<u>Answer:</u>
Discovery of vaccine for smallpox, viruses and actual organisms that cause many diseases lead to the development of Germ Theory.
<u>Explanation:</u>
- Theory was the 'predominant theory' of 'disease transmission' before germ theory but it is no longer accepted as a 'scientific theory' of diseases.
- 'Formal and reliable experiments' on germs and diseases relationship were 'conducted by Louis Pasteur'.
- He showed that growth of microorganisms was not a spontaneous generation and his pasteurization experiment provided key pieces of evidence that supported germ theory.
The correct answer is: Induction, because this could be easily changed by changing the cell's environment.
Cell differentiation (process by which cell becomes specialized) can be under the influence of many factors:
• Cytoplasmic influence because cytoplasm can influence and control the behaviour of nuclear genes.
• Embryonic induction-changing the cell environment
For example: if cells from one region of the embryo are transplanted to some other region that transplant will most likely differentiate according to the chemical regulators of the surrounding cells.
• Proteins present in a cell influences its differentiation
• Cell-Cell interactions via cell-cell adhesion and signalling molecules.
Fossils are physical evidence of preexisting organisms, either plant or animal. ... Fossils of any kind are useful in "reading the rock record," meaning they help us decipher the history of the earth. They can help us determine the geologic age and environment (the paleoenvironment) in which they were deposited.
