Can you answer number 12 il give all my points

The following image is of a diatom. it lives in water and gets food from photosynthesis. it is encased in a hard shell made of something similar to glass or sand . a diatom is a(n) because it has a) multi-celled organism; specialized parts. b) vertebrate; a skeleton. c) insect; an exoskeleton. d) single-called organism; only one cell.

After fertilization, which type of cellular division is responsible for the growth and development of a complex, multicellular organism?

As a result of wildfires, in grasslands. a) tree growth increases b) grass growth increases c) soil quality decreases d) invertebrate variety decreases