Fossils
What do fossils provide
lots of evidence for evolution
Name a set of fossils that is pretty good
the evolution of the horse
Describe evidence which supports the theory of Plate tectonics
That all the continents fit together like a puzzle, Matching fossils in Africa and south america, identical rock sequences, living creatures, and Wegeners theory of crustal movement.
Define Meiosis
is the process of cell division which creates sperm or egg cels
As the edges of the plates move what else moves.
The continents move
what do fossils show
How todays species have changed and developed over millions of years
When plants and animals don't turn into fossils what do they do
They decay
Where is the oceanic plate always forced and whats it called
underneath the continental plate, this is called the subduction zone
Where does meiosis happen
Happens in the ovaries or the testes, reproductive organs
At what speed are the plates moving
1cm or 2cm per year
where have Identical plant fossils of the same age have been found in rocks
South Africa, Australia, Antarctica, India, South America, this also strongly supported Pangaea
Why are there missing links for fossils
Because very very few dead plants or animals turn into fossils and that makes some fossil records incomplete
Best known example of plate sliding past each other is what
San Andreas Fault
Meiosis is another type of what?
Cell division
What 5 collision points where earths plates meet.
San Andreas Fault, Peru-Chile trench, Mid-Atlantic ridge, Marianas Trench, Japan trench
What two things do fossils found in rock layers tell us
what creatures and plants looked like and how long ago they existed
Who usually dates the fossils
Geologists
What happens with big plates of rock
They don't glide smoothly past each other, they catch each other and as the force builds up they suddenly lurch
Second step of Meiosis
the pairs now split up so the some of your fathers chromosomes go with some of your mothers chromosomes but there will be no pairs at all.
Name the 6 main plates
North american plate, South american plate, african plate, Nazca plate, antarctic plate, eurasian plate
Name three ways that fossils can be formed
From hard parts of animals, from the softer parts of animals or plants petrification, in places where no decay happens
Examples of hard parts of animals that are usually fossils
Things like bones, teeth, shells which don't decay easily also can last a long time when buried
What happens when the tectonic plates move apart
magma rises up to fill the gap and produce new crust made of basalt. Sometimes it comes out with great force producing undersea volcano
Third Step of Meiosis
The cells now split, with the chromosomes themselves splitting to from identical cells called gametes. The two armed chromosomes were already duplicates
Name the three different ways plates interact
Colliding, separating, or sliding past each other