Question

Consider the following four statements and find out which of them is wrong.
A. The sporophyte in liverworts is more elaborate than that in mosses.
B. Salvinia is heterosporous.
C. The life-cycle of all seed-bearing plants is diplontic.
D. In Pinus , male and female cones are borne on different trees.
I. Statements (A) and (C)
II. Statements (A) and (D)
III. Statements (B) and (C)
IV. Statements (A) and (B)

Answer 1

Sporophytes are the capsulated structures in primitive plants like bryophytes. These enclosed spores that are released and then germinate to form new plants. Salvinia is a water fern and produces spores of different sizes called heterosporous. The seed-bearing plants are those that germinate through seeds.

Complete step by step answer: Let us go through each statement and understand the characteristics of the given species. Also, we will know the meaning of various terms.
-Statement A is that the sporophyte in liverworts is more elaborate than that in mosses. In the Liverwort sporophytes, there is always the presence of a spore-containing capsule. This capsule can be spherical or cylindrical. The capsule turns black and splits open to release spores when the Liverwort matures. But in addition to spores, there are elaters present in capsules. Elaters are spiral microscopic structures that help in spore dispersal. On the other hand, if we talk about mosses, they do not contain elators. Their capsule consists of spores purely. Also, their capsule opens by true mouth structure. So, we can conclude that mosses have more developed sporophytes than Liverwort. Thus, this statement is wrong.
-Statement B says that Salvinia is heterosporous. This means that they produce spores of different sizes. It is true as it relates to the water ferns like Azolla that comes under Salviniales. Thus, like all other ferns, Salvinia too produces heterosporous spores. Hence, this statement is right.
-Statement C is that the life-cycle of all seed-bearing plants is diplontic. The term diplontic life-cycle means that the seed-bearing plants will have a major part of their life as in diploid or form. It is true as the gametes of seed-bearing plants are haploid having half the set of chromosomes. So, when they fuse to form a zygote that results in a seed, it results in diploidy of attainment of a full set of chromosomes. Thus, this seed when germinates undergoes a diplontic life-cycle except for gametes.
-Statement D says that in pinus, male and female cones are borne on different trees. It is known that pinus produces heterosporous. This means that they produce two types of spores called micro and megaspores. These represent male and female spores respectively. Therefore, pines are monoecious meaning that male and female cones are on the same plant. So, this statement is wrong.
Hence, the correct answer is Option II

Note: The biological terms hold their meanings in them. Once we split the terms, we can understand its meaning easily. Liverworts and mosses both come under bryophytes. The diplontic life cycle means having a diploid set of chromosomes. Pinus is a gymnosperm that has male and female parts on the same plant.