Marissa is in 10th grade. She comes from a family of mechanics. Her dad and three brothers are mechanics, and her grandfather owns a garage. Marissa has secretly wanted to work on cars but has been afraid to tell her family. She now wants to approach her grandfather for a summer job. Why do you think Marissa has kept her career dream a secret? How might she ask her grandfather for a summer job?

Biologists recognize five levels of cell organization. the lowest and simplest is the cellular level. organisms here are either unicellular organisms, like protozoa, or colonial organisms. colonial organisms are composed of single-celled individuals that stay together to sustain the life of the whole colony. next on the scale of complexity is the level occupied by tissue. a tissue is a group of similar cells which perform a similar activity. tissues that are organized around a common function together make up an organ, the third level of complexity. the fourth level of organization is the system, formed by a group of organs which together perform a specific bodily process. the fifth and highest level is the organism level, in which body systems work together in a structure capable of independent life. main idea: