4.5 Populations

8/11/2019 4.5 Populations

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4.5 FACTORS CONTROLLING POPULATION SIZE

1. Ecosystems are dynamc and s!"#ect to c$an%e.

&. Canddates s$o!'d "e a"'e to de(ne t$e term )*o*!'aton+.Number of Organisms of the same species in one given area.,. Po*!'aton n!m"ers -'' !ct!ate and t$s s de*endent on /aro!s0actors.

Biotic/Abiotic Factors (10-12)For a specic popu!ation" there is a #$% &O'N%" A certain eui!ibrium popu!ation thatthe environment can support for. &opu!ation Osci!!ations are regu!ate b* N$+A%',$F$$BA.4. Po*!'aton n!m"ers are de*endent on t$e "rt$ and deat$ rates andmm%raton nto t$e *o*!'aton and em%raton a-ay.Once a popu!ation is estab!ishe" the groth of that particu!ar popu!ation isetermine b* the birth an eath rates. oever" iniviua!s can !eave an entera popu!ation ($cept 3icrobes uner Aseptic onitions). 'mmigration is themovement of iniviua!s 'N%O a popu!ation" hi!st emigration is the movement O4%of a popu!ation. 3igration is perioic" $migration is one a* process. Overcroingan other factors ma* act as a stimu!us for $migration.5. Po*!'atons -'' ncrease n s2e -$'st deat$ rate s 'o-er t$an "rt$rate.5og &hase3. Some 0actors -'' s'o- do-n *o*!'aton %ro-t$ rate and some -''ca!se a *o*!'aton cras$.#igmoi curve 6 #hos e7ect of !imiting factors 8 urve 6 No 5imiting Factors " atastrophic ec!ine 6 BOO3 or B4#%.. Canddates s$o!'d "e a"'e to dra- a %enera'sed %ra*$ o0 *o*!'aton%ro-t$ s%mod %ro-t$ c!r/e6 and 'a"e' t$e sta%es o0 %ro-t$ as s$o-n

"y a '7!d c!'t!re o0 yeast or "actera.5ag &hase 6 5itt!e or no ce!! groth- %ime for a9usting/aapting to meium-creating the essentia! en:*mes neee-&rotein #*nthesis

5og &hase 6 $ponentia! e!! +roth-&!entifu! supp!* of Nutrients-No 5imiting Factors

#tationar* &hase 6 e!! groth ; e!! eath-$ui!ibrium beteen birth an eath

estab!ishe

-one or more !imiting factor(s) in p!aceeath phase 6 ecrease in Numbers

-*ing < Birth.-'ncreasing !imiting conitions-averse conitions.

8. Canddates s$o!'d "e a"'e to *'ot %ra*$s o0 *o*!'aton %ro-t$ rate-$en *ro/ded -t$ a**ro*rate data.

9. Canddates s$o!'d "e a"'e to nter*ret %ra*$s o0 c$an%es n *o*!'aton%ro-t$ rate.

1:. ;eat$er *redaton *arastsm dsease6 0ood s!**'y '/n% s*ace andcom*etton may a<ect *o*!'aton %ro-t$.$nvironmenta! =esistance 6 Factors hich a7ect popu!ation groth



11. T$e e<ect o0 densty de*endent 0actors /ares -t$ t$e s2e o0 t$e*o*!'aton -$ereas t$e e<ect o0 densty nde*endent -'' "e t$e samere%ard'ess o0 t$e *o*!'aton s2e .ensit* epenent 6 ,ar*ing $7ectsepenent on the si:e of thepopu!ation

-isease B-&arasites B

-Foo #upp!* B-ompetition B

ensit* 'nepenent 6 #ame $7ectsirrespective of popu!ation si:e.

->eather A-%emperature A-F!oos/rought A

-abitat isruption. A

Biotic Factors 6 5','N+Abiotic Factors 6 NON 5','N+1&. Canddates s$o!'d "e a"'e to de(ne t$e term )carryn% ca*acty+=e>*'an $o- t$s s de*endent on t$e a/a'a"'ty o0 reso!rces -$c$t$ere0ore act as densty?de*endent 0actors6= $o- *o*!'atons m%$t t$en!ct!ate a"o!t t$s set *ont.arr*ing apacit* 6 5imit to the number of iniviua!s an area can support.

-'t has reache its maimum si:e ue to !imiting factors1,. Canddates s$o!'d "e a"'e to descr"e t$e re'at/e ad/anta%es and

dsad/anta%es o0 c$emca' and "o'o%ca' contro' n terms o0 e@cencyen/ronmenta' dama%e ease o0 !se and e<ects on $!man '0e.

A,AN%A+$# '#A,AN%A+$#

B'O5O+'A5

ON%=O5

-igh!* #pecic-5ong %erm (once$ui!ibrium $st.)-'nepensive in the 5ong %erm ($pensive to startup)-No $nvironmenta!

ontamination-an be use in g!asshouses

-#!o to bui! up in number-=e!ative!* fe successfu! eamp!es-$pense 6 igh 5eve! of #?i!! Neee-etai!e no!ege of the !ife c*c!eneee-Agents aren@t ?non for a!! pests-Freuent input neee

-5itt!e use to iniviua! proucers.

$3'A5ON%=O5

-$7ective-uic?-=e!ative!* heap-#ma!! #ca!e-5o #?i!! 5eve! Neee

-Non #pecic ; &otentia!!* eraicatebenecia! insects-&otentia! resurgence of the pest-3a* become resistant to pesticie-3a* i!! Fish/Birs/3amma!s-5ong %erm $posure harm umans.

