Rickets is a disease of childhood characterized by the softening of the bones from an inadequate intake of and insufficient exposure to sunlight.

advantage of using stem cells in medical research:

1.       it provides medical benefits in the fields of therapeutic cloning and regenerative medicine.

2. it provides great potential for discovering treatments and cures to a variety of diseases including parkinson disease, spinal cord injuries, diabetes, alzheimer’s disease and many more.

3. limbs and organ could be grown in lab from stem cells and then used in transplant or treat illness.

sex cells are usually half's then they find another half and make a fertilize egg

b a mature ovary of a plant.