DNA is composed of nucleotides, which are composed of three parts:
1. A five carbon carbohydrate (pentose)
Pentose is classified as a monosaccharide (simple carbohydrate), and its molecular formula is represented by 
. They are water soluble molecules with sweet taste. Monosaccharides may have from three carbon atoms (trioses) to six (hexoses). In DNA is present pentose (5 carbon atoms)
2. A nitrogenous base
Nitrogenous bases are ring-shaped compounds that contain nitrogen in their molecular structure. They are classified into two groups: purines and pyrimidines
The purine bases are adenine (A) and guanine (G). They are larger and contain more than one ring in their structure,.
The pyrimidines, cytosine (C), uracil (U) and thymine (T), are smaller and composed of a single ring.
3. One or more phosphate groups
A phosphate consists of a trivalent anion that contains one phosphorus atom and four oxygen atoms. Its molecular formula is expressed by 
.
Answer:
True:
"Stepping stones" are a type of corridor.
Explanation:
True, three types of the corridor can connect habitat clusters. The first one is called linear corridor and alludes to the line because it is a line. The second type of corridor is the landscape corridor which is a link of big sets of the material linked one to the other without a geometrical figure but creating a firm path. And finally, stepping stones corridors are composed of separated step stones that always keep distance one from the other.
I'm thinking the brain. The brain produces hormones and chemicals that tell the body to grow. And you also need to think a lot when trying to survive, which is when the brain comes in handy.
