Modern biotechnology is based on
(a) Protoplast fusion
(b) Tissue culture
(c) Recombinant proteins
(d) Genetic engineering

Options

A. Protoplast fusion
B. Tissue culture
C. Recombinant proteins
D. Genetic engineering

Answer

To solve the question "Modern biotechnology is based on," we will analyze each option provided:

1. **Protoplast fusion (Option A)**:
- Protoplast fusion is a technique used in plant biotechnology where the cell walls of two different plant cells are removed, allowing them to fuse and form a hybrid cell. While it is an important technique, it is not the foundational basis of modern biotechnology. Therefore, this option is incorrect.

2. **Tissue culture (Option B)**:
- Tissue culture refers to the growth of cells or tissues in an artificial medium. It is a significant technique in biotechnology, especially in plant propagation and genetic studies. However, like protoplast fusion, it is a method used within biotechnology rather than the foundational principle of modern biotechnology. Thus, this option is also incorrect.

3. **Recombinant proteins (Option C)**:
- Recombinant proteins are proteins that are genetically engineered by inserting a gene from one organism into another organism, allowing it to produce that protein. While recombinant proteins are a product of biotechnological processes, they do not represent the foundational principle of modern biotechnology. Therefore, this option is incorrect.

4. **Genetic engineering (Option D)**:
- Genetic engineering involves the direct manipulation of an organism's genes using biotechnology. It includes techniques like the insertion of foreign DNA into a host organism, leading to changes in the organism's phenotype. This method is indeed a cornerstone of modern biotechnology, as it allows for the development of genetically modified organisms (GMOs) and various biotechnological applications. Thus, this option is correct.

**Final Answer**: The correct answer is (d) Genetic engineering.

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