Difference Between Haploid and Diploid

The key difference between haploid and diploid is that haploid is the state of having half the usual number of chromosomes while diploid is the state of having the usual number of chromosomes in the genome of a cell.

The cell cycle is the series of events that occur from one cell division to the next cell division. Prokaryotic cell cycle involves 3 stages. Cell growth is the first step, where the cell doubles in its size. Nuclear division is the next step where the nuclear material divides into two by simple division. The final step is cell division, in which the cytoplasm divides and forms two daughter cells. The eukaryotic cell cycle has 5 phases: G1, S, G2, M and C. The first three phases G1, S, and G2 come under interphase. The cell growth and synthesis of cellular materials take place during interphase. M stands for nuclear division while C stands for cytokinesis. Cytokinesis is the actual process that produces daughter cells. Ploidy level can be different in the resulting cells. Thus, they can be haploid (n) or diploid (2n) in eukaryotes.

CONTENTS

1. Overview and Key Difference
2. What is Haploid 
3. What is Diploid
4. Similarities Between Haploid and Diploid
5. Side by Side Comparison – Haploid vs Diploid in Tabular Form
6. Summary

What is Haploid?

A haploid cell contains only one set of chromosomes. That means; it contains half the usual number of chromosomes in a cell. Meiosis is the type of cell division that produces haploid cells. During meiosis, the daughter cells receive only half of the total chromosomes in a diploid cell. Similar to mitosis, DNA replication in meiosis also takes place in the parent cell during the interphase. After this, two cycles of nuclear divisions and cell divisions take place. After the entire process, one diploid cell gives rise to four haploid cells.

Haploid cells are very important for sexual reproduction. During fertilization, the two nuclei of the two gametes fuse with each other. Since each gamete has only one set of chromosomes, the resulting zygote will have only two sets of chromosomes. Due to this, the zygote becomes diploid. If the gametes were not haploid cells, the resulting zygote would contain four sets of chromosomes.

What is Diploid?

A diploid cell contains two sets of chromosomes: one is maternal while the other is paternal. Mitosis is the type of cell division that produces diploid cells. During mitosis, the parent nucleus divides into two daughter nuclei, which are genetically identical. Hence, each daughter nucleus receives the same number of chromosomes as the parent nucleus. After the division of the nucleus, the entire cell divides. Since this process needs to take place without any error, all the chromosomes replicate during the interphase. Then the sister chromatids separate into each pole of the cell during mitosis.

Diploid cells play a very important role in the genetic stability of diploid organisms. Especially, these daughter cells are genetically identical to the parent cell. In addition, they carry the same number of chromosomes as the parent cell. It is the way how they ensure the genetic stability of populations during the inheritance. The growth of the body takes place due to the continuous increase in the number of diploid cells. Thus, this is the basis of growth in all multicellular organisms. Furthermore, cells continuously die, and they need to be replaced. And, it can be done only by diploid cells. Also, some animals regenerate their body parts. It too is possible only by the formation of many diploid cells.

What are the Similarities Between Haploid and Diploid?

• Haploid and diploid are two states that describe the number of chromosomes in a cell.
• The formation of haploid and diploid cells takes place via cell division.
• Also, both types of cells are important to organisms for their survival and existence.

What is the Difference Between Haploid and Diploid?

Haploid and diploid are two ploidy levels seen in cells. Haploid cells are the cells that contain only one set of chromosomes, while diploid cells are the cells that contain two sets of chromosomes. So, this is the key difference between haploid and diploid. Furthermore, one other significant difference between haploid and diploid is their formation. Formation of haploid cells occurs through meiosis, while the formation of diploid cells occurs through mitosis.

Moreover, a further difference between haploid and diploid is that the haploid cells have only a half the number of chromosomes as the parent cell, while diploid cells have the same number of chromosomes as the parent cell. In addition, haploid cells are not genetically identical to the parent cell, while diploid cells are genetically identical to the parent cell. Besides, one more difference between haploid and diploid is the importance of each type of cell. Haploid cells are important in sexual reproduction, while diploid cells are important in growth, asexual reproduction and genetic stability.

Summary – Haploid vs Diploid

A haploid cell has half the usual number of chromosomes. Thus, it contains ‘n’ number of chromosomes. A diploid cell has the usual number of chromosomes. Thus, it contains ‘2n’ number of chromosomes. So, this is the key difference between haploid and diploid. Furthermore, haploid cells are important in sexual reproduction, while diploid cells are important in growth, asexual reproduction and genetic stability. Thus, this is the summary of the difference between haploid and diploid.

Reference:

1. “haploid” Nature News, Nature Publishing Group, Available here.
2. “Ploidy.” Wikipedia, Wikimedia Foundation, 27 Apr. 2019, Available here.

Image Courtesy:

1. “Haploid vs diploid” By Ehamberg – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Mitosis diagram” By Marek Kultys – Own work(own work by uploader).Źródło (source) (CC BY-SA 3.0) via Commons Wikimedia