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Quick study academic biology 1 600dpi

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Basic Concepts
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Biological Science: The Study of Life
Cell Theory:
Eukaryotic Cells:
Z
A. The Scientific Method: How scientists study biology
I. Observe phenomena and formulate testable and
fal s ifiable (in case they are wrong) hypotheses
2. Test hypotheses, collect data, and analyze statisti­
cally (if necessary)
B. What is life')
1. Characteristics: Metabolism, reproduction, growth,
movement, responsiveness, complex organization


All living things are composed of cell s and come from
cells
A. Cell Size: Small to maximi ze surface area to volume
ratio for regulating internal cell environment
B. Cell (Plasma) Membrane: Composed of fluid-like phos­
pholipid bilayer, proteins, cholesterol and glycoproteins
Cell (Plasma) Membrane

Evolution
Concept that all organisms are rel ated to each other by
common ancestry: The unifying theme in biology
A. Natural Selection: A mechani sm for thc occurrence
of evoluti on
I. Survival of those offspring best adapted to the
condition s in whieh they live:
3. Individuals produce sexually many morc ofl~
spring than could poss ibly survive
b. These otfspring are not identical (in most situa­
tions), but show variations based on genetic dit:
ferences
c. Essentially, those individuals with variations
that allow them to survive (i.e., adaptations) to
the age of reproduction can pass their genes on
to the next generation
d. Thus, nature is selecting oflspring and shaping
the evolution of species
2. Charles Darwin and Alfred Wallace, 19th century biol­
ogists, (onnulated the concept of natural selection
Organismal Evolution
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PLANTAE

FU GI


" ,! "tt.

Phosopholipid
bilaye r


Cholesterol

Channel
protein

Complex cellular organi zation
A. Membrane: Bound organelks induding the following: ....
I. Nucleus: DNA/chromosomes, control ce llular acti v- ,..
ities via genes
2. Nucleolus: Located within nucleu s. sit e I,) r ribo­
some synthesis
3. Rough endoplasmic reticulum: With ribosomes,
invo lved in protein synthes is
4. Smooth endoplasmic reticulum: With o ut ribo­
somes, involved primarily in lipid synthes is
5. Golgi apparatus: Packaging center for molecules:
carbohydrate synthesis
6. Lysosome: Contain s hydrol ytic e nzymes 1,,,· intra­
cellular digestion
7. Peroxisome: Invol ved in hydrogen peroxide synthe­
s is and uegradati o n
8. Chloroplast: Site of phot osynthesi s
9. Chromoplast: Non-green pigment s
10. Leukoplast: Stores stardl
II. Mitochondrion: ATP production
12. Vacuole: G eneral storage and space-fillin g
structure

Animal Cell


C. Cell Wall: Outside of cell membrane in some organisms:
composed of carbohydrate (c. g., cellulose or chitin) or

Mi cro fil Jmenl 1\

carbohydrate derivative (c.g., peptidoglycan)
D. Cytoplasm: Material outside nucleus
I. Sitc for mctabolic activity
2. Cytosol: Solutions with di ssolved substances slIch
as' glucose, CO" 0 2' etc.
3. Organelles: Membrane-bound subunits of cells
with specialized functions
E. Cytoskeleton: Supportive and metabolic structurc
composed of microtubu1es, microfilaments, and inter­
mediate filaments
Cytoskeleton

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mot>lh
endoplasmic

Riho, oml!"

ret iculum

Plant Cell
Pl a!-lma

mcmhrnne


Prokaryotic Cells:
Simpler cellular organi zation with no nucleus or other
membrane-bound organelles
B. Artificial Selection: Human selects traits in otf­
spring (ex: pets, farm crops)


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Flage llum

Domesticated Animals


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Goigi


apparatus



Energy and Life

Cell Reproduction

Cell Transport

Ou r Sun

Passive Transport

Cells reproduce in two steps:

O rganisms must use the sun's energy (d irectl y o r indi­
rectly) to become and rema in in an organ ized state
A. Meta bolism: SC:'ies of chemica l reacti ons involved in
storing (anabo lism) or re leasing (catabolism ) cnergy
B. Enzymes: Biologica l cata lyst: fac ilitate metabolic
chem ical reactions by speeding up rates and lowering
hea t req uirements
En zyml' Kinetics

A. Relies o n thermal energy of matter; the cell docs not
do wo rk: th ere arc fo ur categori es :
I. Diffusion: Movement from an area of high to low
conce ntrati o n
2. Facilitated diffusion : A permease, or mcmbrane
enzyme, carri es sub stan ce
3. Osmosis: Diffu sion across a se mi-pe rm eabl e
membrane
4. Bulk flow: Mass movements of fluid s a tTected by
pressure and solutes

