The first step in acquiring scientific knowledge is often:
Observation
Answer:
<u><em>DNA is made of repeating units called nucleotides.</em></u>
Explanation:
DNA can be described as a double helix molecule made up of long polymer chains of nucleotides. The nucleotides which are present in a DNA are:
Adenine (A)
Guanine (G)
Cytosine (C)
Thymine (T)
The hydrogen bonds which occur in the pairing of nucleotides makes the double helix structure of DNA.
Adenine forms hydrogen bonds with Thymine.
Guanine forms hydrogen bonds with Cytosine.
The backbone of the DNA is made up of sugars and phosphates
It is Genome. Have a good day.
Allopatric speciation is said to occur when two groups of organisms are separated by a physical or geographical barrier. Examples of such barriers are ocean, mountain range, rivers, etc. A good example of allopatric speciation is Galapagos finch. Different species of this bird can be found in different islands at Galapos, which is located at Pacific Ocean off South America. The ocean is barrier that isolate the species from one another.