Question

Which of the following is not functionally analogous with others in the group?
A. Archegonium
B. Oogonium
C. Antheridium
D. Ovule

Answer 1

All the above-mentioned organs are the reproductive organs of the different classes of the plant kingdom. The analogy here means having similar types of functions and the organs responsible for the production of spores (asexual reproduction) or production of gametes (sexual reproduction) are known as the reproductive organ. Another mode of reproduction is seen in plants is the vegetative mode of reproduction.

Complete answer:
Antheridium is a haploid structure or organ producing and containing male gametes seen in species of mosses, ferns, liverworts, and bryophytes, the plural form of antheridia and structure containing one or more than one antheridia are known as androecium, and it is the odd one in respect to the other options, hence the option C is the correct answer.

Additional Information:
Archegonium is the female reproductive part located at the tips of the main shoots of mosses under gametophytic life-cycle and also in the gametophytic phase of the bryophytes and are analogous to organs mentioned in other options hence option A is incorrect.
Oogonium (a small diploid cell) upon maturation forms a primordial follicle in a female fetus or female gametangium(organ or cells which produces gametes) of certain thallophytes including fungi lichens algae and sometimes bryophyte, it is analogous to the other option hence the option B is incorrect.
The ovule is a structure containing female reproductive cells and forms seed after the fertilization, mainly located in the flowering part inside the gynoecium, hence is analogous to the other organs in the option hence option D is incorrect.

Note:
Sexual reproduction in algae can occur by isogamy (union of two similar gametes), anisogamy (union of two dissimilar gametes), or by oogamy(union of motile male gamete and non-motile female gamete) and vegetative reproduction occurs through fragmentation. The life cycle of mosses can be haplontic (Chlamydomonas), diplontic (Codium), or diplobiontic (Laminaria , Ulva).