Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
What is an astronomical unit?
|
(AU) The average distance between the Earth and the sun. Used for measuring distances inside the solar system. (150 million of Km)
|
|
|
What is a light year?
|
The distances travelled by light in one year. Used for measuring distances outside the solar system. (9460 billion km)
|
|
|
What is the general organizational stucture of the universe?
|
Visible unverse-----> supercluster of galaxies----->cluster of galaxies---->galaxy----->Star
|
|
|
What are the conditions required for the developpement of life?
|
1. A roughly circular orbit
2. An atmosphere 3. Ideal mass 4. Water 5. A lithosphere 6.ideal distance from the sun |
|
|
Why do we need a roughly circular orbit?
|
So that there is not to big of a shift in temp.
|
|
|
Why do we need an atmosphere?
|
To protect it's life from harmful solar radiation and makes the cycle of water possible.
|
|
|
Why do we need an ideal mass?
|
The larger the mass the higher the graviity so if it's too big it will crush you. If it's too light there is not enough gravity to hold gaseous particles that form an atmosphere.
|
|
|
Why do we need water?
|
It needs a large amount of liquid water which is essential to the reactions for the forming of molecules.
|
|
|
Why do we need a lithosphere?
|
Once the first molecules have formed, they need a solid surface to turn into more complex molecules.
|
|
|
What happened in the precambrian era?
|
-formation of rocks, oceans, atmosphere and continents which provoked the formation of life (prokaryotes) namely bacteria. Multicellular bacteria (blue-green algae) that goes throough photosynthesis which ledsto oxygen building up in the atmosphere. (4.6 to 540 mya)
|
|
|
What happened in the paleozoic era?
|
trilobites, fish and seaweed appear in the ocean. then life moved on land ; insects, amphibians and reptiles. The permian extinction cased 50% of land species to die off and 95% of marine life to die. Perhaps caused by widespread glaciation or volcanism. (540 mya to 65 mya)
|
|
|
What happened in the Mesozoic era ?
|
this area marked the reign of the dinosand the appearance of mammals, birds and flowering plants. the end is marked by a mass extinction of dinos and mammals. One of the theories is that earth was bombarded by asteroids sending clouds of dust making it impossible for most animals to live. (248 mya- 65 mya)
|
|
|
what hapenned in the Cenozoic era ?
|
This is where mammals ruled, they became larger and more diverse but died out in a mass extinction.
|
|
|
What is a fossil?
|
It describes all traces of life from the geological periods. Generally found in sedements and in sedimentary rocks (ex limestone and sandstone)
|
|
|
What are the steps of how fossils are formed?
|
1. organism dies
2. With soft tissue eaten or decomposed is coverd by a layer of sediment. 3.more and more layers add on 4.The entire layer hardens and preserves the fossil. |
