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Exercises

Question 1

  1. In each of the following cases, write down the LETTER of the most correct alternative:
    1. Which of the following fossils have been found in Namibia ?
      1. Mammal-like reptiles
      2. Glossopteris leaves
      3. Soft-bodied animals
      4. Early mammals
    2. What was the importance of stromatolites ?
      1. They released oxygen into the air.
      2. They absorbed oxygen and prevented animals being poisoned.
      3. They are the closest ancestors of modern plants.
      4. They were algae trapped in sediment.
    3. A problem in determining the accuracy of radiometric dating is that
      1. scientists are not sure that radioactive decay actually occurs.
      2. the decay rate of the minerals can change without warning.
      3. the rocks that contain the fossils can’t be dated.
      4. only organic samples can be dated radiometrically.
    4. Continental drift accounts for the fact that people have found …
      1. fern-like fossils in Africa.
      2. the fossils of subtropical plants in Antarctica.
      3. tectonic plates under the continents.
      4. trilobite fossils in almost all continents.
    5. Which statement below DOES NOT apply to the Paleozoic era?
      1. Trilobites and algae were the dominant life forms.
      2. Coal swamps were formed in many areas.
      3. It started with the Cambrian explosion.
      4. Birds developed during this era. [10]

Question 2

Match the terms in the first column with the phrases / descriptions in the second column. Write down only the correct LETTER next to the question number:[5]

Questions Column 1 Column 2
2.1 Mesozoic era A ancestor of frogs and fish
2.2 Coelacanth B are ancestral insect forms
2.3 Therapsids C are always solid fossils
2.4 Cast fossils D very superficial fossil imprints
2.5 Trace/ film fossils E early mammals developed
F are always hollow fossils
G ancestral to birds and dinosaurs
H have advanced palates and ear bones

Question 3

Give the correct biological TERM for each of the following. Write down only the question number and the answer.

  1. The era during which ferns and cycads were the dominant plants
  2. The ancient supercontinent
  3. A scientists who studies fossils
  4. The type of rock that may contain fossils
  5. An ancient fish type found in very deep water at Sodwana Bay [5]

Question 4

Examine the two images below:

  1. Suggest THREE things that fossil footprints like those in picture A can tell scientists about the animal that made them.(3)
  2. Identify the fossil in picture B. (1)
  3. Explain briefly how this fossil was formed.(8)
  4. What can we conclude about the area where this fossil is located millions of years ago? Give a reason for your answer.(2)
  5. Why is it that fossils are not found in igneous rock?(2) [16]

Question 5

Examine the fossil and graph below and answer the questions:

  1. To which class of the Chordata does the fossil shown here belong? Choose from: Pisces, Amphibia, Reptilia, Aves or Mammalia.(2)
  2. What does the term the “half life” of a radioactive element mean? (2)
  3. When the fossil was subjected to radiometric dating, it was found to contain 90% Uranium. If the half life of Uranium 235 is 704 million years, how old is thisfossil? Show all your working.(4)
  4. If another fossil was found and dated to 1408 million years, how much Uranium did it contain? Explain how you obtained your answer. (5) [13]

Question 6

Read the information below and answer the questions: Therapsid fossils from the late Permian have been found in South Africa. These animals had teeth differentiated into incisors, canines and molars, unlike reptilian teeth, which are all the same. Their legs were held more vertically, i.e. under the body, compared to what is usual in reptiles. It seems that they survived into the Mesozoic, but died out when the dinosaurs became to dominant life form.

  1. Where in South Africa have therapsid fossils been found?(1)
  2. Tabulate TWO ways n which therapsids are different from reptiles. (5) [6]

TOTAL 55

Suggested answers

Question 1

  1. C
  2. A
  3. C
  4. B
  5. D[10]

Question 2

  1. E
  2. A
  3. H
  4. C
  5. D [5]

Question 3

  1. Mesozoic
  2. Pangaea
  3. Paleontologist
  4. Sedimentary
  5. Coelacanth[5]

Question 4

  1. Mark 1st 3 only: Animal’s species, approximate length of leg, stride length approximate body weight, speed it moved at(3)
  2. part 2
    1. Ammonite
    2. Ammonite died, sank into mud. Mud was covered by more sand and excluded oxygen. Body decayed, shell was slowly mineralized over time. Mud was compressed andbecame harder, turning to stone. Later uncovered by erosion. (max 8)
    3. It was under the sea. Ammonites were marine creatures(2)
  3. Igneous rock is volcanic - lava is too hot to preserve fossils OR heat from lava destroys remains of animals(2) [ 16]

Question 5

  1. Amphibia(2)
  2. The amount of time needed to reduce the amount of (parent) element to half of what it was (OR the time needed for half of the element to decay / break down)(2)
  3. 0,2 x 704 million = 140,8 million years(4)
  4. 1408 million years ÷704 million years = 2 half lives, so the fossil had 25% Uranium 235.(5) [ 13]

Question 6

  1. Karoo(1)
  2. Table comparing therapsids and reptiles : (5) [6]
Therapsid Reptile
Specialized teeth (or explain) Legs held under body All teeth look the sameLegs out to the sides

TOTAL 55

Questions & Answers

where we get a research paper on Nano chemistry....?
Maira Reply
what are the products of Nano chemistry?
Maira Reply
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
Google
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
Preparation and Applications of Nanomaterial for Drug Delivery
Hafiz Reply
revolt
da
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
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
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
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
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
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Good
why and for what was five kingdom of classification of organisms introduced
SUBHIKSHA Reply
give the ans as fast as possible
SUBHIKSHA
Comment on the ozone depletion over the period of 1982 to 1996
Mpho Reply

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Source:  OpenStax, Siyavula: life sciences grade 10. OpenStax CNX. Apr 11, 2012 Download for free at http://cnx.org/content/col11410/1.3
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