I need help can someone answer plz ? What similarities & what differences do you notice between purines and pyrimidines ?

What is the term for the two sets of chromatids formed in the parent cell a. haploid b. diploid c. gamete d. tetrad

Using meiosis, the sporophyte produces spores that are .

Which of the following is likely not involved in this example of ecological succession? a) the rotting remains of plants add to the fertility of the soil. b)the soil becomes so fertile that eel grass is replaced by other plant species. c) the roots from plants stabilize the sediment, keeping it in place. d) the concentration of salt becomes so high that all plant life is destroyed.