Genetics is a science that studies the laws of heredity and variability of all living things. It is this science that gives us knowledge about the number of chromosomes in different species of organisms, the size of chromosomes, the location of genes on them, and how genes are inherited. Genetics also studies mutations that occur during the formation of new cells.
Chromosome set
Every living organism (except bacteria) has chromosomes. They are located in each cell of the body in a certain amount. In all somatic cells, chromosomes are repeated twice, thrice or more times, depending on the type of animal or plant variety. In germ cells, the chromosome set is haploid, that is, single. This is necessary so that when the two germ cells merge, the correct set of genes for the body is restored. However, in the haploid set of chromosomes are also concentrated the genes responsible for the organization of the whole organism. Some of them may not appear in the offspring if the second reproductive cell contains stronger signs.
How many chromosomes does a cat have?
You will find the answer to this question in this section. Each type of organism, plant or animal, contains a specific set of chromosomes. Chromosomes of one species of creatures have a certain length of a DNA molecule, a specific set of genes. Each such structure has its own size.
How many chromosomes do cats and dogs have - our pets? The dog has 78 chromosomes. Knowing this number, is it possible to guess how many chromosomes a cat has? It’s impossible to guess. Because there is no relationship between the number of chromosomes and the complexity of the organization of the animal. How many chromosomes does a cat have? There are 38 of them.
Chromosome Size Differences
A DNA molecule, with the same number of genes located on it, in different species can have different lengths.
Moreover, the chromosomes themselves are of different sizes. One information structure can contain a DNA molecule long or very short. However, chromosomes are not too small. This is due to the fact that when the daughter structures diverge, a certain weight of the substance is necessary, otherwise the divergence itself will not occur.
The number of chromosomes in different animals
As mentioned above, there is no relationship between the number of chromosomes and the complexity of the organization of the animal, because these structures have different sizes.
How many chromosomes a cat has, the same number of other feline cats: a tiger, a jaguar, a leopard, a cougar and other representatives of this family. Many canines have 78 chromosomes. The same is for domestic chicken. The domestic horse has 64, and the Przhevalsky horse has 76.
A person has 46 chromosomes. The gorilla and chimpanzee have 48, while the macaque has 42.
The frog has 26 chromosomes. In the somatic cage of the pigeon there are only 16. And in the hedgehog - 96. In the cow - 120. In the lamprey - 174.
Next, we present data on the number of chromosomes in the cells of some invertebrate animals. The ant, like the roundworm, has only 2 chromosomes in each somatic cell. The bee has 16. The butterfly has 380 such structures in the cage, and radiolarians have about 1600.
Animal data show different numbers of chromosomes. It should be added that Drosophila, which geneticists use during genetic experiments, has 8 chromosomes in somatic cells.
The number of chromosomes in different plants
The plant world is also extremely diverse in the number of these structures. So, peas and clover each have 14 chromosomes. Onions - 16. Birch - 84. Horsetail - 216, and fern about 1200.
Differences between males and females
At the genetic level, males and females differ in only one chromosome. In females, this structure looks like the Russian letter "X", and in males as "Y". In some animal species, females have a "Y" chromosome, and males have an "X".
The characters found on such non-homologous chromosomes are inherited from father to son and from mother to daughter. The information that is fixed on the Y chromosome cannot pass to the girl, because a person who has this structure necessarily has a male gender.
The same applies to animals: if we see a three-colored cat, we can say for sure that we have a female.
Because only in the X chromosome belonging to the females does the corresponding gene exist. This structure is the 19th in the haploid set, that is, in germ cells, where the number of chromosomes is always two times less than in somatic ones.
The work of breeders
Knowing the structure of the apparatus that stores information about the body, as well as the laws of inheritance of genes and the features of their manifestation, breeders derive new varieties of plants.
Wild wheat often has a diploid set of chromosomes. There are not many wild representatives with a tetraploid set. Cultivated varieties often contain tetraploid and even hexaploid sets of structures in their somatic cells. This increases yield, weather resistance, and grain quality.
Genetics is an entertaining science. The device apparatus containing information about the structure of the whole organism is similar in all living beings. However, each type of creature has its own genetic characteristics. One of the characteristics of the species is the number of chromosomes. Organisms of one species always have a certain constant amount.