What is a fetus? This term can be found both in zoology and in botany. Now a little more about each.
Zoology
In this section, the embryo is understood as an embryo. What is a fetus? Let us examine chicken and eggs as an example. Where does embryo development begin? From the moment of fertilization. In this case, the yolk enters the oviduct. Then, twenty hours later, when the egg was dressed in all the shells, an embryo formed inside, the chicken will blow it.
Note that in order for the chicken to appear, it is necessary to maintain a constant egg temperature (forty degrees). The embryo is alive for no more than three weeks, if the chicken has not hatched during this period, the embryo dies. How to keep the desired temperature? For this, there are artificial devices or a hen-hen itself, which will hatch eggs until offspring are born.
Botany
What is a "germ" in botany? As in zoology, it can be called an embryo that arose as a result of the fusion of two gametes (male and female) during sexual reproduction. In higher plants, the germ is called the germ of the asexual sporophyte.
Structure
So, what is the embryo of a plant, sorted out, now a little about the structure. It consists of several parts:
- Spine, from which the main root will subsequently develop.
- The germinal stem is just that part of the plant that we first see on the surface of the soil during seed germination.
- The kidney from which the shoot emerges.
- Cotyledons are the first leaves of a plant that begin their development in the seed. As a rule, these leaves are different from those of an adult plant. Moreover, the difference can be found not only in form and structure, but also in functions.
How does seed germination occur?
Germination is possible only when certain conditions are reached. For the development of the body, a sufficient amount of heat, light and moisture is necessary. Due to the activity of the cells of the future plant, the development of the main organs begins in the seed. The first spine appears, which secures the grain in the soil. Then the stem develops, after which the cotyledons begin their development. If the previous steps are the same for all plants, the development of the cotyledon is different for everyone. They can remain underground and perform the function of enrichment with nutrients, and can be carried to the surface along with the stem and perform the function of the first leaves, that is, engage in photosynthesis.
After this, the main leaves begin to develop, the root, which together with all the branches forms the root system. There are internodes and subordinate roots.