a vegetable is a kind of plant & an onion is a kind of vegetable ->  an onion is a kind of plant  a plant cell is box-like in shape & a plant is made of plant cells ->  a plant is made of box-like plant cells  an onion is a kind of plant & a plant is made of box-like plant cells ->  an onion is made of box-like onion cells  an onion is made of box-like onion cells & a lots of box-like objects are seen under a microscope on a slice of onion -> the objects seen under the microscope are onion cells