Osmosis


A. M itosis: Di vision of nuclea r materia l
B. Cytokin esis: Division of re maining ce llular contents
of th e cytop lasm

Enzyme + Substrate Enzy me/S ubstrate Enzyme + Prod uct
complex
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E+ S

ElS com plex

E+ P

C. Ad enos ine t ri p hospha te (AT P): A hi g h-energy
mol ec ul e; energy stored in ATP is rel eased by break­
ing phosph atc-to- pho sph ate bonds and creat ing
ad enos in e d iphos phate ( AD P) o r adenos ine
ll1o no phosphak (AM P) ; AT P is recycled by adding
bac k ph osphate g roups us ing energy [i'om th e sun
E nergy and ATP

applied

to pistlJn to rL's ist
upward movement

Wa ter plus solute

Cell Cycle
A. Cells go th ro ugh 4 slag s:
I. G, : Acti ve growth and metabo lis m
2. S : D NA synthes is ancl du pl ication
3. G , : Sy lllilcs is o f mo lecules in pre paration for
cell div isio n
a. Stages G, . S, & G, above arc collec ti\ d)
referred to as In terpha se: Interphase chrnmo­
so mes nrc re ferred to as chromatin , a dilrw;e.
loosely sca ttered arrange ment o f chro moso me,
4. M itosis & C ytoki nesis:
a. Mit otic chrom osomes in the M it os i ~;lCy t o k i ­
nesis stage are hig hly co ndensed and coikd.
and thu s di sti nct
Cell Cycle

Mo lecule of so lute

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ATP

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Ne t mo vement or watcr 1ll011:culcs

Active Transport

Mitosis - Four Mit otic Stages:

A. Relies on the cell provid in g energy supply; there arc
three catego ri es:
I. Membrane pumps: Permease L1sed to move s ub­
stance, usually in the opposite di rection of diffusio n
M emb rane P u mp - ATP Required

A. Prophasl': Chromosomes co ndense a nd organ­
ize ; nuc lea r membrane and nuclcoli d isappear:
sp indle apparat us assembled and attached [ 0 ccn­
tromeres of dup li cated chromosomes
B. Metaphase: Spind les line up duplicated ch romo­
so mcs alo ng eq uator o f cell, o ne spindl e to each half
or ch romatid o f du plica ted chro mosome
C. AnaphaS(': Centromere of each duplicated chromosome
is separated and pa ired chromatids arc pulkd apart
D. Telop hase : Chromosomcs uncuil : nucleoli reappear:
cyto kin sis occu rs and two genetically identical
daug htcr cells arc prod uced
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tNTLRI'H SE
PllllSO ph olipici

Photosynthesis
Sunligh t or radiant cnergy is captured by chl orophyll
and carotenoid photopi gll1en ts (found in cytopl asm in
prokaryotcs and chlorop lasts in eukaryotes ) in two
main stcps:
A. Light-depen den t reactio ns ( Light Reactions): The
ca ptu red light energy is transferred to electrons that
come from 11,0 : 0 , is a by-product
B. Light-independent reactions (Dark Reactions):
L:ncrgized electrons m'c u"1I1sferred to CO, (reduction
reactions) to form glucose (in the Calvin-Benson cycle)

Cell Resp iration
lI ighly energ ized electrons stored temporarily in g lu­
cose arc removed (oxidation react ions ) in a step-wi se
fa shion to maximi ze energy capture at each step:
A. Glycolysis: Anae robic process in cytopla sm in whic h
glucose, a six-carbon compound, is oxidized to two
pyruvtltcs, which arc both three-carbo n cha ins
B. K rebs cycle: Aerobic process that ox id izes py ru vates
to CO,
C. Che miosmotic phosphory latio n: T he ene rg ized
el ectrons released durin g the previous steps arc used
to concen trate hydrogen ions in one area (of the ce ll
membra ne in prokaryotes; of the m itoc hondrion in
cuka ryotes ) to create a chemica l g radi ent betwee n
positively and negatively charged ions (i. e., a bat­
tery ); the potential energy resu lting from this osmot­
ic gradient is used to resynthesize AT P from ADP
and A MP; after e lectrons havc been used, they must
be trans ferred to 0 ,

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bilayer

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,Nuclea r

PROPltASE

MEIAPII . \~[

(\mdcns ing

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Cho lesterol

2. Endocytosis: Ma teria ls arc bro ught in to cell via:
i. Phagocytosis: So lids
ii. Pinocytosis: Liquids
P hagocytosis
Pinocytosis
"Cell eating"
"Cell drin k ing"

p" irs

Nucleolus

ANAP II AS I

'pi ndle lomlation

ptndlc pole

TELOP II ASE

Chromosomes
dccondcn:-.. ing

3. Exocytosis: Ex pe l materia ls fro m ce ll
Exocytosis
INTERPIIASF of" Daughter Cells

Secretory

vesicle


Two new cells mc genetically identical (i .c ..
2

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-

[vir.

