Since homologous chromosomes are not identical and do not originate from the same organism, they are different from sister chromatids. Sister chromatids result after DNA replication has occurred, and thus are identical, side-by-side duplicates of each other.
Why do chromosomes appear as double structure?
Because all 46 chromosomes replicate before cell division in what we call S phase. After S phase is complete they condense into dense structures and replicated chromosomes(aka sister chromatids) are joined at the hip (aka centromere) before mitotic spindle assembly pulls them apart into different cells.
Why do chromosomes appear as double structures just before mitosis occurs?
It is important that the chromosomes are doubled before mitosis because each of the two resulting daughter cells must have the same amount of DNA as…
Why does each chromosome have to become two strands before the cell divides?
The single strand of DNA that makes up each chromosome produces an exact copy of itself. … In mitosis, the chromosome copies separate, the nucleus divides and the cell divides. This produces two cells called daughter cells . Each daughter cell is genetically identical to the parent cell and to one another.
Can a chromosome have one chromatid?
When fully condensed, replicated chromosomes appear as thick X-shaped structures that are readily observed under the microscope (see figure below). Chromosomes can have 1 or 2 chromatids, depending on whether they have replicated.
How many chromosomes did each of your daughter cells contain?
At the end of mitosis, the two daughter cells will be exact copies of the original cell. Each daughter cell will have 30 chromosomes. At the end of meiosis II, each cell (i.e., gamete) would have half the original number of chromosomes, that is, 15 chromosomes. 2.
How many chromosomes are created when DNA replicates?
Once mitosis is complete, the cell has two groups of 46 chromosomes, each enclosed with their own nuclear membrane. The cell then splits in two by a process called cytokinesis, creating two clones of the original cell, each with 46 monovalent chromosomes.