by us a little later. To begin with, we suggest considering the structure and function of the egg.
The egg is a relatively large and motionless cell; its size reaches 170 microns, which is much larger than male germ cells (up to 70 microns). Each of them contains the necessary nutrients, there we will see:
- substances needed for protein biosynthesis;
- regulatory substances;
- yolk.
Cells can be divided by the amount of yolk:
- on alecitic;
- polycytal;
- mesocytal;
- oligolecital.
From a negligible amount to a very large amount, respectively. If we consider the female egg, then it can be attributed to the alecital and isolecitic type. That is, there is little yolk in it, which can be explained by the fact that the human embryo quickly passes to the hematotrophic type of nutrition. Isolecital type means that the yolk is evenly distributed and the core is in the center.
The egg has the following membranes:
- cytoplasm;
- protective shell;
- radiant crown.
All membranes have a protective function, prevent more than one sperm, which is necessary for fertilization, from entering the egg. All others are blocked.
Now select the functions of the egg:
- providing the embryo with energy;
- provision of nutrients at the initial stage of the embryo.
Sperm
Everyone knows that a sperm is a male reproductive cell, but how is it arranged? We suggest a little discussion of this issue. You can see the appearance of gametes in the photographs of this section. In its structure, the following parts can be distinguished:
- head;
- neck;
- middle part;
- tail.
The sperm head is filled with a nucleus, it is she who carries hereditary information. During fertilization, the egg misses it. The gender of the unborn child depends on the sperm. If he carries the X chromosome, then there will be a girl, if Y, then a boy.
The cervix is presented in the form of a small narrowing in front of the middle part of the sperm, this part is responsible for the active movement, otherwise fertilization would be impossible.
Next is the body, which also produces energy for the movement of the gamete. The tail is represented by a flagellum, which performs a very important task - movement.
Before we consider the features of spermatogenesis and ovogenesis, we propose to highlight the main function of spermatozoa - this is the delivery of genetic material to the egg.
Ovogenesis
We start with the formation of a female reproductive cell, identify periods of ovogenesis and characterize each of them. So, the phases are distinguished:
- breeding;
- growth;
- ripening.
Now we can already name the first difference between ovogenesis and spermatogenesis: in the first case, female germ cells (ova) are nucleated, and in the second - male (spermatozoa). Let's characterize each stage of ovogenesis.
At the stage of reproduction, the initial cells (germ cells) present in the parenchyma divide by mitosis. Thus, the accumulation of ovogony occurs in the cortical layer of the ovaries. They accumulate:
Now they are very different from their predecessors, the resulting ovogony is much larger than the primordial, but their genetic composition is identical. It is important to note that this process occurs even before the birth of the girl, that is, in the womb.
The next stage occurs shortly before the birth of the girl. This stage is called growth. Now mitosis is dividing, so first-order oocytes are formed. Compared with ovogony, they become smaller, but then quickly increase in size. Now oocytes will face a slight difficulty, they will be captured by the granular membrane and stop developing at the stage of the primordial follicle. In total, there are approximately two million such cells, but only some of them will receive further development (approximately 450).
The third stage (maturation) occurs shortly before the appearance of the first menstrual girls. One of the sleeping follicles wakes up and continues its development, which stopped about 12-13 years ago.
Spermatogenesis
We have already singled out one difference between ovogenesis and spermatogenesis (various germ cells develop), from the read, we can also distinguish that ovogenesis begins even before the birth of the girl, but the spermatogenesis process - when the child reaches 12-14 years of age. We have already identified two differences, then we will once again denote this to consolidate knowledge.
The stages of spermatogenesis are also slightly different from the stages of ovogenesis (the presence of another stage). The following stages of spermatogenesis are distinguished:
- reproduction;
- height;
- maturation;
- formation.
Here we see the similarity of these processes, the first three stages are the same, only at the maturation stage, ovogenesis ends, and spermatogenesis continues, the formation stage begins.
Differences
You have almost finished reading this article, try it yourself - what are the differences between spermatogenesis and ovogenesis. Now check how you did the job.
The first difference between ovogenesis and spermatogenesis is the different start time of the process. In girls, the process of gametogenesis begins during fetal development, in boys - at 12-14 years.
The second difference is that in the process of ovogenesis, eggs develop, and spermatogenesis develops spermatozoa.
The third difference is the life span of germ cells. The sperm lives from one hundred to one hundred and ten days (given the entire process of spermatogenesis, approximately 74 days), the female reproductive cell is the result of a long wait in the ovary (from 12 to 40 years).
The fourth difference is quantity. Over the course of a man’s life, many hundreds of billions of spermatozoa come into the world, and approximately 450 eggs pass completely all stages of ovogenesis.
Similarities
During the writing of the article, we highlighted the similarities and differences between spermatogenesis and ovogenesis. Now we will generalize once again, denote it as a list of similarities of these processes.
- Three general stages (reproduction, growth, maturation).
- Spermatocytes and oocytes are formed by mitosis.
- The growth stage in both ovogenesis and spermatogenesis is characterized by an increase in gametes.
- The ripening phase occurs through meiosis.