BIO 189 Exam 1 | Answered with complete solutions

BIO 189 Exam 1 | Answered with complete solutions Summarize the five characteristics of life 1. Organization: atoms make up molecules, which make up cells, which make up tissues, and so on. 2. energy use: a kitten uses the energy from its mothers milk to fuel its own growth 3. maintenance of internal consistency (homeostasis): your kidneys regulate your body's water balance by adjusting the concentration of your urine 4. Reproduction, growth, and development: an acorn germinates, developed into an oak seedling, and, at maturity, reproduces sexually to produce its own acorns 5. Evolution: increasing numbers of bacteria survive treatment with antibiotic drugs. All of the following are characteristics of life EXCEPT: a. evolution b. reproduction c. homeostasis d. multicellularity The concentration of salts in blood remains relatively steady, regardless of a person's diet. This situation best illustrates: a. homeostasis b. life organizational hierarchy c. autotrophy d. evolution Illustrate life's organizational hierarchy - atom - molecule - organelle - cell - tissue - organ - organ system - organism - population - community - ecosystem - biosphere atom smallest chemical unit of a pure substance molecule A group of atoms bonded together organelle a membrane bound structure that has a specific function within a cell cell fundamental unit of life, multicellular or unicellular tissue collection of specialized cells that function in a coordinated fashion organ structure consisting of tissues organized to interact and carry out specific functions organ system organs connected physically or chemically that function together organism An individual living thing Population a group of the same species of organisms living in the same place and time community all populations that occupy the same region ecosystem living and nonliving things in an area biosphere the global ecosystem, the parts of the planet and its atmosphere where life is possible Which of the following is smaller than an organelle? a. an organ b. a molecule c. a cell d. a tissue Autotroph vs Heterotroph Autotrophs are organisms that can produce their own food from the substances available in their surroundings using light (photosynthesis) or chemical energy (chemosynthesis). Heterotrophs cannot synthesize their own food and rely on other organisms — both plants and animals — for nutrition. Because plants extract nutrients from soil and use sunlight as an energy source they are considered to be Autotrophs Decomposers Organisms that break down the dead remains of other organisms Evolution through natural selection will occur most rapidly for populations of plants that - Domain bacteria - prokaryotic - not a membrane bound organelle - genome is located in the nucleoid - they are generally smaller - they are unicellular (single-celled) Domain archaea - prokaryotic - not a membrane bound organelle - genome is located in the nucleoid - they are generally smaller - they are unicellular (single-celled) Domain eukarya - Eukaryotic - they are a membrane bound organelle - genome is located in the nucleus (membrane bound organelle) - they are generally larger - they are often multicellular but they can be unicellular Taxonomic Hierarchy Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species (most inclusive to least inclusive) How do we write out humans scientific name? - in italics Homo sapiens What is an example of each domain of life? - Characteristics associated with the process of science - multiple experiments - reproducibility - uncertainty scientific method a general way of using evidence to answer questions and test ideas. a continuous circle: hypothesis-design-experiment-data-conclusions, and all over again Steps of the Scientific Method Ask a Question Do Background Research Construct a Hypothesis Test Your Hypothesis by Doing an Experiment Analyze Your Data and Draw a Conclusion Communicate Your Results A scientist has just observed a new phenomenon and wonders how it happens. What is the next step in his or her discovery of the answer? a. Observe b. Hypothesize c. Experiment d. Peer review Factors to consider in experimental design - sample size - variables - controls - statistical analysis Sample size: the number of individuals in a sample independent variable the thing that will be changed in each experiment dependent variable The outcome factor; the variable that may change in response to manipulations of the independent variable. standardized variable any factor held constant for all subjects in an experiment Control untreated group used as a basis for comparison with a treated group in an experiment in an experiment to test the effect of temperature on the rate of bacterial reproduction, temperature would be the... indépendant variable Placebo an inert substance that resembles the treatment given to the experimental group Epidemiological studies advantages: comparatively inexpensive potential to study harmful factors statistical power: - sample number one time