Crossing over does not occur during prophase II; it only occurs during prophase I. In prophase II, there are still two copies of each gene, but they are on sister chromatids within a single chromosome (rather than homologous chromosomes as in prophase I).
Does crossing over occur in mitosis 1 or 2?
Crossing over does not occur in mitosis. Explanation: Mitosis is cellular cloning. This means that Mitosis ends with two identical cells; no variation.
Why is crossing over not possible in meiosis II?
Why is crossing over not possible in meiosis II? … Because prophase only occurs in meiosis I.
What 4 things happen during prophase?
- chromosomes condense and become visible.
- spindle fibers emerge from the centrosomes.
- nuclear envelope breaks down.
- nucleolus disappears.
What could have happened if there is no crossing over in prophase 1 of meiosis 1?
If crossing over did not occur during meiosis, there would be less genetic variation within a species. … Also the species could die out due to disease and any immunity gained will die with the individual.
Does crossing over occur in mitosis yes or no?
It was a surprise for geneticists to discover that crossing-over can also occur at mitosis. Presumably it must take place when homologous chromosomal segments are accidentally paired in asexual cells such as body cells. … Mitotic crossing-over occurs only in diploid cells such as the body cells of diploid organisms.
What is the result of crossing over?
During crossing over, part of one chromosome is exchanged with another. The result is a hybrid chromosome with a unique pattern of genetic material. Gametes gain the ability to be genetically different from their neighboring gametes after crossing over occurs.