What did scientists like Darwin use to group species before DNA? two sentences, please!

They used to group organisms by watching their physical characteristics. For example animals with spines are grouped into vertibrates and organisms without spine are grouped into invertebrates . They also group organisms based on habitatats ( where the organisms live) . For example marine animals live in water and terrestrial organisms live in land. They grouped organisms based on their feeding behaviour. For example producers produce their own food.

the answers are as following:

1. c. double helix, nucleosome, coil, supercoil, chromosome

2. b. g2 phase, preparation for mitosis

3. d. interphase consists of the g1, s, and g2 phases

4. c. metaphase

5. a. chromosomes are duplicated before cell division so that each new daughter cell has a complete set

im not intirely sure but i think the anwser is d relative humidity