When a lineage splits into multiple line of descents, then, it leads to speciation. It is a process by which a single population evolves into different species. The process of speciation leads to the development of two or more species as the lineages are splitted. These two evolved species are genetically independent.
Hence, the blank can be filled with 'speciation'.
<u>Answer:</u>
<em>Six centromeres are observed in a prophase cell from an insect, there are </em><u><em>20 pairs of chromosomes present</em></u><em>. </em>
<u>Explanation:</u>
<em>Centromeres is defined as the part of the DNA</em> which are held responsible for the directional changing of chromosomes.
And these chromosome gets divided into <em>2 daughter cells while undergoing the process of mitosis and meiosis. </em>
<em>Chromosome is basically defined as a thin structure</em> as of a threadlike which is made out of nuclei acid and protein which is <em>located at the nucleus of various living cells</em>
3:they are usually microscopic