Tag: biology

The book 'Structure and Reproduction of the Algae' describing taxonomy of algae is written by Felix Eugen Fritsch FRS. He was a British biologist. He gave very comprehensive and authoritative account of classification of algae based on a variety of characters as pigmentation, stored food matter, habit, habitat and method of reproduction. 

X can be thallophytes which have an undifferentiated plant body, that is, in the form of an undivided thallus. Algae are thallophytes belonging to kingdom Plantae. Fungi belong to kingdom Fungi. Y can be pteridophytes which are seedless vascular plants and differentiated into true stern, leaves and roots. Bryophytes are simple land plants with no true roots. The plant body is thallose or foliose. Z can be angiosperms or gymnosperms since both of them have seeds. However, angiosperms have seeds covered by fruit whereas gymnosperms have naked seeds. So, the correct answer is option D. 

Bryophytes are the plants in which the life cycle has two phases gametophytic and sporophytic, alternating to each other. This phenomenon is called alternation of generation. Gametophytic phase is haploid, autotrophic, gametes(male and female) formative and responsible for the sexual reproduction. Sporophytic phase is the subsidiary phase which is diploid, heterotrophic and spore formative and responsible for the asexual reproduction. For example, Riccia, Funaria.

Kingdom Plantae includes all eukaryotic chlorophyllous autotrophic organisms. A few members are partially heterotrophic such as insectivorous plant or parasites. bladderwort and venus fly trap are examples of insectivorous plants and Cuscuta is a parasite. 

Chlorophyta is the green algae that contain the pigment chlorophyll A and chlorophyll b in the well-defined chloroplast. Plants are considered to have evolved from Chlorophyta because plants are green in color and they have chlorophyll A and chlorophyll b pigment just like the Chlorophyta family.

The tip of the leaf help in vegetative propagation in Adiantum caudatum. It is an evergreen, perennial fern producing fronds up to 60 cm tall from a shortly-creeping rhizome. It is also known as Maidenhair fern because of the shiny black rachis of the leaves. It has buds at the tip of the leaf which helps in vegetative propagation. The buds enter the ground when the leaf bends and touches the soil. There they develop into a new individual. Due to this phenomena, it is also known as walking fern.