Here's why:

* Genetically modified (GM) crops are plants whose genetic material (DNA) has been altered in a way that doesn't occur naturally, using biotechnology. This modification can be done to introduce new traits, such as:

* Increased yield: This is often achieved by making the plant more resistant to pests, diseases, or harsh environmental conditions.

* Improved nutritional content: This can involve increasing the levels of certain vitamins or minerals in the crop.

* Herbicide tolerance: This allows farmers to use specific herbicides to control weeds without harming the crop.

* Bioengineered crops is another term for GM crops that emphasizes the use of biological techniques to modify the plant's DNA.

While GM crops often aim to increase yield, it's important to note that:

* Yield increase is not the only goal of GM crops. They can be engineered for many other reasons, such as improved nutritional value or resistance to disease.

* Not all GM crops necessarily have higher yields. Some may be designed for other beneficial traits.

In conclusion, the term "genetically modified (GM) crops" or "bioengineered crops" accurately describes the process of artificially changing a crop's heredity material.