Optionals IAS Mains Botany: Questions 148 - 157 of 511

Dicot System

In most of the dicot stems after differentiation of primary tissue they increase in breadth by secondary growth. This growth is due to the activity of lateral Meristems

• The vascular cambium and phellogen or cork cambium
• The vascular cambium differentiate into the stelar is and secondary xylem and secondary phloem. The phellogen on the oth…

Pollen Grains (Male Gametophyte Mother Cell) or Microspore

• During gametogenesis the nucleus of pollen grain divides into a small lenticular generative cell and large vegetative cell.
• The generator cell again divides and to form two male gametes and hence Pollen Grain is called the male gametophyte of plant.

Stratification of Pollen Grain

• Pollen Grain h…

Contractile Vacuoles in Euglena

• Contractile vacuole is vacuole type which expands and contract according to water availability inside the sell.
• Its function is to regulate water concentration inside the cell.
• A single cell organism lacking cell wall have contractile type of vacuole, which expand and contract itself to remove extra water from organism.
• …

Isotype and Syntype

• Plant name publication and designation of type of specimens follows the rules developed at the international botanical congress current rules.
• International code of nomenclature for algae, fungi, and plants require that a single type specimen be designated at the time of publication (holotype) .
• Duplicates of the specimen with the …

Micropropagation Technique

• The techniques of Micropropagation has been successful in achieving our goals upto very long extent some of the examples are that Micropropagation techniques are now after preferred to conventional practices of a sexual propagation because of the given reasons not only for commercial point of you but also with regard to cr…

Types of plant found in Palaeozoic ERA and Cenozoic Era

Palaeozoic Era

• The vegetation is both aquatic and land plants.
• Aquatic plants like Nematothallus and prototaxites showed resemblance with thallophytes. The first Fossil of land plants were found in the Silurian and Devonian period of this era.
• Manograptus, sporogonites, zosterophyllum, cooksonia, …

Megasporogenesis and Megagametogenesis

• Megasporogenesis and mega gametogenesis is a very important process in angiosperms.
• The ovule develops as multicellular Placenta outgrowth. In further development nucleus and one or two integuments are formed.
• Hypodermal cell of nucleus become differentiated from the other and that՚s call archesporial.
• Archesporal…

Molecular Basis of Plant-Pathogen Interaction

• During the contact between plants and pathogen a particular chain of events happen in the plant,
• The plant is provided by receptor that interacts with bacterial protein; as a result quick protective reaction is being developed.
• The protein of pathogenic organism are virulent for the given plant genotype.
• Th…

Transfusion Tissue

Transfusion tissue is the tissue that is found around the vascular bundle of gymnosperm leaves.

Structure and Location

• There are group of bracket like cells on the lateral side of the vascular xylem in the mid represent the cells are small and broad pits and have reticulate thickening on there was there called transfusion tissue.
• In …