Answer:
Because DNA molecules are extremely long.
Explanation:
DNA molecule is made up of only four types of nucleotides that are adenine, guanine, cytosine, and thymine. These four types of nucleotide encode all the information necessary for the formation and working of the entire organism because each DNA strand is as long as 2 meter which contains millions of base pairs.
The four nucleotides are arranged in the DNA strand with many different combinations which results in the formation of codons sequence that contains all the information about the cell. This long DNA is compressed several times to fit in the nucleus.
Plant Kingdom to species is 24,000 or more species are broken up into three groups/division: Mosses, Liverworts, and Hornworts.
Cell membranes protect and organize cells. All cells have an outer plasma membrane that regulates not only what enters the cell, but also how much of any given substance comes in. Unlike prokaryotes, eukaryotic cells also possess internal membranes that encase their organelles and control the exchange of essential cell components. Both types of membranes have a specialized structure that facilitates their gatekeeping function.
Organ is an organism that is a collection of tissues and it perform a specific functions.It is found in the higher biological systems like plants, animals, and human beings. While the organelle is a part of a cell that specialized units and capable of performing a specific function for the cell. It is a very small subunits inside a cell.