NAS 2 CHALLENGE TEST Exam Questions With Answers (Verified And Answers)

NAS 2 CHALLENGE TEST Exam Questions With Answers (Verified And Answers) Purpose of the scientific method - answeran organized way to solve a problem or answer a question independent variable - answera 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? - answer1. question 2. Hypothesis 3. experiment 4. observation 5. analyze 6. conclusion dependent variable - answera variable that depends on other factors or variables ex: how much the plant grows control group - answergroup that does not receive any treatment and is used to compare or measure the other subjects experimental group - answergroup that receives treatment in an experiment what are the six levels of organization - answerchemical, cellular, tissue, organ, organ system, organism identify the requirements of life - answerresponse to stimuli, reproduction, metabolism, cellular organization, regulation, growth and development, homeostasis identify survival needs - answeroxygen, nutrients, water, body temperature, atmospheric pressure define homeostasis - answerbody maintains a stable internal environment while adjusting to external conditions Receptor - answera sensor that monitors the environment and responds to changes (called stimuli) by sending the information to the control center control center - answerdetermines the set point (level or range a variable is to be maintained at), analyzes the information it receives, and determines the appropriate response. effector - answerprovides the means for the control center's response to the stimulus negative feedback mechanisms - answera 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 - answera 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 - answerpositive, in the nucleus electron - answernegatively charged particle in the outer shell neutron - answerneutral charge, in the nucleus number of protons is the same as? - answerthe number of electrons what is the atomic number equal to - answernumber of protons (atomic number is top left above atomic symbol) atomic mass - answerthe same as the protons and neutrons added together (at the bottom below atomic symbol) characteristics of ionic bonds - answerbetween 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 - answerbetween 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 - answermore 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 - answerelectrons are shared equally between two atoms polar covalent bond - answerunequal sharing of electrons between two atoms