<h2>
Answer</h2>
It is because of different arrangements of nucleotide bases.
<h2>
Explanation</h2>
There are only five types of nucleotide basis are present in the genetic material which makes up the all the genetic information of the individuals. These nucleotides are named as Adenine, Thymine, Guanine, Cytosine and Uracil. In all the living beings on the earth, these only five nucleotides are present which decides their behaviour and functions on the earth. These five bases have features to get any arrangements according to the situation. Their different arrangement at the heredity material makes the difference in all living beings regarding their behaviour.
Mouth, throat, small and large intestine
Answer:
B) Multicellular Simple gland
Explanation:
Exocrine Glands:Glands that secrete their products onto the apical(or epithelia) surface directly or via epithelial ducts or tubes that are connected to the apical surface. These Exocrine glands are composed of highly specialized epithelial cells..
Exocrine glands can either be branched or Unbranched based on the arrangement.
*Multicellular simple glands*:Glands that have an *unbranched duct* into which cells secrete. Each secretory portion empties separately on an epithelial surface.