When mitosis occurs, the dna inside the cell's nucleus must replicate. the new cell that is formed has an identical copy of its parent cell's dna. that means it has the same information coded in its genes. during dna replication, how is an accurate new copy of dna formed? a. dna helicases add nucleotides to the exposed bases and ensure the formation of hydrogen bonds. b. replication forks ensure that dna polymerases cannot attach to the old dna molecule. c. during dna replication uracil bases hold the place of all thymine bases until the newly formed double helix is able to form hydrogen bonds. d. dna polymerases add nucleotides to the exposed base pairs according to base-pairing rules.

Ameadow ecosystem includes many species of grasses and small shrubs, several herbivores, and a few carnivores. a fungus colonizes the meadow and kills most of its vegetation. what is most likely to happen to the populations of herbivores and carnivores in the ecosystem? a. the populations of herbivores and carnivores will increase because there will be less competition for chemical energy. b. the populations of herbivores and carnivores will remain stable because the fungus cannot infect these organisms. c. the populations of herbivores will decrease because of vegetation loss, but the population of carnivores will remain stable. d. the populations of herbivores and carnivores will decline because less chemical energy will be stored in the ecosystem.

1) what three conditions must be present for minerals to form through natural processes? 2) why are minerals considered inorganic substances? 3) how do oxides differ from other minerals that contain oxygen atoms? 4) how is a sulfide different from a sulfate? what makes native elements unique?

How does secondary succession differ from primary succession?