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Natural sciences

Grade 8

Biodiversity

Module 23

Prehistoric life

For millions of years, life on earth consisted of microscopic single cell organisms only. True animals, like jellyfish and sponges, appeared about 700 million years ago.

They had soft bodies, but the development of shells, teeth and claws has made it possible for us to determine their appearance. How do we do this? By studying newly discovered fossils.

Finds of fossils dating from after the Cambrian period include animals like crocodiles and sharks.

Some animals quickly became extinct when conditions changed. Others were able to adapt and survive. Massive extinctions have occurred at various times in the history of the earth.

The age of the earth is counted in billions of years.

Find out more about this: Visit www.ucamp.berkeley.edu/exhibit/geology.html

Like clock time that is divided into hours, minutes and seconds, the history of the earth can be divided into four large “blocks”. We refer to these as AEONS. The first three aeons together are known as the Precambrian period. Our information about this period is scant because few fossils have survived to be studied.

The last period is known as the Proterozoic aeon. This aeon commenced approximately 540 million years ago and is divided into four eras.

The eras are divided into periods that might have lasted for 2 to 80 million years each.

Activity: to do research and to collect data

1. Explain what you understand by geological time:

2. Use the circle to illustrate geological time as described above.

3. What would have caused the massive extinctions referred to in the above passage?

4. Explain what fossils are.

5. How do you think scientists determine the age of the earth? Find out about carbon dating.

Research: carbon dating

6. Find out about EVOLUTION as documented.

  • Bear in mind that this is a sensitive topic and that not all people hold the same opinions. The scientist, however, has a duty to examine all phenomena and theories and to share his / her deductions with other people. Each individual can then decide whether he or she agrees or not. Make an informed decision!

Research: evolution

  • Search in google.com

Assessment of RESEARCH:

Could you find any information on carbon dating and evolution?

[ LO 1.2]

Assessment

Learning outcomes 1: Scientific investigations

The learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts.

This is evident when the learner

1.2 is able to conduct an investigation and collect data.

Memorandum

Activity: COMPREHENSION TEST AND RESEARCH

  • Preparation – read about carbon dating and find sources of information on evolution.
  • As well as mass extinctions.
  • Find appropriate video material.

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
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Source:  OpenStax, Natural sciences grade 8. OpenStax CNX. Sep 12, 2009 Download for free at http://cnx.org/content/col11050/1.1
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