Bumblebees of the subgenus Psithyrus (known as 'cuckoo bumblebees', and formerly considered a separate genus) are brood parasites, sometimes called kleptoparasites, in the colonies of other bumblebees, and have lost the ability to collect pollen.ueen and worker bumblebees can sting. Unlike in honeybees, a bumblebee's stinger lacks barbs, so the bee can sting repeatedly without injuring itself; by the same token, the stinger is not left in the wound. Bumblebee species are not normally aggressive, but may sting in defence of their nest, or if harmed.
STEM CELLS SAVE LIVES. For decades, doctors have harnessed the unique ability of stem cells to treat leukemia and genetic blood diseases. But now, researchers are discovering that these cells have the power to heal, to fight disease, and to regenerate damaged or aging tissue throughout the body. To fully understand why they hold the potential to change your childâs medical future, get to know more about stem cells.
A stem cell is essentially the building block of the human body. Stem cells are capable of dividing for long periods of time, are unspecialized, but can develop into specialized cells. The earliest stem cells in the human body are those found in the human embryo.The stem cells inside an embryo will eventually give rise to every cell, tissue and organ in the fetus's body. Unlike a regular cell, which can only replicate to create more of its own kind of cell, a stem cell is pluripotent.When it divides, it can make any one of the 220 different cells in the human body. Stem cells also have the capability to self-renew -- they can reproduce themselves many times over.nlike a regular cell, which can only replicate to create more of its own kind of cell, a stem cell is pluripotent. When it divides, it can make any one of the 220 different cells in the human body. Stem cells also have the capability to self-renew -- they can reproduce themselves many times over.