Technology of storage and primary processing of agricultural products

6. Population - a species - a set of organisms belonging to the same species with the same habitat, forming a system of higher order populations from the organism.
7. Biogeocenosis - a set of organisms with different levels of complexity and belonging to different species. The main function of biogenesis is the accumulation and redistribution of energy.
The biosphere is the highest level of living structure. It distinguishes between living and non-living. The sum of all living organisms. At this level, the circulation of substances and energy takes place.
Questions for self-examination
1. What are the molecular, subcellular, and cellular levels of life?
2. What are the tissue, organ, and organism levels of life?
3. What is the description of population and species levels of survival?

7 LABORATORY WORK.

Topic: The study of chromosome morphology

The purpose of the work. Get acquainted with the structure and types of chromosomes. It consists of studying the state of chromosomes in somatic and germ cells and the set of chromosomes in different organisms.
The content of the work. Each plant and animal species has a constant number and shape of chromosomes. Usually the chromosome structure is studied during the metaphase (the thickest of them) of mitotic division. During this period, each chromosome consists of two chromatids . The cluster of chromatids is called the centromere or first bond. A chromosome is a chromosome dye, and a soma is a body, that is, a body that is dyed. The chromosome is rod-shaped and consists of two parts, the shoulders and the centromere.

Figure 3
The centromere can be located in different parts of the chromosome, and the shape of the chromosome also varies depending on the condition of the centromere . If the centromere is located between the chromosomes, such a chromosome is called equal shoulder or metacentric . Slightly unequal shoulder chromosomes are called slightly unequal shoulder or submetacentric . If the centromere is located on one side of the chromosome, it is called an unequal shoulder or acrocentric chromosome. If the centromere is located at the end of the chromosome, it is called a rod- shaped or telocentric chromosome. Some chromosomes may have a second link and a (satellite) satellite. Experiments by scientists have shown that when a part of a chromosome's shoulder is cut off, the chromosome survives, and the cut part can be attached to the end of another chromosome or melt away. The fact that chromosomes have different shapes can be caused by such natural mutations. The loss or addition of a part of a chromosome leads to a change in the traits that control the chromosome.
When viewed under a microscope , chromosomes look different in shape and size. It can be believed that the chromosomes in each cell (contained in each cell) consist of a pair of similar chromosomes. Such identical chromosomes are called homologous chromosomes.


Figure 4
The sum of such pairs of chromosomes forms a diploid set , and they are denoted by “2n” . The number of chromosomes in germ cells is twice less than in somatic cells , so it is called the haploid set and is denoted by “n” . Each homologous pair of chromosomes differs from the other in its shape, size, and satellite chromosomes . This means that the chromosomes of each biological species can be characterized by their number, shape and specific structure. Depending on the traits shown, the specific set of chromosomes in a somatic cell is called a karyotype.
Table 1
Karyotype of cultivated plants

Plants	In the germ cell	In the somatic cell	Plants	In the germ cell	In the somatic cell
Cabbage	9	18	White mulberry	14	28
Ordinary beets	9	18	Grapes	19-28-38	38-57-76
Bodiring	7	14	Carrots	9	18
Cherry	16	32	Potatoes	24	48
Plum	24	48	Tomatoes	12	24
Apricot	8	16	Garimdori	24	48
Peaches	8	16	Don't	17-25	34-51
Soft wheat	21	42	Durum wheat	14	28
Nok	17	34	Barley	7	14
Beda	8-16	16-32	Suli	21	42
Peas	7	14	Cotton	13-26	26-52
Cherries	8	16