Which materials are composed of DNA? (1) proteins
(3) nerve secretions
(2) genes
(4) fluid in vacuoles

The correct answer is (2) genes.

In biology, gene refers to the unit of heredity that is passed from the parent into the offspring. It is composed of small sections of DNA that code the genetic instructions or information.

c. heat from the poles back down towards the equator.

all these collisions do one thing, and that thing is explained in the last option. when dusst, rocks and ice collide, they harden and form giant layers of rocks or hard ice.

d)   to harden materials to form different parts of earth’s layers

hope it ,

bioteacher101