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Biology extinction hw
Due: 17th December 2013
Life first began on earth 3.5 ………….
years ago (b)
Biologists believe all life evolved from
simple life forms in the …….. (o)
These provide evidence of early life
forms (f)
The parts of an organism that don’t
easily decay and form fossils (h)
Name: …………………………………………
Red squirrels are threatened with
extinction because grey squirrels are
better at ……………. For food (c)
Ash trees are threatened with extinction
because they are being attacked by a
…………(d)
There is some evidence that dinosaurs
became extinct due to a massive……. (m)
Archaeopteryx is a fossil which is
part…… and part ……. (b & d)
The parts of organisms that do easily
decay and tend not to form fossils (s)
A term that means “the development of
a new species” (s)
These can form when part of an
organism is replace by stone or minerals
(f)
A group of organisms that can
interbreed to produce fertile young (s)
2 examples of traces of organisms
that can form fossils (f, b)
Lions and tigers can’t make fertile young
so they are considered different …..(s)
Scientists can’t be sure how life began
on earth as there is very little ……… of
the first life forms (e)
A way that 2 populations of a species
can become separated (g)
If organisms are trapped in an
environment with no oxygen they cannot
do this (d)
For natural selection to happen there
must be more than one of these within a
population (a)
Polar bears are threatened with
extinction due to changes to their
…….(e)
A process where organisms with alleles
that control favourable characteristics are
more likely to survive (ns)
(20 marks)
Can’t fit this question on here…. Please go to page 3!
Lexie Munro 2012
Total………………. (max 24 + 5 for stretch)
Biology extinction hw
Due: 17th December 2013
Name: …………………………………………
3. STRETCH
Scientists believe that 50,000 years ago the Death Valley region of the USA had a rainy climate
which produced an interconnecting system of freshwater rivers and lakes filled with fish. Around
10,000 years ago changes in climate resulted in these lakes partly drying up, forming many
separate small pools, each with fish in. Scientists believe the fish once shared a common
ancestor but have now become separate species. Explain how the fish have “become” separate
species.
………………………………………………………………………………………………………………
………………………………………………………………………………………………………………
………………………………………………………………………………………………………………
………………………………………………………………………………………………………………
………………………………………………………………..…………………………………(5 marks)
Lexie Munro 2012
Total………………. (max 24 + 5 for stretch)
Biology extinction hw
Due: 17th December 2013
Name: …………………………………………
2. The diagram below shows the evolutionary tree for a group of organisms called primates.
The names of extinct animals are printed in italics eg Nycticeboides
The drawings show animals that are alive today.
a) How many million years ago did Karanisia first appear?
………………………… millions of years ago (1 mark)
b) During which geological time period did the Apes and Monkeys begin to evolve?
(1 mark)
c) Which group of primates alive today are the closest relatives of the Lorises?
(1 mark)
d) Suggest one reason why primate species become extinct
(1 mark)
Lexie Munro 2012
Total………………. (max 24 + 5 for stretch)