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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

Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
LITNING Reply
what is a peer
LITNING Reply
What is meant by 'nano scale'?
LITNING Reply
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
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
hi
Loga
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit 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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