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: A. The onion cells have lysosomes, and the cheek cells do not.
Explanation:
Answer and Explanation:
Protein is one of the most important molecules in our organism, being present in the composition of all elements, in addition to participating in several metabolic processes. This importance creates the need to study this molecule, however, to study it it is necessary to know the composition chemistry and the levels of structure it presents.
The chemical composition of proteins is related to amino acids, since protein is formed by them. In this case, we can say that the proteins have the same composition as the amino acids containing carboxylic acid and different amino groups, which is what determines the name and function of the amino acid.
In addition to chemical composition, the structure levels of proteins are extremely important, as they only function at a specific structural level. As for these levels, proteins can have a primary structure (there are more than two amino acids organized in a linear row), a secondary structure (when the primary structure turns into a helix species), a tertiary structure (formed by a more intense folding of the secondary structure providing the appearance of helices and leaves) and quarternary structure (when several tertiary structures are joined, allowing folding at the three-dimensional level. This is the functional structure of the protein).
Answer: the tendency toward a relatively stable equilibrium between interdependent elements, especially as maintained by physiological processes.
Explanation: one of the most familiar examples of homeostasis Body temperature control in humans
plz mark brianliest
It’s funny because the concept of sustainability is thought to come from field of forestry. Around the year 1700, Carl von Carlowitz described the concept of sustainable forestry.
