NEET Practice Questions (MCQs) with Answers & Solutions

Roots in Cycas are of two types - normal and coralloid roots. Coralloid roots are irregular, negatively geotropic, dichotomously branched coral like roots which do not possess root hair and root caps. Coralloid roots have a symbiotic association with blue-green algae like Nostoc and Anabaena species.

Alginic acid (or algin or alginate) is an anionic polysaccaride distributed widely in the cell walls of many brown algae (Phaeophyceae). It is a phycocolloid which is obtained commercially from Laminaria, Macrocystis, Nereocystis, Fucus, Sargassum etc.

Genera like Selaginella and Salvinia which produce two kinds of spores, macro (large) and micro (small) spores, are known as heterosporous pteridophytes Lycopodium and Equisetum are homosporous pteridophytes. i.e., they produce only one type of spores.

Pteridophytes, may produce similar spores (homosporous) or dissimilar spores (heterosporous). Selaginella and Salvinia show heterospory.

Classical taxonomy is based on the morphological traits. It is also called alpha taxonomy or old systematics.

In bryophytes, zygote is the beginning of the sporophytic generation. Within venter of the archegonium, the zygote undergoes segmentation and develops without a resting period into a multicellular, undifferentiated structure called embryo. The embryo by further segmentation and differentiation finally develops into a full fledged sporophyte, called sporogonium.

All living species of Cycas are dioecious, i.e. male and female structures occur on separate plants. Male plant bears male strobilus or male cone, which is formed by the aggregation of microsporophylls. In female cone, the megasporophylls are loosely arranged.

Cycas is classifiied as gymnosperms as it has naked ovule. Becuse of naked ovule, all gymnosperms form naked seed which differentiate them from angiosperms. Fruit and motile sperms are the common characteristics of both gymnosperms and angiosperms. Pycnoxylic wood is found in Pinus.

In Marchantia elater mother cells give rise to elaters which helps in scattering the spore differentiated from the spore mother cells.

In Riccia and Funaria the elaters are not found. Elaters are small neutral cells in form of fibre in capsule.

RH Whittaker in year 1969 divided all organism into five kingdom these are

Monera → Kingdom of prokaryotes

Protista → Kingdom of unicellular eukaryotes

Fungi → Kingdom of unicellular decomposers

Plantae → Kingdom of multicellular producers

Animalia → Kingdom of multicellular consumers