Which of the following cells present in loose connective tissue are responsible for collagen fiber and complex carbohydrate production?

The cells in loose connective tissue that are responsible for the production of collagen fibers and complex carbohydrates are called fibroblasts.

Here are the steps to answer this question:

1. Understand the question: The question is asking about a specific type of cell found in loose connective tissue that has the function of producing collagen fibers and complex carbohydrates.

2. Identify the cell: The cell that fits this description is the fibroblast. Fibroblasts are the most common cells of connective tissue in animals.

3. Understand the function of the cell: Fibroblasts produce the structural framework (stroma) for many tissues, and play a critical role in wound healing. They are the main cells responsible for the production of collagen fibers and complex carbohydrates (glycosaminoglycans), which are both essential components of the extracellular matrix.

So, the answer to the question is fibroblasts.