Which of the following best describes how genetic engineering can be used to improve crop production?

• A. By cross-pollinating unrelated plant species without any genetic modification.
• B. By increasing the number of chromosomes in crop plants to enhance their growth rate.
• C. By introducing genes that confer resistance to pests or diseases, reducing the need for chemical pesticides.
• D. By exposing seeds to high levels of radiation to induce random mutations.

Answer: (C)

Verified step by step guidance

1. Understand the concept of genetic engineering: it involves directly modifying the genetic material of an organism, often by introducing specific genes from other species to achieve desired traits.
2. Evaluate each option in the context of genetic engineering: cross-pollination is a traditional breeding method and does not involve direct genetic modification.
3. Recognize that increasing chromosome number (polyploidy) is a breeding technique but not typically classified as genetic engineering since it doesn't involve gene insertion or modification at the molecular level.
4. Identify that introducing genes conferring resistance to pests or diseases is a classic example of genetic engineering, as it involves inserting specific genes to improve crop traits and reduce pesticide use.
5. Note that exposing seeds to radiation causes random mutations, which is a form of mutagenesis, not precise genetic engineering.