What is the Difference Between Antheridium and Archegonium

The main difference between antheridium and archegonium is that antheridium is the haploid structure producing male gametes in cryptogams such as ferns and bryophytes, whereas archegonium is the multicellular structure producing female gametes in both cryptogams and gymnosperms. Furthermore, antheridium is a club-shaped structure born on a short, multicellular stalk while archegonium has a neck, venter, and a swollen base. In addition to these, androecium resembles the antheridium in flowering plants while gynoecium resembles the archegonium. 

Antheridium and archegonium are the two types of reproductive organs in cryptogams. Generally, cryptogams include pteridophytes, bryophytes, and thallophytes. They undergo a ‘hidden reproduction’ through the production of spores, without flowers or seeds. 

Key Areas Covered 

1. What is Antheridium
     – Definition, Structure, Function
2. What is Archegonium
     – Definition, Structure, Function
3. What are the Similarities Between Antheridium and Archegonium
     – Outline of Common Features
4. What is the Difference Between Antheridium and Archegonium
     – Comparison of Key Differences

Key Terms 

Archegonium, Antheridium, Cryptogams, Gametes, Sex Organs

What is Antheridium 

Antheridium is the male sex organ, which produces male gametes in cryptogams. Generally, it is a haploid structure whose function is to produce male gametes called antherozoids or sperms. Furthermore, androecium refers to the structure containing one of more antheridia. It also refers to a collection of stamens in flowering plants. However, the gametophyte of ferns, bryophytes, and algae contains antheridia. Antheridia are reduced to form a pollen grain in both angiosperms and gymnosperms, being a single generative cell. 

Figure 1: Antheridia

Furthermore, antheridium is a club-shaped structure with two components: sterile cells and the spermatogenous tissue. Basically, the sterile cells serve as a protective jacket, forming a central support structure. Meanwhile, the spermatogenous tissue undergoes mitosis to produce spermatids. The male gametes or sperms are motile in cryptogams, and therefore, they require water for undergoing fertilization. 

What is Archegonium 

Archegonium is the female sex organ, which produces female gametes mainly in cryptogams. It is responsible for the production of female gametes: egg cells or ova. Generally, archegonia occur on the thallus of the gametophyte in cryptogams. Typically, the motile male gametes swim through the water films to enter into the archegonia. In gymnosperms, archegonia are much-reduced structures embedded in megagametophytes. However, archegonia in both gymnosperms and cryptograms produce a single egg cell.

Figure 2: Archegonium

Moreover, archegonium is a flask-shaped structure. It also contains two parts: the venter and a swollen base. Normally, the venter or the long neck encloses both the egg cell and the venter canal cells. Also, it is composed of six vertical rows of neck cells, enclosing the neck canal cell. In gymnosperms, the diploid cells of the megasporangium or the nucellus surround the ovule inside which female germ cell occurs. Especially, archegonium forms following pollination inside megastrobili in gymnosperms. 

Similarities Between Antheridium and Archegonium 

• Antheridium and archegonium are the two types of reproductive structures of cryptogams. 
• Pteridophytes, bryophytes, and thallophytes produce these types of reproductive structures. 
• They undergo a type of ‘hidden reproduction’. 
• They take part in the production of spores in the sexual reproduction of cryptogams. 
• Generally, the germination of haploid spores gives rise to the gametophyte, which produces these reproductive structures. Therefore, both antheridium and archegonium are haploid. 
• Their main function is to produce gametes. 
• Ultimately, the fertilization of haploid gametes gives rise to the diploid zygote, which in turn develops into the sporophyte. Significantly, the sporophyte undergoes meiosis inside the sporangium to produce the haploid spores. 

Difference Between Antheridium and Archegonium 

Definition 

Antheridium refers to the types of male reproductive organs in cryptogams, while archegonium refers to the type of female reproductive organs in cryptogams and within which an embryo will develop.  

Morphology  

While antheridium is a club-shaped structure born on a short multicellular stalk, archegonium is a flask-shaped structure raised on a short stalk. 

Structure 

Antheridium has a sterile jacket, enclosing a large number of cubic spermazoical sperm mother cells, while the two parts of the archegonium are the venter, enclosing egg cells and venter canal cells and a swollen base. 

Type of Gametes 

Moreover, antheridium produces male gametes which are motile while archegonium produces female gametes which are non-motile. 

Number of Gametes 

Antheridium produces a large number of male gametes while archegonium produces a single female gamete.  

In Gymnosperms 

The role of antheridia is filled by the pollen grain in gymnosperms while the archegonium of gymnosperms is a much-reduced structure embedded in the megagametophyte. 

In Flowering Plants 

Androecium resembles the antheridium in flowering plants while gynoecium resembles the archegonium in flowering plants. 

Conclusion 

Antheridium is the male sex organ in cryptograms, including ferns, bryophytes, and algae. Generally, it produces a large number of motile male gametes. Also, it has a club-shaped structure on a short stalk. In addition to these, a sterile jacket encloses the sperm mother cells in the antheridium. In comparison, archegonium is the female sex organ in cryptogams. Gymnosperms produce reduced archegonia. However, archegonium is responsible for the production of a single, non-motile egg cell, enclosed by the venter. Therefore, archegonium is a flask-shaped structure, containing a short stalk. The main difference between antheridium and archegonium is their structure and their production of gametes.   

References:

1. Baron, Adrianne. “Archegonium & Antheridium: Definition & Function.” Study.com, Study.com, Available Here.

Image Courtesy:

1. “Antheridia” By I, EncycloPetey (CC BY-SA 3.0) via Commons Wikimedia  
2. “Archegonium” By I, EncycloPetey (CC BY-SA 3.0) via Commons Wikimedia