<span>Homologous chromosomes are chromosomes of equal length, size, and of corresponding genetic material. If, during meiosis, these chromosomes divide improperly, when they are re-combined with the opposite sex's portion, they will combine improperly. The unequal distribution of genetic material in reproduction will eventually create what's call an aneuploid germ cell: this germ cell results in dead zygotes, which leads to a miscarriage or spontaneous abortion in about 25 percent of all conceptions. So we see that it is imperative the genetic material of these chromosomes be exactly where it is supposed to be: so that it can combine perfectly with its compliment.</span>
The answer is that the criteria of classification change with the improved understanding of organisms around us. During the time of Aristotle, not much was known about the living organisms. So, he classified them as he observed. Plants were classified into herbs, shrubs and trees; very much like what’s taught to a second grade student. Animals as Enaima and Anaima based on the presence or absence of RBCs. After him, Carolus Linnaeus tried his hand over classification. He came up with the 2 kingdom classification: Plants and Animals. He considered only a set of morphological and physiological criteria to decide the kingdom to which an organism belongs. It includes presence of cell wall, mode of nutrition, contractile vacuole, locomotion and others. Based on these criteria, he included widely differing organisms into a single kingdom, for example, fungi, bacteria, algae, and higher plants were included into plant kingdom just because they have cell wall as a common aspect. Then came, Ernst Haeckel, who came with a third kingdom of Protista to include unicellular organisms. Copeland gave a 4 kingdom classification segregating unicellular organisms into 2 separate kingdoms based on their nuclear structure. R.H. Whittaker came next introducing the most accepted 5 kingdom classification system. You should understand one thing that man’s knowledge of classifying organisms improved with the improving technologies available to him, which he exploited to very effective extent. Carl Woese gave the 6 kingdom classification and 3 domain system based on the 16S rRNA sequence.
Our understanding of organisms around us is improving day by day and the system of classification will also change further in pace with the improvement in technology.
I hope this helps! :D]
~ Kana ^^
They produce oxygen they are used as shelter, they are used for blocking the shade, they sustain other animals that sustain the planet and us.
A. Vili in stomach. And this is because of gluten.
Answer:
D
Explanation:
because the sun is energy