Those plants whose genes have been altered by manipulation are known as ____.

Genetically modified plants

The correct answer is Option (2) → Genetically modified plants   

Plants, bacteria, fungi and animals whose genes have been altered by manipulation are called Genetically Modified Organisms (GMO) and plants whose genes have been altered by manipulation are called Genetically Modified Plants. GM plants have been useful in many ways. Genetic modification has:

(i) made crops more tolerant to abiotic stresses (cold, drought, salt, heat).

(ii) reduced reliance on chemical pesticides (pest-resistant crops).

(iii) helped to reduce post harvest losses.

(iv) increased efficiency of mineral usage by plants (this prevents early exhaustion of fertility of soil).

(v) enhanced nutritional value of food, e.g., golden rice, i.e., Vitamin ‘A’ enriched rice.

GM crops are often developed to increase yield by making them more resistant to pests, diseases, and abiotic stresses (such as drought, salinity, and extreme temperatures). Other benefits of GM crops include pest resistance and enhanced nutritional value, both of which contribute to better crop productivity and quality.