Define.
A group of cells that work together to perform a similar function.
A. Tissue
B. Organ
C. Organelle
D. Molecule
A. Tissue
The correct answer is A. Tissue.
To arrive at this answer, we can break down the question and analyze the given options.
The question asks for the definition of a "group of cells that work together to perform a similar function."
Option A. Tissue: A tissue is a group of cells that work together to perform a similar function. It is a higher organizational level than individual cells but lower than an organ.
Option B. Organ: An organ is a more complex structure made up of different tissues working together to perform a specific function. It is a higher organizational level than tissue.
Option C. Organelle: An organelle is a specialized structure within a cell that performs specific functions. It is a smaller organizational level than tissue.
Option D. Molecule: A molecule is a group of atoms bonded together. It is not related to the definition of a group of cells working together to perform a similar function.
By comparing the definitions of the options, we can determine that the correct answer is A. Tissue, as it best matches the given definition.
The correct answer is A. Tissue.
Tissue refers to a group of cells that work together to perform a similar function.