The Krebs cycle occurs in the mitochondria. There are nine biochemical reactions involved in the Krebs cycle and they are highly ordered. Select the correct order from the following choices. Note these are abbreviated and do not show NAD, ADP, ATP, FAD, or water.
Acetyl - CoA joins the Krebs cycle and unites with oxaloacetate forming citrate which forms isocitrate which forms alpha-ketoglutarate which forms succinyl - CoA which forms succinate which forms fumarate which forms malate which forms oxaloacetate

the answer would be 3

humans are now responsible for causing changes in the environment that hurt animals and plant species. we take up more space on earth for our homes and cities. we pollute habitats. human activity often changes or destroys the habitats that plants and animals need to survive.

the fossil record provides evidence of a common ancestor to many species.

this age may represent the age of the earth's accretion, of core formation, or of the material from which the earth formed. this dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.