Final answer:
Unsaturated fat, mainly from plant sources, is liquid at room temperature and includes monounsaturated and polyunsaturated fats with one or more double bonds.
Step-by-step explanation:
The type of fat that is primarily sourced from plants and remains liquid at room temperature is referred to as unsaturated fat. Within this category, there are two types: monounsaturated fat and polyunsaturated fat. Monounsaturated fats contain one double bond in their molecules, examples being olive oil and canola oil, and tend to be liquid due to the kinks in the carbon chain caused by these double bonds, preventing the fat molecules from packing tightly together. In contrast, saturated fats, mainly sourced from animals, have no double bonds, meaning they can pack tightly and are typically solid at room temperature.
The fat that comes primarily from plant sources and is liquid at room temperature is called unsaturated fat. Most unsaturated fats are liquid at room temperature and are called oils. If there is one double bond in the molecule, then it is known as a monounsaturated fat (e.g., olive oil).