The correct answer is B. Cell.
A cell is the basic structural and functional unit of all known living organisms. Cells are the smallest unit of life that can replicate independently, and are often called the “building blocks of life”.
Cells are typically organized into tissues, which are groups of similar cells that work together to perform a specific function. Tissues are then organized into organs, which are groups of tissues that work together to perform a more complex function. Organs are then organized into organ systems, which are groups of organs that work together to perform a specific function for the organism as a whole.
The basic structure of a cell is a membrane-bound sac that contains cytoplasm, which is a jelly-like substance that contains organelles. Organelles are specialized structures that perform specific functions within the cell. Some common organelles include the nucleus, which contains the cell’s DNA; the mitochondria, which produce energy for the cell; and the ribosomes, which produce proteins.
Cells come in a variety of shapes and sizes, but all cells share some common features. These features include a cell membrane, cytoplasm, and organelles. The cell membrane is a thin, flexible barrier that surrounds the cell and protects it from the environment. The cytoplasm is the jelly-like substance inside the cell membrane. It contains water, salts, proteins, and other molecules. The organelles are specialized structures that perform specific functions within the cell.
Cells are the basic units of life, and they are responsible for all of the functions that living organisms perform. Cells are able to reproduce, grow, and develop. They are also able to respond to their environment and adapt to changes. Cells are essential for life, and they are the building blocks of all living things.
The other options are incorrect because they are not the basic structural and functional unit of all organisms.
- A. Tissue is a group of similar cells that work together to perform a specific function.
- C. Gland is an organ that produces and releases a substance.
- D. Atom is the smallest unit of matter that retains all of the chemical properties of an element.