Gynandromorphs
The term "gynandromorph" literally means part female (gyn-) and part male (andro-). You might ask how such a thing can happen -- well, here's the answer. Stick with me here, as this requires some significant explanation!!
All sexually reproducing organisms begin existence as a single cell, a zygote, which is a fused sperm and egg cell. This cell then divides and divides, eventually making all the different cells in the body. During the process of cell division, some cells obviously become different from others (a process called differentiation) and ultimately a cell's development becomes determined at some point, that is, it enters a developmental pathway that determines what it will become (a muscle cell, a nerve cell, a cell lining the intestine, etc.).
In humans, the earliest cell divisions are indeterminate, which means that the developmental pathway is still flexible for all of the cells. An interesting side benefit of this is that, if one of these early cells happened to be destroyed, the end result is that it has virtually NO effect on development, since the other cells are still "flexible" in what they can become.
On the other hand, each cell division in insects, from the zygote on, is completely determinate, which means that decisions about what a cell will become are made with each division. The decisions that are made with the earliest cell divisions are as follows:
First division (of zygote) -- determines left and right sides
Second division -- determines front and back (at this point, there would be four cells, a front left, a front right, a back left and a back right)
Third division -- determines top from bottom (at this point, there would be eight cells, a front upper left, a front lower left, and so on)
Just to follow up on what I said about humans, if an insect cell were to be damaged after the third division, say the lower back right cell, you would end up with seven-eighths of an insect (missing the back lower right part of the abdomen, for instance) if development coul
The term "gynandromorph" literally means part female (gyn-) and part male (andro-). You might ask how such a thing can happen -- well, here's the answer. Stick with me here, as this requires some significant explanation!!
All sexually reproducing organisms begin existence as a single cell, a zygote, which is a fused sperm and egg cell. This cell then divides and divides, eventually making all the different cells in the body. During the process of cell division, some cells obviously become different from others (a process called differentiation) and ultimately a cell's development becomes determined at some point, that is, it enters a developmental pathway that determines what it will become (a muscle cell, a nerve cell, a cell lining the intestine, etc.).
In humans, the earliest cell divisions are indeterminate, which means that the developmental pathway is still flexible for all of the cells. An interesting side benefit of this is that, if one of these early cells happened to be destroyed, the end result is that it has virtually NO effect on development, since the other cells are still "flexible" in what they can become.
On the other hand, each cell division in insects, from the zygote on, is completely determinate, which means that decisions about what a cell will become are made with each division. The decisions that are made with the earliest cell divisions are as follows:
First division (of zygote) -- determines left and right sides
Second division -- determines front and back (at this point, there would be four cells, a front left, a front right, a back left and a back right)
Third division -- determines top from bottom (at this point, there would be eight cells, a front upper left, a front lower left, and so on)
Just to follow up on what I said about humans, if an insect cell were to be damaged after the third division, say the lower back right cell, you would end up with seven-eighths of an insect (missing the back lower right part of the abdomen, for instance) if development coul
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House insetcs of Peru
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