what causes a shortage in economics
What Causes A Shortage In Economics? A shortage, in eco...
In eukaryotes, the cell cycle consists of four discrete phases: G1, S, G2, and M. The S or synthesis phase is when DNA replication occurs, and the M or mitosis phase is when the cell actually divides. The other two phases — G1 and G2, the so-called gap phases — are less dramatic but equally important.
In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells, each with half the number of chromosomes as the original parent cell. The two meiotic divisions are known as meiosis I and meiosis II.
The centromere serves as the site for kinetochore assembly and therefore it is essential during the alignment of the chromosomes at the metaphase plate and the subsequent segregation of chromosomes during cellular division. The presence of the centromere results in the characterization of the chromosomal arms.
In humans, several chromosomes are submetacentric: chromosome 2, chromosome 4, chromosome 5, chromosome 6, chromosome 7, chromosome 8, chromosome 9, chromosome 10, chromosome 11, chromosome 12, chromosome 17, chromosome 18 and X chromosome.
Centromeres are the point at which two replicated sister chromatids are attached and only appear when DNA replication occurs. Meaning that the normal number of chromosomes in the cell should be 10 and there should normally be 5 chromosome pairs.
Centromeres play essential roles in equal chromosome segregation by directing the assembly of the microtubule binding kinetochore and serving as the cohesion site between sister chromatids.
Functional mapping of a trypanosome centromere by chromosome fragmentation identifies a 16-kb GC-rich transcriptional “strand-switch” domain as a major feature. Genome Res.
what is a centromere
what is a chromatid