Which of the following is a part of the cell theory?

a. all cells contain a nucleus
b. organs are the basic units of life
c. new cells arise spontaneously on their own
d. new cells are produced from existing cells

The correct option is D. New cells are produced from existing cells is a part of the cell theory.

Explanation:

Cell theory can be described as one of the earliest theories of biology which states that cells are the basic unit of life out of which all living things are made. The modern cell theory comprises of three main parts:

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.

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".