Organismal Reproductio n and
Meiosis
Sexual Processes
A. Sexual Reproduction: Involves the fusion of genet­
ic material (gametes) from two parental organisms
B. To ensure the proper chrolllosomal numbers in
the zygote (fertilized egg ), each gamete Illust
have half or haploid (N) of the original diploid
(2N) amount of DNA
C. Meiosis: Reduces thc chromosome number by
half and resuits in new geneti c combinations in
the gametes
Meiosis - 2 distinct stages
Preceded by Interphase; many meiotic events similar
to mitosis; ditTerences arc noted below
A. Meiosi s I

(j~
P,lIl cd hOl11oIO\!ou:-;

chro mosolllC's '-'
Prophase

Mclaplwsc

Anaphase I

Telophase I

1.

Genetics .. Mendel
Introduction
A. Genetics: The stud y of traits and their inh eritance
13. 19th century biol ogi sts believed that trait s blended; if
blending occurrecl things would become more simi­
lar, not differcnt; Darwin and Wallace stated th at
variation s or differences in offspring were necessary
for natural selection to occur
C. Gregor Mcndel provided the most plausible hypoth­
esis for genetic s: Mendelian genetics: Two laws
were developed by using statistics to analyze results
of crosses inVOlving distinguishing traits of garden
peas
I - Law of Segregation of Alternate Factor s
Developed by Mendel using single-trait crosscs
A. Single-trait crossbreeding:
1. Two truc-breeding (those that consistently yield
the same form when crossed with each other) par­
ents (1' ,) but different strains were crossed (e.g.,
round versus wrinkled seed)
2. The offspring (F ,) from thi s cross all showed only
one trait (e.g., round seed) and thi s was called the
dominant trait; the traits from the parents did not
blend
3. The F, individuals were crossed with each othe r to
produce F, individuals
4. 3/4 of the F, expressed the dominant trait ; 1/4
ex pressed the trait of the other P, parent (e.g.,
wrinkled seed) which had not been expressed in
the F, generation and was thus recessive
13. Mendel 's crosses for single traits can be summari zed
as fo ll ows:
Mendel's I" Law: Segregation of Alternate Factors
Gray

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generati on

2. Metaphase I: Ilomologues line up at equator
3. Anaphasc J: Il omo logues separated into two
g roups, with each group having a mi xture of
maternal and paternal chromosomes
4. Tclophasc I: New haploid nuclei t()rming for
two new dau ghkr cell s
5. Intcrkines is: No replicati o n of DNA oCUlrs
because each chrom osom e is still duplicated and
co nsists of two chromatids (although cross ing
over results in some chromatids with maternal and
paternal segmenl s)
B. Meios is II

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Prophase II

Metaphase II Anaphase II 11..: Iopha sc II Four
dau g hte r

*Four new ce ll" a rc genet ica ll y unique and haploid. ce lls·

I. Prophase II: C hromosomes conlkn s.:
2. Metaphase II : Chromosomes line up at eq uator
3. Anap hasc II : C hromnt ids of cach chrom osome.
arc separated
4. Tclophase II : Each daughter ecll li·om Mei osis I
wil l fo rm two more ce ll s fo r a total o f lour cell s
Faunal/Flo ral Gametogenesis
A.ln animals, me iosis occurs ill germi na l tissues and is
called spe rmatogenes is in mal es and oogcn.:sis in
fcmales: each result s in a gamete
B. In plants the process is similar cxcc:pt that mitoti c
divi sions may fol low meiosi s 10 produce gametes
Gametogcnesis

Plant

I

M i J("i~

Mult icellular organism

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C7/ ~~)I \f'!1 !Il'f.

lemale (GG)

Normal male (gg )

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Galllctes
produced by
P ge neral ion

r,
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(ialllctcs limB 11) st'grcgaliun uf allele\) and inlii\ id ual
a S~ ortlllt:nt

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G() S~

(f ray,
, hort

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GgSI
Grav.
SllO ,' l

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Gametes



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Nor mal.
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F2

