NAS 2 CHALLENGE TEST Questions And Answers 100% Verified.

NAS 2 CHALLENGE TEST Questions And Answers 100% Verified. purpose of the scientific method - correct answer. an organized way to solve a problem or answer a question independent variable - correct answer. a variable that the researcher controls and is not affected by other variables ex: amount of water a plant receives What are the steps of the scientific method? - correct answer. 1. question 2. Hypothesis 3. experiment 4. observation 5. analyze 6. conclusion dependent variable - correct answer. a variable that depends on other factors or variables ex: how much the plant grows control group - correct answer. group that does not receive any treatment and is used to compare or measure the other subjects experimental group - correct answer. group that receives treatment in an experiment what are the six levels of organization - correct answer. chemical, cellular, tissue, organ, organ system, organism identify the requirements of life - correct answer. response to stimuli, reproduction, metabolism, cellular organization, regulation, growth and development, homeostasis identify survival needs - correct answer. oxygen, nutrients, water, body temperature, atmospheric pressure define homeostasis - correct answer. body maintains a stable internal environment while adjusting to external conditions Receptor - correct answer. a sensor that monitors the environment and responds to changes (called stimuli) by sending the information to the control center control center - correct answer. determines the set point (level or range a variable is to be maintained at), analyzes the information it receives, and determines the appropriate response. effector - correct answer. provides the means for the control center's response to the stimulus negative feedback mechanisms - correct answer. a feedback mechanism that slows or stops a process. Reduces the effect of the stimulus which decreases productivity ex: the control of blood sugar positive feedback mechanisms - correct answer. a feedback mechanism that results in the enhancement of the original stimulus so the activity is accelerated ex: childbirth (if childbirth takes too long the life of the mother and baby are at risk) protons - correct answer. positive, in the nucleus electron - correct answer. negatively charged particle in the outer shell neutron - correct answer. neutral charge, in the nucleus number of protons is the same as? - correct answer. the number of electrons what is the atomic number equal to - correct answer. number of protons (atomic number is top left above atomic symbol) atomic mass - correct answer. the same as the protons and neutrons added together (at the bottom below atomic symbol) characteristics of ionic bonds - correct answer. between metal and nonmetal, high melting and boiling points, generally solid at room temp, hard/brittle, conducts electricity, dissolves in water, gives up one or more electrons to another atom characteristics of covalent bonds - correct answer. between nonmetal only(metalloids), atoms share electrons, lower melting and boiling point, usually liquid and gas at room temp, soft, not a conductor of electricity, insoluble (don't dissolve) characteristics of hydrogen bonds - correct answer. more of an attraction than a bond, generally weak bond, always include hydrogen that is already part of a polar molecule ex: water non-polar covalent bond - correct answer. electrons are shared equally between two atoms polar covalent bond - correct answer. unequal sharing of electrons between two atoms substrate - correct answer. reactant acted upon by an enzyme active site - correct answer. part of an enzyme to which substrate binds and where a reaction is catalyzed enzymes - correct answer. -promotes chemical reactions by bringing substrates together in an optimal orientation, therefore creating an ideal chemical environment for the reaction to occur -catalyzes chemical reactions by lowering activation energy barriers an converting substrate molecules to products decomposition reaction - correct answer. bonds between components of a larger molecule are broken ex: bookworm --- book+worm synthesis reaction - correct answer. two components bond to make a larger molecule ex: note+book --- notebook exchange reaction - correct answer. bonds are both formed and broken such that the components of the reactants are rearranged ex:notebook+worm --- note+bookworm describe how enzyme catalyze chemical reactions - correct answer. enzymes decrease the activation energy required for a given chemical reaction to occur. helps speed up the rate of reaction identify waters role in life - correct answer. water is the universal solvent, helps cells transport and use substances like oxygen or nutrients, helps regulate body temp, hydration and moisturizes the body, lubrication for joints define ph - correct answer. measure of acidity or basicity identify values for acid on ph scale - correct answer. ph below 7 is acidic identify values for alkaline on ph scale - correct answer. ph above 7 is basic/alkaline