Science evolution test Tuesday June 10 AIM 27

What are the 7 characteristics of life

1 ability to grow and reproduce

2 extract and use energy from the environment

3 everybody requires water

4 have to be able to perform metabolic activities - cellular respiration

5 must have cell membrane

6 must contain carbon

7 ability to react and adapt to your environment

Age of earth and whip figured it out

Lord kelvin - was the first to try to figure the age of earth out.

He knew the earth was made out of molten rock

He said if you know how fast rocks cool you can tell how old earth is

He said earth was 20 - 40 million years old

What was wrong in his calculations

1 He did not take into consideration that rocks cool at diffrent speeds due to surroundings

2 he did not take into account convection current

What is convection current

Convection current occurs when hot air rises and cold air sinks

meteorites

scientists are able to calculate when meteorites were hitting earth

From from this information were able to calculate the earth 4.55 billion years ago

When does radiation occur

occurs when an object gives off heat

Step 1- 4.55 BYA

4- 4.55 BYA meteors stopped hitting earth this allowed for life to take hold

step 2 -3.5 BYA

3.5 bya chemosynthetic bacteria uses the earths energy to make food and oxygen

step 3 -3.5 BYA

3.5 BYA photsynthetic bacteria

Step 4 2.3 BYA

2.3 BYA the atmosphere was now rich in oxygen and those who could not use oxygen began to die out

Heterotrophic unicellular organisms used the oxygen and made carbon dioxide

step 5 - 1.5 bya

Multicellular protists that use carbon dioxide made oxygen

step 6 - 530 Mya

plants arrive on land

Step 7 - 370 MYA

first vertebrae’s walk on land

step 8 - 230 Mya

dinosaurs ruled the earth

Step 9 - 2 MYA

First humans walk on earth about 3 feathers tall

Urey miller experiment

proved that life on earth could arise from the primitive atmosphere

They mixed methane gas, ammonia, water and hydrogen gas along with an electrical; spark to demonstrate how life could have started on earth

Molecular evidence proved the idea of unity if life

A- carries those instructions to ribosomes where Protiens are made

B- the instructions for what Protiens are made

C. Share the same

D. Found in all cell membranes

E. Is the energy molecule for all living things