The correct answer is: B. Cell
A cell is the smallest unit of life that is capable of carrying out all the functions necessary for life. Cells are the basic building blocks of all living things, from plants and animals to bacteria and archaea.
Cells are incredibly diverse, but they all share some common features. All cells have a cell membrane, which is a thin layer that surrounds the cell and protects it from the environment. All cells also have cytoplasm, which is a jelly-like substance that fills the cell. Cytoplasm contains many different organelles, which are specialized structures that carry out specific functions in the cell.
Cells come in two main types: prokaryotic cells and eukaryotic cells. Prokaryotic cells are the simplest type of cell. They do not have a nucleus or any other membrane-bound organelles. Eukaryotic cells are more complex than prokaryotic cells. They have a nucleus, which is a membrane-bound structure that contains the cell’s DNA. Eukaryotic cells also have other membrane-bound organelles, such as mitochondria, which produce energy for the cell.
Cells are the basic units of life, and they are responsible for all the functions that living things need to survive. Cells are constantly dividing and multiplying, and they can also change shape and function in response to their environment. This ability to change and adapt is what allows cells to survive and thrive in a variety of different environments.
Here is a brief explanation of each option:
- A. Tissue is a group of cells that are similar in structure and function. Tissues are the basic building blocks of organs.
- C. Blood is a fluid that circulates through the body and carries oxygen and nutrients to the cells. Blood also helps to remove waste products from the cells.
- D. DNA is a molecule that contains the genetic code for an organism. DNA is found in the nucleus of every cell.