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Natuurwetenskappe

Lewe en lewenswyse

Opvoeders afdeling

Memorandum

Erdwurm:

1. Omdat dit dooie materiaal in die grond indra, die grond los maak (gasse en water kan inkom), as voedsel vir ander diere dien.

2. Omdat die vel vogtig en sag is vir asemhaling. Die liggaam kan dus vinnig uitdroog, en asemhaling kan nie deur ‘n droë vel plaasvind nie.

3. Omdat dit diere soos die erdwurm kan laat vrek. Dan kan die grond hard word en water, gasse en dooie materiaal sal nie meer kan inkom nie: die grond gaan onvrugbaar word.

Leerder afdeling

Inhoud

AKTIWITEIT: Om inligting oor die erdwurm te interpreteer [LU 2.1, LU 2.3]

DIE ERDWURM

Die erdwurm is deel van ‘n groep wat as gesegmenteerde wurms bekend staan.

Dit is belangrik dat jy die erdwurm leer ken, aangesien hierdie diertjie ‘n belangrike rol in die ekosisteem speel.

Kom ons kyk hoe sy liggaam by sy leefwyse aangepas is.

Liggaamsbou

Die erdwurm is ongeveer 150 mm lank en die hele liggaam bestaan uit ringvormige segmente wat elk ongeveer 1 mm dik is.

Aan die voorste punt is daar ‘n mond met ‘n klein lippie waarmee voedsel in die mond ingestoot word. Op die agterste punt is die anus waar voedselreste die liggaam verlaat.

Op al die segmente, behalwe die eerste en laaste, is daar haartjies wat die wurm help om deur die grond te beweeg.

Beweging

Die erdwurm beweeg deurdat spiere in die segmente saamtrek en verslap waardeur die liggaam lank en dun word en dan weer kort en dik. Die haartjies op die segmente skop teen die grond vas en die wurm beweeg vorentoe.

Voeding

Die erdwurm kom in die nag uit die grond uit en trek met die lippie voor sy mond verrottende plantmateriaal in sy tonnel in. Hy vreet ook grond soos hy sy tonneltjies deur die grond grawe.

Asemhaling

Die erdwurm haal deur sy vogtige vel asem. Dit is dus belangrik dat die vel vogtig bly en die wurm is dus afhanklik van ‘n vogtige omgewing.

Handhawing van ‘n waterbalans

Die erdwurm het ‘n ingewikkelde stelsel van buisies in sy liggaam met openinge na buite waarmee hy die hoeveelheid water wat sy liggaam opneem en afgee, beheer sodat die regte balans gehandhaaf word.

Voortplanting

Twee erdwurms lê teenmekaar en ruil geslagselle uit. ‘n Slymkokon vorm om hulle liggame en die geslagselle bly in die kokon agter wanneer dit van die liggaam afskuif. Die kleintjies broei in die kokon uit en lyk onmiddellik nes hul ouers.

Opsommend: die erdwurm in die ekosisteem

1. Die erdwurm speel ‘n belangrike rol in die ekosisteem omdat hy ... (gee twee redes)

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

2. Die erdwurm is afhanklik van ‘n vogtige omgewing omdat _________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

3. As ons gif gebruik om peste te bestry, kan dit die grond benadeel omdat

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

Assessering

Leeruitkomste 2: Die leerder ken, interpreteer en pas wetenskaplike, tegnologiese en omgewingskennis toe.

Assesseringstandaard 2.1: Dit is duidelik wanneer die leerder betekenisvolle inligting onthou: onthou, ten minste, definisies en komplekse feite;

Assesseringstandaard 2.3: Dit is duidelik wanneer die leerder inligting interpreteer: interpreteer inligting deur kernidees in die teks te identifiseer, patrone in aangetekende data te vind en gevolgtrekkings te maak uit inligting in verskeie vorme (bv. prente, diagramme en geskrewe teks).

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
why?
Adin
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
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Source:  OpenStax, Natuurwetenskappe graad 7. OpenStax CNX. Sep 16, 2009 Download for free at http://cnx.org/content/col11078/1.1
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