Question 2

The basic unit of life and the building block of tissues and organs is the cell.

Cells are the fundamental units of life, serving as the basic building blocks for all living organisms. They are essential for the structure and function of tissues and organs, making them central to biological processes.

A) Atom

Atoms are the smallest units of matter and form the basis for all chemical elements. While they are foundational to the structure of matter, they do not possess the characteristics necessary to be considered living units or building blocks of tissues and organs.

B) Organelle

Organelles are specialized structures within a cell that perform distinct processes, such as energy production or protein synthesis. Although they are vital for the functionality of cells, they are not independent units of life or the primary building blocks of tissues and organs.

C) Cell

Cells are indeed the basic unit of life and serve as the building blocks of tissues and organs. They are capable of carrying out all life processes, including metabolism, growth, and reproduction, which makes them essential in the formation of more complex structures in living organisms.

D) DNA

DNA is the hereditary material in living organisms and carries the genetic information necessary for the development and functioning of cells. While it is crucial for cellular processes and inheritance, it is not a unit of life or a building block of tissues and organs in itself.

Conclusion

The cell is the correct answer as it is the fundamental unit of life that composes all tissues and organs. All other options—atom, organelle, and DNA—are important in their own right but do not fulfill the definition of a basic unit of life or serve as building blocks in the context of biological organization.