Intro to Biology (college) Exam 1 Questions with Correct Answers

What are the characteristics common to all living things? - ANSWERS• All living things are made of cells • All living things are organized and made of the same molecules • All living things grow, develop, and reproduce • All living things use raw materials, produce, and use energy • All living things respond to the environment • All living things maintain homeostasis • Populations of living things evolve what determines if something is a science? - ANSWERS• Focuses on the natural world • Aims to explain the natural world • Uses testable ideas • Relies on evidence • Usually leads to ongoing research • Involves the scientific community What does science do? - ANSWERSit aims to understand the natural world through observation and reasoning What are two major types of reasoning used in science? - ANSWERS• deductive reasoning- from general to specific • inductive reasoning- from specific to general What are the main steps of the scientific method? - ANSWERS- Observation - Hypothesis - Prediction - Experimentation - Conclusion hypothesis - ANSWERSpossible explanation for an observation prediction - ANSWERSwhat you expect if your hypothesis were true peer review - ANSWERSpeople who read an article and provide feedback basic research - ANSWERSis intended to extend the boundaries of what we know applied research - ANSWERS- Foundation provided by basic research - May involve the manufacture of food additives or drugs Hypothesis vs. Theory - ANSWERS• Hypotheses - proposed explanations for a narrow set of phenomena • Theories - broad explanations for a wide range of phenomena. Theories integrate and generate many hypotheses. What are some types of evidence that support the Theory of Evolution through Natural Selection? - ANSWERS How did the atmosphere of early earth differ from now? - ANSWERSPopular view of early atmosphere: • Carbon dioxide • Nitrogen gas • Water vapor • Hydrogen gas • Other sulfur, nitrogen, and carbon compound Current atmosphere: • Nitrogen •Oxygen • Argon • Carbon dioxide • Other trace molecules. What did Miller-Urey experiment demonstrate? - ANSWERSreproduce early atmosphere Where are some current hypotheses for the source of the first biological molecules? - ANSWERS what are microspheres and why are they important in understanding the origin of life? - ANSWERSthey are pre-cells. What was the first probable genetic material? - ANSWERSRNA What are the first fossil signs of life on earth? - ANSWERS• 3.7 BYA by stromatolites (BY= billion years) • 3.0-3.1 BY fossil cells • 1.3-1.8 BY First complex cells (with organelles) • 700 MY Multicellularity What are stromatolites? - ANSWERSstructures produced by microorganisms by trapping of sediments and other particles What is matter? - ANSWERSAnything that has mass and occupies space What are elements? - ANSWERSbasic building blocks of matter that cannot be broken down by chemical means. What is an atom and what is its structure? - ANSWERSthe smallest unit of an element that still has all the properties of that element. consists of 3 types of subatomical particles (protons, neutrons, electrons) What is the atomic number - ANSWERS# of protons atomic mass - ANSWERS# of protons and neutrons What are isotopes and how do they differ from each other? - ANSWERSAtoms of same element with different number of neutrons. What is the octect rule? - ANSWERS• The inner shell holds only 2 e- • The outer shell of each atom can hold 8 e- • Atoms are more stable if they fill their outer shell • Unpaired e- make an element reactive What makes an atom stable or reactive? - ANSWERSAtoms are more stable if they fill their outer shell Unpaired e- make an element reactive What are ions, cations and anions? - ANSWERSion- Atoms may lose or gain electrons Cations - are positively charged ions Anions - are negatively charged ions What is oxidation, reduction, and how to these names relate to electron giving and receiving? - ANSWERSoxidation- losing electrons (give) reduction- gaining electrons (receive)