Classification of organisms is based upon a number of physical and p.pdf
- 1. Classification of organisms is based upon a number of physical and physiological features. The structure and organization of reproductive organs remains in important feature usually used to distinguish organisms. Some of the features can be discussed as below: 1. Fruiting body: A very broad classification can be made on the basis whether the fruiting body is present or not. Presence of a fleshy or modified cover around the seed is a characteristic feature of angiosperms whereas a naked seed located directly above a vegetative structure of a plant is a feature of gymnosperms. 2. Spores sacs: Spore releasing sacs are characteristic features found on the lower scales of the leaf blades of lower and higher ferns. Their arrangement and mode of release determines the nature, frequency and ease of sexual reproduction in these lower plants. 3. Pollens: Higher plants, including both angiosperms and gymnosperms utilize pollen grains for sexual reproduction. The mode of transfer of pollen determines the geographical range of pollination in plants. Sulphur shower is a critical example for sexual reproduction in pines (gymnosperms) which distinguishes them from other trees. 4. Sporocarp: A sporocarp or a fruiting body is a bulging of the vegetative extension from the main structure of a lower fungi which contains a group of cells which either follow meiotic division or mitotic division and serve as the reproductive structures. Their growth and nature can be monitored microscopically and the fungus can be thus classified appropriately. Some algae also contain a unique localization and arrangement of haploid cells called spores which can be present in singles or doublets and thus represent a very unique discrimination from other organisms. These, these set of information provide an insight into usability of features of a reproductive structure for classification of organisms. Solution Classification of organisms is based upon a number of physical and physiological features. The structure and organization of reproductive organs remains in important feature usually used to distinguish organisms. Some of the features can be discussed as below: 1. Fruiting body: A very broad classification can be made on the basis whether the fruiting body is present or not. Presence of a fleshy or modified cover around the seed is a characteristic feature of angiosperms whereas a naked seed located directly above a vegetative structure of a plant is a feature of gymnosperms. 2. Spores sacs: Spore releasing sacs are characteristic features found on the lower scales of the leaf blades of lower and higher ferns. Their arrangement and mode of release determines the
- 2. nature, frequency and ease of sexual reproduction in these lower plants. 3. Pollens: Higher plants, including both angiosperms and gymnosperms utilize pollen grains for sexual reproduction. The mode of transfer of pollen determines the geographical range of pollination in plants. Sulphur shower is a critical example for sexual reproduction in pines (gymnosperms) which distinguishes them from other trees. 4. Sporocarp: A sporocarp or a fruiting body is a bulging of the vegetative extension from the main structure of a lower fungi which contains a group of cells which either follow meiotic division or mitotic division and serve as the reproductive structures. Their growth and nature can be monitored microscopically and the fungus can be thus classified appropriately. Some algae also contain a unique localization and arrangement of haploid cells called spores which can be present in singles or doublets and thus represent a very unique discrimination from other organisms. These, these set of information provide an insight into usability of features of a reproductive structure for classification of organisms.