Regents Living Environment Test Preparation Practice

    Maintainance Of Homeostasis


    Base your answers to questions 2 on the diagrams below and on your knowledge of biology. The diagrams represent some of the systems that make up the human body.

    homeostasis and immunity, systems of human body fig: lenv12018-examw_g12.png


    Base your answers to questions 8 on the diagram below and on your knowledge of biology. This diagram represents the roles of different parts of the human body in keeping blood sugar at a balanced, normal level over time.

    organization and patterns in Life, interactions among structural componenets, homeostasis and immunity, maintainance of homeostasis, interaction and control mechanisms fig: lenv82016-exam_g10.png


    Base your answers to questions 14 on the passage below and on your knowledge of biology.

    The Protein Shredder

    In every cell, thousands of important processes are occurring around the clock. One of the ways a cell manages to coordinate all of these processes is by sending protein messages. After the protein messages are delivered and read, they need to be destroyed to prepare for the arrival of the next message.

    The task of destroying these proteins falls on cell structures known as proteasomes. Think of a proteasome as a tubelike protein shredder. Protein molecules that have served their purpose are transported to the proteasome, unfolded, fed through the tube, and cut into smaller molecules that can then be used to synthesize new protein molecules. Proteasomes can shred any type of protein.

    Individuals with a neurological disorder known as hereditary ataxia have been found to have an excess of protein in the cells of their brains and spinal cords. The abnormal level somehow leads to the death of cells in portions of the cerebellum. These areas of cell loss can be seen on a brain scan.

    There are several forms of hereditary ataxia but all of them result in poor coordination. The symptoms progress over a period of years. In the beginning, the individuals experience only minor coordination problems. As time passes, the symptoms become worse. The affected individuals will have poor balance when walking. They will be clumsy and have difficulty talking and swallowing.


    Base your answers to questions 15 on the information below and on your knowledge of biology.

    The fight-or-flight response in humans prepares the body to fight off or run away from a potential threat. This response results from a series of nerve and chemical signals that direct how cells function. This, in turn, determines the actions of organs in these situations.

    Some of the changes experienced by the individuals as part of this response include:

    increased pulse rate increased blood glucose levels increased breathing rate