Game guide:Getting a Forbidden fruit

A forbidden fruit is a type of produce introduced in The Sims 3: University Life. If your Sim is to eat it they will turn into a PlantSim, the new occult introduced in University Life.

Getting the Seed
Your Sim will need to have a Science Research Station and a seed, which can easily be acquired by taking a Gardening class or just collecting one from the ground. Click on your Science Research Station and select "Gene Splicing Experiment..." You may want to have multiple seeds in your inventory, as the experiment can fail many times. Once you have succeeded in performing the experiment, you will need a level 7 Gardening skill to plant it.

Method 1: Planting
To plant the seed, your Sim will need a level 7 gardening skill, which can easily be reached by using the Brain Enhancing Machine. Once the skill level is reached, you can plant it anywhere on your home lot. Take care of it, and 5 days later it will be fully grown. Sometimes, the plant will die quickly after it is ready for harvest, so harvest it quickly. There is a 50% chance you will get a PlantSim baby and a 50% chance you will get a Forbidden Fruit. If you get the Forbidden Fruit, you can eat it, and 4 hours later your Sim will turn into a PlantSim.

Method 2: Cloning
To clone the seed, your Sim will need a level 9 Science skill. Unfortunately, you can not use the Brain Enhancement Machine to advance in this skill. Once the level is reached, you will need to get a sample from the Forbidden Fruit seed. Once you get the sample, select it from your inventory and click "Clone from Sample." There is a chance it will come out as a Forbidden Fruit.

Method 3: Using Cheats.
By using the debug mode, one can visit the debug catalog in which many readymade plants with their produce are available. Select the forbidden planet and you can have the fruit.