14. T$e ad/anta%es o0 c$emca' contro' nc'!de ra*d eradcaton o0 a *est

o/er a s*ec(ed 'oca'sed area and re'at/e cost e<ect/eness. T$edsad/anta%es nc'!de t$e de/e'o*ment o0 resstance and to>cty rss tonon tar%et or%ansms.

15.T$e ad/anta%es o0 "o'o%ca' contro' nc'!de ts s*ec(cty -t$ noresstance and no en/ronmenta' dama%e or resd!es. A dsad/anta%e st$e nta' cost o0 t$e researc$ re7!red to e/a'!ate t$e a%ent+s "o'o%y norder to ntrod!ce ade7!ate n!m"ers nto t$e *est *o*!'aton at t$eo*tm!m tme. Gro-ers m!st "e con/nced t$at *re/enton o0 (nanca''oss does not re7!re com*'ete eradcaton "!t t$at t$e mantenance o0

contro' may necesstate re*eat a**'caton.



13. Canddates s$o!'d !nderstand -$at s meant "y or%anc "reado-nand descr"e ts m*ortance to t$e ecosystem nt$e recyc'n% o0 mnera' n!trents.hemica! e!ements are avai!ab!e on!* in 5'3'%$amounts" an so !ife epens on the rec*c!ing of essentia! chemica! e!ements.1. Bcroor%ansms *'ay an m*ortant ro'e nt$e *rocess o0 decay re'easn% com*o!nds o0

essenta' c$emca' e'ements 0rom t$e "odes o0 dead or%ansms.

18. Canddates s$o!'d "e a"'e to dra- a'a"e''ed da%ram o0 t$e car"on cyc'e 'nn% t$e*rocesses o0 *$otosynt$ess res*ratondecom*oston 0oss'saton and com"!ston'n to 5.86.&hotos*nthesis

- &!ants ta?e up O2 an use it to ma?e sugars=espiration

-Brea?on of #ugars to re!ease energ* an prouce O2 as a b* prouctecomposition

-Bacteria an Fungi brea? on ea an eca*ing matterFossi!isation

-&!ants an Anima!s ie but on@t eca*. Action of heat an pressure overmi!!ions of *ears create fossi!s/fossi! fue!sombustion

-ar $ngines/Factories etc. Burn the Fossi! Fue!s an re!ease the O2 bac? intothe environment19. Ntro%en s 0o!nd n a'' amno acds 0rom -$c$ *rotens are made.

Ntro%en s a/a'a"'e to *'ants on'y n t$e 0orm o0 ammon!m and ntrateons= t$ese ons "en% taen !* "y t$e roots.Nitrogen is neee to ma?e Amino Acis" Nuc!eic acis an &roteins.&:. Canddates s$o!'d 'n t$e !*tae o0 ntrates -t$ *roten synt$essand t$e synt$ess o0 n!c'ec acds.

&1. T$e ntro%en cyc'e s t$e o- o0 or%anc and nor%anc ntro%en -t$nan ecosystem -$ere t$ere s an nterc$an%e "et-een ntro%eno!scom*o!nds and atmos*$erc ntro%en.

&&. T$e man *rocesses o0 t$e ntro%en cyc'e are *!tre0acton

ntr(caton ntro%en (>aton and dentr(caton.&utrefaction

-Bacteria an Fungi ecompose eap!ants an anima!s" faeces an urine intoammonium ions ( N

C).Nitrication

-Ammonium is converte to Nitrites"then Nitrates b* Nitrif*ing Bacteria. %heseBacteria reuire A$=OB' conitions.Nitrogen Fiing

-Atmospheric Nitrogen is convertestraight to nitrogen compouns b* nitrogening bacteria. %here are Free 5iving an#*mbiotic Nitrogen Fiing Bacteriaenitrication



- Nitrogen is !ost from the $cos*stem b* enitrication. %his is a prob!em inater!ogge soi!s. %his reuires ANA$=OB' conitions.&,. Canddates s$o!'d e>*'an t$e act/tes o0 ntr0yn% dentr0yn% andntro%en?(>n% "actera and s$o!'d no- t$e %enerc namesNitrosomonas Nitrobacter Azotobacter and Rhizobium.Nitrobacter 6 Nitrication 6 Nitrites to NitratesNitrosomonas 6 Nitrication 6 Ammonium to NitritesA:otobacter 6 Nitrogen Fiing 6 Nitrogen to Ammonium DFree 5iving

=hi:obium 6 Nitrogen Fiing 6 Nitrogen to Ammonium D#*mbiotic in the root nou!esof 5egumous p!ants.&seuomonas 6 enitrif*ing 6 Nitrates to Nitrogen

&4. P'o!%$n% and drana%e are m*ortant n aeraton o0 t$e so'*rod!cn% t$e aero"c condtons re7!red "y ntr0yn% "actera.enitrication reuires ANA$=OB' conitions. %his means that in ater!oggesoi!s" enitrication is favoure more than nitication" an soNitrates/Nitrites/Ammonium is converte bac? to atmospheric nitrogen.umans can a!so improve the circu!ation of Nitrogen b*

-Fiing atmospheric nitrogen articia!!* using chemica! processes that convert

it to ferti!i:er-!arge amounts of anima! aste use as manure-#eage isposa!s boost Nitrogen #upp!ies-Farming &ractices such as

-&!anting e!s ith !over (!egumous p!ant) to encourage nitrogening

-raining !an an reucing anaerobic conitions-&!oughing e!s in orer to improve aeration of the soi!.

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4.5 Populations