Theory an explanation of a natural phenomenon supported by many observations and experiments over time Can a theory be proven wrong? Yes, a new observation or interpretation of data could disprove a theory. Hypothesis a tentative explanation for one or more observations limitations to science inquiry - evidence may lead to multiple interpretation - experiments can fail to give a definitive answer - researchers may interpret observations or results - scientific community may be slow to accept new evidence that suggests unexpected conclusions Filing drawer syndrome failure to share negative results data image manipulation scientists editing photos releasing fake results Which of the following statements is false? a. emergent properties are function that arise from the interaction between an organisms parts. b. two of the three domains contain prokaryotic organisms c. when medical researchers test the effectiveness of a new drug, they typically compare the new drug to a placebo d. for a scientific study to be considered valid, the researchers must conduct experiments Asexual reproduction vs sexual reproduction Asexual reproduction generates offspring that are genetically identical to a single parent. In sexual reproduction, two parents contribute genetic information to produce unique offspring. Why is the cell considered the basic unit of life? because every organism consists of one or more cells Emergent properties new functions that arise from interactions among a system's components give an example of emergent properties from everyday life. brain cell - interacting brain cells - brain - memory Why is chemistry important to understand biology? It allows us to understand nutrition, allows us to test for drugs, sugars, hormones, and indicate pregnancy. General structure of atoms - electrons: rotating around the nucleus, negative charge -protons: in the nucleus, positive charge - neutrons: in the nucleus, natural charge Elements that make up most of the mass of all living organisms - Nitrogen - carbon - hydrogen - oxygen - phosphorus - sulfur How is the periodic table related to atomic structure elements are arranged by atomic number (number of protons) ion atom that has gained or lost electrons cation lost an electron (Na+) anion gain an electron, F- isotope atoms of the same element that have the same atomic number but different atomic masses atomic number the number of protons in the nucleus of an atom atomic mass calculated by adding the number of protons and neutrons a neutral hydrogen atom with a mass number of 1 has ___ neutrons, ___ protons, and ___ electrons 0; 1; 1 how many neutrons foes carbon -14 have in its nucleus? 8 atomic weight the average atomic mass of all atoms of an element chemical reaction interactions between atoms in which electrons are involved nuclear reaction A reaction that involves a change in the nucleus of an atom isotopes are unstable ionic bond - one atom donated - a more electronegative atom steals the other atoms electron, no sharing - an electrical attraction occurs between two atoms of different charter covalent bond - polar -non polar a pair of valence electrons is shared between two atoms forms during dehydration synthesis - polar: unequal sharing - non polar: equal hydrogen bond weak attraction between a partially negative and a partially positive atom is distinct from ionic and covalent because it is weak dehydration synthesis enzymes remove a hydroxyl group from one molecule and a hydrogen atom from another forming H2O and a new covalent bond between the two smaller components Hydrolysis breaks the covalent bond that links monomers enzymes use atoms from water to add a hydroxyl group to one molecule and hydrogen atom to another Electronegativity measures the atoms ability to attract electrons on a scale 0-4 How does electronegativity relate to the formation of ionic and covalent bonds electronegativity expresses how badly an atom wants or attracts EXTRA electrons, therefor forming bonds Relationship between the arrangement of the periodic table and electronegativity elements are arranged according to their valence electrons (columns) and their number of shells (rows) decreases as we move from top to bottom increases as we move from left to right single bond when each atoms shares one electron double bond when two atoms share two electrons each what can influence molecular polarity shape cohesion and adhesion cohesion: the tendency of water molecules to stick together adhesion: tendency to form hydrogen bonds with substances other that water (water in paper towel) three states of water - solid - liquid - gas hydrophilic vs hydrophobic substances hydrophilic: interact/dissolve with water hydrophobic: do not interact with water process of a solute dissolving in a solvent to form a solution water is a solvent: a chemical in which other substances called solutes, dissolve. A solution consists of one or most solutes dissolved in a liquid solvent How do acids and bases affect a solutions pH pH denotes how acidic or basic a solution is