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Natural sciences

Life and way of living

Educator section

Memorandum

Earthworm:

1. It takes dead matter into the soil, loosens the soil (aerates the soil / makes it possible for gases and water to enter the soil), serves as food for other animals.

2. The outer covering is moist and soft for respiration. The body therefore dries out very easily and respiration cannot take place through the dried-out skin.

3. It can kill animals like earthworms. This will result in the soil becoming hard and dry and water, gases and dry material will not enter the soil: the soil will become infertile.

Leaner section

Content

Activity 7: to interpret information about the earthworm [lo 2.1, lo 2.3]

The earthworm

The earthworm is part of a group that is known as segmented worms .

It is important that you get to know the earthworm, as this small animal plays a very important role in the ecosystem.

Let us look at how its body is adapted to its way of life.

Build

The earthworm is approximately 150 mm long and the whole body consists of ring-shaped segments, each approximately 1 mm thick.

At the front tip there is a mouth with a small lip with which food is pushed into the mouth. At the back tip is the anus , where the remains of the food leave the body.

On all the segments, except the first and the last, there are hairs that help the worm to move through the soil.

Movement

The earthworm moves by means of muscles in the segments that contract and relax, causing the body to become long and thin, and then short and thick. The hairs on the segments press against the soil and the worm then moves forward.

Feeding

The earthworm comes out of the ground at night and pulls rotting plant material into its tunnel with the help of the lip in front of its mouth. It also eats the soil as it tunnels through the ground.

Respiration

The earthworm breathes through its moist skin. It therefore is important that the skin remains moist, as the worm is dependent on a moist environment.

Maintaining a water balance

The earthworm has a complex system of tubes in its body with openings to the outside by which it controls the quantity of water that its body absorbs and excretes so that the correct balance is maintained.

Reproduction

Two earthworms lie next to one another and exchange sexual cells. A slime cocoon forms around their bodies and the sexual cells remain in the cocoon when it slips off the bodies. The young hatch in the cocoon and immediately look just like their parents.

In summary: the earthworm in the ecosystem

1. The earthworm plays an important role in the ecosystem because it … (give two reasons)

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2. The earthworm is dependent on a moist environment because _________________

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3. If we use poison to combat pests, it can be disadvantageous to the soil because

_____________________________________________________________________

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_____________________________________________________________________

_____________________________________________________________________

_____________________________________________________________________

Assessment

Learning Outcome 2: The learner will know and be able to interpret and apply scientific, technological and environmental knowledge.

Assessment Standard 2.1: We know this when the learner recalls meaningful information (at least definitions and complex facts);

Assessment Standard 2.3: We know this when the learner interprets information.

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
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Natural sciences grade 7. OpenStax CNX. Sep 16, 2009 Download for free at http://cnx.org/content/col11077/1.1
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