The two strands of a dna double helix are held together by

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.

Describe your dna model. which part do the straws represent? the pushpins? the paper clips and the black dots you made with the marker?

When ash and dust begin to settle on the ground, they eventually become compacted by