Answer:
1. They must be removed before sister chromatids or homologous chromosomes can separate
Explanation:
During the S-phase of the cell cycle, not only does DNA have to be replicated, but also newly synthesized DNA molecules have to be connected with each other. This replicated DNA (sister chromatids) remain physically connected with each other from S phase until metaphase. This physical connection is called Sister chromatids cohesion.
Sister chromatid cohesion depends on COHESIN, a tripartite protein complex that forms a ring structure to hold sister chromatids together during mitosis and meiosis. Cohesin regulates the separation of sister chromatids during cell division, either mitosis or meiosis. This sister chromatid cohesion is essential for the biorientation of chromosomes on the mitotic or meiotic metaphase spindle, and is thus an essential prerequisite for chromosome segregation. Without the cohesion, sister chromatids would not be segregated symmetrically between the forming daughter cells, resulting in aneuploidy.
Cohesion is established during S-phase of DNA replication, and the cohesins hold the sister chromatid together after DNA replication until anaphase when the removal of cohesin leads to separation of sister chromatids (meiosis II and mitosis) and homologous chromosomes (meiosis I).
Answer:
The earth system usually refers to the different ways in which various physical, chemical as well as the biological processes interacts with one another and it includes the land areas, oceans, atmosphere, minerals and also the different cycles such as carbon, nitrogen, sulfur and so on.
These processes are continuously taking place at, on and below the surface of the earth, maintaining an equilibrium. The life existing on earth is directly dependent on these conditions and on-going processes. When there occurs changes in these conditions, then the lives on earth are affected.
For example, the lives are dependent on the climatic conditions, and when suppose the concentration of green house gases and other toxic elements are increased in an ecosystem, then the temperature will eventually rise, and there reaches a point when it becomes difficult for life to sustain. The organisms will suffer from different diseases.
Thus, the growth of life on earth affects when there occurs changes in the earth's system.
One of the changes in development and specialization that did not happen in primitive mammals was the increase in stomach capacity. The specialization of teeth and the lower jaw are two important modifications of the primitive mammals. Also an increase in size and brain capacity are two crucial modifications of the early mammals.
The correct answer for this question is this: "Species diversity measures the number of species in the biosphere, while genetic diversity measures the variety of genes in the biosphere, including genetic variation within species."
<span>Species diversity and genetic diversity are different in terms of what the two terms measure.</span>
Hey there!
I believe the answer you're looking for is radio wave
Hope this helps!
