Carbon Isotopes and Their Role in Paleoclimate Studies

What distinguishes isotopes of the same element from each other?

• Different atomic numbers

• Different number of protons

• Different number of neutrons

• Different number of electrons

Why can't carbon-14 be used in stable isotope ratios?

• It has too many protons

• It is too abundant

• It is not found in nature

• It is radioactive and decays

How do plants affect the carbon isotope ratio in the atmosphere?

• By converting carbon-12 to carbon-13

• By releasing more carbon-13

• By absorbing more carbon-14

• By taking up more carbon-12

What is the difference in carbon isotope discrimination between C3 and C4 plants?

• C3 plants discriminate more against carbon-13

• C4 plants do not discriminate against carbon-12

• C4 plants take up more carbon-12

• C3 plants take up more carbon-13

How can fossil fuels indicate past biological activity?

• By their light isotopic signatures

• By their carbon-14 content

• By their nitrogen content

• By their color

What role do ice cores play in studying ancient atmospheres?

• They contain fossilized plants

• They are formed from volcanic ash

• They trap ancient air bubbles

• They are rich in carbon-14

How do calcium carbonate skeletons help in paleoclimate studies?

• They preserve carbon and oxygen isotope ratios

• They dissolve in water

• They are unaffected by environmental changes

• They are only found in modern organisms

What is the significance of stromatolites in carbon isotope studies?

• They are formed by volcanic activity

• They are made of pure oxygen

• They preserve photosynthetic activity signatures

• They are only found in freshwater

What information can carbonate nodules provide?

• Fossilized animal remains

• Past volcanic activity

• Ancient soil composition

• Rain or groundwater conditions

How does palynology contribute to understanding past climates?

• By studying rock formations

• By analyzing pollen and algae

• By measuring volcanic ash

• By examining fossilized bones