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a
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Gray. ,hon-haired
p
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All GgSs

Gametes

produced by

P generation


gl'llcration -

G. Polygeni c inhcritanCl': Many genes conlribute to
a ph enotype
7. Pleiotropy: Onc gene can efleet several ph.:notypcs
8. Environmental influcnces: Where the genotype
and environment interact to form a phenotype
II - Law of Independent Assortment
Developed by Mendel usi ng Illult ip le-trait crosses
A. Two true-breeding parents of diflc rc nt stra ins for 1\\0
traits we re crossed ; the F,'s were Ihen crossed, pro ­
ducing F, indi viduals
13. The results o f crosses invo lvin g two trait s can be
summarized as ta ll ows:
Mendel's 2"" Law: Indepcndl'nt Assortment

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ggS,
gg"
"lnrmal. ",,"ormal. n
\hort
long

.It
Ilt


(,ra) ,

long-haired

J

Normal.
long-haired

C. Mendel concluded stati stically thai these r.:sults

occ urred because a llel es for one tra it or gl: ne did not
atTect th e inh eritance of all eles fo r anolher trai t
All Gg

Gg

gg

~ lt lt

,
o
n

C. Mendel's first conc lusions: Disc rete factors (n ow

known as ge nes) were responsible for the tra il s a nd
the se fa ctors we re paired, separatecl (whi ch occ urs
during mei os is) and recombined (during fertili za­
tion) ; altern ate form s of fact ors or ge nes exist
ca ll ed all e les; the F, indiv idual s had two alkles,
th eir genotype consisted of a do minant and reces­
sive all ele (e. g ., Rr with R for roun d and r fo r wrin ­
kled seed); thus, the F,'s wcre hy bri ds; th eir pheno­
typ.: was similar to o nly onc of ori gin al pa re nt
(e.g., ro und seed)

Mendel Updat ed
A. Genes arc fo und on chromosomes , and thus ll1ultipl e
traits assort independentl y as long as they are locat­
ed on dilferent ch romosomes; Mendel stud ied traits
In peas that were each on separat e chromosomes;
gcnes on the same chromosome arc linked and thus
wiil not normally assort independcntly
B. I ntcral'tions bctween alleles:
I. C om plete dom in a nce: One all ele do mi nates
an other allele
2. In comp lete do mina nce: Neith er a ll ele is
expressed fu Ily
3. Codom inance : Both alle les a rc ex pressed fully
4. M ulti plc alleles: More than two all eles for a ge ne
are found within a popUlati on
5. Epistasis: One gene alters the affect of another gene
3

Chromosomes and Sex Determination.
A. In ma ny animal s, spec ial ch romoso mes determine
sex; the rcmaining chromosome, a r~ auto,,\J11CS
B. ln hUl11 a ns, Ih ere a rc 44 a ui oso ll1 Cs a nd Iwo sex
,n
c hro l11 os o l11e s: X and Y in l11 a les, X and
fe l11 a les
Sex Determi nation

EI
Mal e

Parenls

I cmalc

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Gametes ( ; / (

1

Y

~
Zygoles

Y
,'cmn lc

Male

Sex-Linked Traits
In hum ans, the Y chrol11 osol11e c nt ain s the determi­
na nt for ma le ness; the X con tains many genes; if a
malc gets a recessive (or dominant) allele on the X
chromosol11e from his mother, he will ex press the trait:
there fore, ma les arc frequently afllicted with X-linked
di sorders


Molecular Genetics

Population Genetics

Genes. DNA & Nucleic Acid

The Central Dogma

A. Gene functions:
I. To be pre~erved and transmitted
2. To control various biological functions through
the production of proteins (i.e., large, complex
sequences of amino acids) and RNA
B. Gene structure; two types of nucleic acids:
I. Deoxyrihonucleic acid (DNA)
2. Ribonucleic acid (RNA)
C. Nucleotides: The components of nucleic acids; three
sub units:
N ucleotides

