Question

Archegonium is absent in
A. Bryophyta
B. Pteridophyta
C. Thallophyta
D. Gymnosperms

Answer 1

Hint: An archegonium is defined as a multicellular structure or an organ of the gametophyte phase of some plants, producing and having the ovum/ female gamete. Simultaneously, the male organ is termed as antheridium. The archegonium consists of a long neck canal (or venter) and has a swollen base.

Complete answer:
You should know that, In bryophytes and other cryptogams, the sperm approach the archegonium by swimming in water films. On the other hand in Pinophyta and Angiosperms the pollen is delivered by wind as well as by animal vectors and the sperm are delivered through a pollen tube.
Pteridophytes differ from bryophytes by the fact, the sporophyte is branched and generally much bigger and more conspicuous, and from seed plants in that both generations are free-living and independent. The sexuality of pteridophyta gametophytes is divided as:
Dioicous: where each individual gametophyte may be male ( which produce antheridia and hence sperm) or may be female (producing archegonia and therefore egg cells).
Monoicous: a condition when each individual gametophyte makes both antheridia and archegonia and can act as both as a male and as a female.
Protandrous: the antheridia mature early the archegonia (male first, followed then female).
Protogynous: the archegonia mature earlier than the antheridia (female first, followed by then male).
In case of Gymnosperms- they have an archegonium which is made after pollination inside of female conifer cones /mega strobili.
Thallophyta is understood as a division of the plant kingdom having primitive forms of plant life which have a simple plant body. They include unicellular to large algae, fungi, lichens. The first ten phyla are known as thallophytes. They are very simple plants which do not have roots, stems or leaves. They don’t have archegonium.

Therefore, the correct answer is option C.

Additional information:
The female sex organ in non-flowering plants is referred as the archegonium. The archegonia are its plural form. The male sex organ in non-flowering plants is termed as an antheridium. A gametophyte is classified as the haploid gamete making form of a plant whereas a sporophyte is the spore making form of the plant.

Note:
Note that, the male and female sex organs named as the antheridia and the archegonia respectively, are made on the gametophytic plants. Haploid sperm are given or released from the antheridia and when a haploid sperm comes to a haploid egg in an archegonium the egg is then fertilized to make a diploid cell.