I am taking a midterm for Env. Science an i need help BIG TIME! 1. Why is absolute dating more accurate than relative dating?
2. The Pangaea theory supports the theory of plate tectonics because .
3. Why is a rain drop a particularly damaging element to soil?
4. On a global basis, which of the following is the largest reservoir of carbon?
I'll give 21 points an mark brainliest

midterm in test?

Explanation:

Evolution Review Sheet Answer Key4.5.20171.Relative dating is using comparison to date rocks or fossils.  Law of superposition and index fossils are both examples of relative dating.  Relative dating provides an estimate of age versus absolute dating that gives an exact age based on radioactive decay of Carbon-14 or Uranium-235.  Absolute dating is the most exact method for determining age of geologic samples.2.Trilobites and ammonites are both index fossils because they both lived on multiple continents and existed for a short amount of time.3.A half-life is the amount of time it takes for one-half of a radioactive isotope to decay or break down.Carbon-14, Uranium-235, Plutonium-2384.The question asks how much of a 96 g sample will be left after 8.1 days when the half-life is 2.7 days.  3 half-lives of gold go by in 8.1 days.  # of Half-livesTimeAmount00-2.696g12.748g25.424g38.112g5.The theory of continental drift is Alfred Wegener’s theory that the Earth is made of plates that move, or “drift” over time.  The theory suggests the continents were all once together as Pangea.  The puzzle-like fit of continents, fossils of plants and animals found at the boundaries of continents that are now apart,and the magnetic reversals on the sea-floor at points of sea-floor spreading are allevidence for continental drift.6.An ice core is a cylinder of ice drilled from the Antarctic or Greenland ice sheets.  Ice cores have dissolved gases trapped inside.  Scientists are able to study the gases in the ice cores to understand past climate(weather)conditions.7.Genetic variation naturally occurs as genes combine or mutate, there is variationamong organisms.  When variation or mutation gives an organism an advantage for survival, then that organism is more “fit”for its environment.  When an environment changes and the more fit organisms survive, thatis survival of the fittest.8.Homologous structures are when organisms have anatomical features that have the same structure even though they may have a different function.  The wings of a bat, legs of a cat, and human arms are all examples.Homologous structures indicate common ancestry.9.Genetic variation is when there is naturally occurring variation in a population due to the way genes combine (dominant and recessive) or mutations.  Examples of variation are:eye color, hair color, freckles, face shape, stripes, dimples10.The law of superposition says that youngest rocks or fossils are found in the top rock layers, oldest at the bottom.11.A, B, and C are all rock layers.  D is a fault.  E is an intrusion.

Evolution Review Sheet Answer Key4.5.2017B, A, C, E, D12.An analogousstructure is when organisms have features that serve the same purpose but their structure or the way they are built is different.Bird and butterfly wings; fins and flippers on fish or whales13.Time PeriodBioticAbioticPre-CambrianFirst signs of bacteria/lifePangea/supercontinent was all oneBeginning of EarthPaleozoicAge of Invertebrates(lots o’fish!)Trilobites & ammonitesEarth largely aquatic habitatMesozoicDinosaurs Roar!Extinction believed to be due to asteroid impact that blocked sunlight.PangeasplitsCenozoic EraMammals appeared!  Age of Mammals!Ice AgeCurrent time!14.There are THREE types of plate boundaries:  divergent is where sea-floor spreading occurs, convergent forms mountains and mountain ranges, transform faults cause earthquakes.15.ExampleType of DatingDescriptionCarbon-14AbsoluteUsed for dating living thingsIce coresRelativeTells of past climate and atmosphereIndex fossilsRelativeUsed for relative dating.  Trilobites and long half-life; used to date older materialsRock layersRelativeYoungeston the top; oldest

Explanation:

a physical change is being made.

the african cheetah.

this species has a relatively low level of genetic

variation because the population was reduced to a small size approxi-

mately 10,000 to 12,000 years ago.

chapter   outline

24.1

genes in populations and the hardy-

weinberg equation

24.2

factors that change allele and genotype

frequencies in populations

24.3     sources of new genetic variation

population   genetics

24

until   now,   we   have   primarily   focused   our   attention   on   genes  

within   individuals   and   their   related   family   members.   in   this  

chapter   and   chapters   25   and   26   ,   we   turn   to   the   study   of   genes   in  

a   population   or   species.   the   field   of

population   genetics

  is   con-

cerned   with   changes   in   genetic   variation   within   a   group   of   indi-

viduals   over   time.   population   geneticists   want   to   know   the   extent  

of   genetic   variation   within   populations,   why   it   exists,   and   how   it  

changes   over   the   course   of   many   generations.   the   field   of   popu-

lation   genetics   emerged   as   a   branch   of   genetics   in   the   1920s   and  

1930s.   its   mathematical   foundations   were   developed   by   theoreti-

cians   who   extended   the   principles   of   gregor   mendel   and   charles  

darwin   by   deriving   formulas   to   explain   the   occurrence   of   geno-

types   within   populations.   these   foundations   can   be   largely   attrib-

uted to three scientists: sir ronald fisher, sewall wright, and j. b. s.

haldane.   as   we   will   see,   support   for   their   mathematical   theories  

was provided by several researchers who analyzed the genetic com-

position   of   natural   and   experimental   populations.   more   recently,  

population   geneticists   have   used   techniques   to   probe   genetic  

variation   at   the   molecular   level.   in   addition,   staggering   advances  

in   computer   technology   have   aided   population   geneticists   in   the  

analysis   of   their   genetic   theories   and   data.   in   this   chapter,   we   will  

explore   the   genetic   variation   that   occurs   in   populations   and   con-

sider   the   reasons   why   the   genetic   composition   of   populations   may  

change over the course of several generations