Question

Sex first originated in
(a) Protistans
(b) Simple algae
(c) Angiosperms
(d) Both (a) and (b)

Answer 1

They first originated in a primitive era. They are simple and undifferentiated organisms without any specialized groups for performing various functions. They are usually found in ponds, lakes, rivers, etc.

Complete answer
organisms. The nucleus present in them is prominent and is surrounded and covered by a nuclear membrane. The nucleus of protists is composed of histone proteins found in the DNA molecule and the cell consists of the cell cytoplasm along with the various cell organelles. For the process of reproduction, they produce spores that result in the formation of the fruiting bodies. For certain stages, during their life cycle, the cells of these are motile and then become immobile for the rest of the life cycle. They undergo both sexual and asexual reproduction. Examples include paramecium, amoeba, euglena, etc.
Algae are photosynthetic. They are found to be either unicellular or may be multicellular organisms. They lack a well-defined body, instead, they have a thallus. In the case of algae, their body is thallus-like lacking differentiation of body parts thus the structures like stems, roots, and leaves are absent in them. They are mostly aquatic in habitat and undergo both sexual and asexual type of reproduction.
An angiosperm is a higher plant, having a well-differentiated plant body that consists of various plant parts and for the process of reproduction, they produce the flowers and the seeds. The reproduction results in the production of both the male and the female gametes that after fusion will result in the process of fertilization. The angiosperms have fully covered ovules that mature in proper protection and are also covered.

So, the correct answer is ‘Both (a) and (b)’.

Note:
The origination of sex occurs due to the asexual and rapid multiplication of the protistans and algae during favorable conditions but at the onset of unfavorable conditions gametes are produced resulting in their fusion and formation of zygote. The zygote germinates during unfavorable conditions and thus this cycle is repeated.