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
Explanation:
potential energy is highest at its highest point
The answer is <span>a) cancer.
</span><span>Cells must control mitosis (cell division) in order to maintain normal cell function. If something happens to the control of mitosis, the healthy cells will divide uncontrollably. These new cells are cancer cells and they are also out of control. They will continue to divide uncontrollably, so the mass of the cancer cells will grow.
</span>Regarding other choices:
- cystic fibrosis is an inherited disorder of lungs and digestive system,
- albinism is a congenital disorder characterised by the absence of pigment in the skin and hair,
- meiosis is cell division resulting in the reduction of a chromosome number in half.
The cell cycle is controlled by many cell cycle control factors, namely cyclins, cyclin-dependent kinases (Cdks) and cyclin-dependent kinase inhibitors (CKIs). Cyclins and Cdks, which are positive regulators of the cell cycle, activate cell cycle factors that are essential for the start of the next cell cycle phase.
Answer:
Mitosis
Explanation:
Mitosis is a process of nuclear division in eukaryotic cells that occurs when a parent cell divides to produce two identical daughter cells
