D an ecological footprint
DNA gets compact only during cell division and are called chromosomes. On other conditons, it forms a network of thin threads called chromatin network.
Explanation:
Tests for gases
Hydrogen, oxygen, carbon dioxide, ammonia and chlorine can be identified using different tests.
Hydrogen. A lighted wooden splint makes a popping sound in a test tube of hydrogen.
Oxygen. A glowing wooden splint relights in a test tube of oxygen.
Answer:
Homologous structures provide evidence for common ancestry