Answer:
Option D.
Explanation:
The above answer given is incorrect. Nucleotides consist of a phosphate group attached to a pentose sugar, with 5 carbons, (deoxyribose sugar in the case of DNA) and the pentose sugar is also attached to a nitrogenous base. DNA is incorrect as nucleotides are the building block of DNA hence DNA is NOT a component of nucleotides.
Complex molecules are made up of other elements bonded with carbon. Carbon is able to bond with other molecules so easily because it has four valence electrons.
Answer:
2) End Triassic
Explanation:
End Triassic extinction occurred 201 million years ago. It was caused by the rifting of super continent Pangea. Pangea started to break and drift apart. When North america started to separate from Africa, volcanic activity increased. Lava and a large amount of gas was released into the atmosphere specially carbon dioxide. This led to global warming like condition which ultimately caused extinction of a large number of species.