A. Replication:
I. DNA is copied from other DNA by unzipping the
hel ix and pairing new nucleotides with the proper
bases (i.e., A with T and
with G) on each sepa­
rated side of the original DNA
B. Transcription:
I. Mes senger (m)RNA is copied from DNA by
unzipping a portion of the DNA helix that corre­
sponds to a gene
2. Only one side of the DNA will he transcribed and
nucleotides with the proper bases (A with U and
with G) will be sequenced to build pre-mRNA
3. Sequences of nucleotides called introns arc
removed and the remaining segments called exons
are sp liced together
4. The mature mRNA leaves the nucleus to be tran­
scribed by the
ribosomes
RNA Synthesis/Transcription

e

e

OH

H

H

NitrogenoLls
base

I. Sugar (deoxyribose in DNA; ribose in RNA)
2. Phosphate
3. Nitrogenous base (five possible bases)
a. In DNA, the nucleic acid of chromosomes, four
nitrogenous bases are to und: Adenine (A), gua­
nine (G), cytosine (e), and thymine (T)
b. RNA consists of similar bases, except uracil
(U) replaces thymine (T)
c. DNA is a double helix molecule: Similar to a
spiral staircase or twisted ladder, with the sides
tonned by repeating sugar-phosp hate groups
11'om each nucleotide, and the horizontal por­
tions (i.e. steps) formed by hydrogen bonds
involving A with T or e with G
d. Hereditary information : Genes found along
tile linear ~equence of nucleotides in the DNA
molecule
J)NA J)onble Helix

C. Translation:
I. Proteins arc syn­
thesized from
(m)RNA by ribo­
somes (which are
composed of
ribosomal
(r)RNA and pro­
teins) which read
from a triplet
eode (i.e.,
codons) that is
universal
2. The ribosomes
instruct transfer
(t)RNAs to bring
in spec ific amino
acids in the
sequence dictated
by the mRNA,
which in turn was
built based on the
sequence of
nucleotides in the
original gene por­
tion of the DNA

Genes in populations versus ind iv iduals
A. Populations evolve just as do spec ies
B. Genotype: Genetic composition of an indi vidua l
C. Gene Pool: Genetic composition of a population of indi­
viduals; that is , all alleles for all genes in a population
D. Evo lution involves changes in gene poo ls over time: to
undcrstand changes in gene poo ls as population s
evolve, an understand ing of non-evo lving popula­
tions is necessary

The Hardy-Weinberg Law
A. Both allelic frequencies and genotyp ic rati os (i.e ..
gene poo ls) rema in constant from generation to gen­
eration in sexua lly producing populations, if the fol­
lowing conditions of equilibriul11 exist:
I. Mutations do not occur
2. No net 1110ve l11ent of indiv idual s out of o r into a
population occ urs
3. All ollspring produced have the same chances fo r
survival, and mati ng is rando m; tha t is. no natural
se lect io n occurs
4. The population is largc so that chance would not
a ltcr frequencics of alleles
B. Algebraic equivalent of the Hardy-Weinberg Law :
1. p" + 2pq + q2 = I where
a. p = frequency of dominant allele
b. q = frequency of recessive allde
c. p2 = AA genotype
d. 2pq = Aa ge notype
e. q2 = aa genotype
C. Example:
I. If in a group of six indi vidual s there are nine domi­
nant (A) alleles and th ree reccssive (a) a ll cles. then p
= 9/ 12 or 0.75 and q = 3/12 Dr 0.25; a tota l o f 12
gametes will be produced. nine: of wh ich will hal'c the
dOl11inant allelc and three with the n:ccssivc allelc
2. Thc algebraic eq uation above can be used to predi ct
the ratios of the three poss ibl e gcnotypes as a resull
of 1ertilizat ions
a. Frequency of AA genotypes is p2 or (0.75)1 = 0.56
b. Frequency of Aa gen o types is 2pq or
2(0.7 5)(0.25 ) = 0. 38
c. Frequcncy of an genotypes is q2 or (0.25 )2 - 0.06
3. The frequencies of dominant and rccessivc alleles is still
the same--thc specific allclcs havc been redislIibuted

Hardy-Weinberg and natural populations
A. Few (if any) populations arc in equili brium:
therdu re. changes in allele frequcnci es a nd thus
genc poo ls do occur in natura l populations
B. Thc HMdy-Wei nberg Law he lps to identify the mech­
anism s of th ese evo lutionary changes by predicting
that one or more of the four conditions requi red arc
not met; that is:
I. Mutations occ ur
2. In dividua ls leave and enter populati o ns
3. o nrandolll mating a nd natural sc lccti o n occ ur
4. Sma ll popu lations exist

Allele Frequency Changes


Protein Synthesis

Frequency of allele

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Customer Hotline .
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ISBN - 13: 978 - 157222741-5
ISBN - 10: 157222741 - 9



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Mutations
Any random , permancnt change in the DNA molecule ;
many are harmful , some have no effect, and a few
actually benefit the organism; nature selects those
mutations that are bcneficial or adaptive in organisms
to help shape the course of evolution
4

tree
&
h u nd~wn
r::: AAad~
~ r ,·.s At
qUIC 5 udy.com
8



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