The correct answer is: B. All living cells arise from pre-existing cells.
The cell theory is a scientific theory that includes three main components:
- All living things are made up of cells.
- Cells are the basic unit of life.
- New cells are produced from existing cells.
Option A is incorrect because DNA is not the only basis of genetic transfer. RNA is also involved in genetic transfer.
Option C is incorrect because not all cells are composed of the same organelles. For example, plant cells have chloroplasts, while animal cells do not.
Option D is incorrect because tissues are not formed from combinations of cells. Tissues are formed from groups of cells that work together to perform a specific function.
The cell theory is a fundamental concept in biology. It provides a framework for understanding the structure and function of living things. It also helps us to understand how diseases can spread and how they can be treated.