Botany and Plant Science

• Mangroves are marshy areas found in tropical deltas and saline ponds near sea shores. An important characteristic of mangrove plants is vivipary or seed germination while fruit is attached to plant. The seedling grows sufficiently before it falls into the saline marsh. Only the radicle part passes into mud or water while the plumule part remains above the surface of water, e.g., Rhizophora, Aegiceras, Ceriops.
• Heterospory is shown by pteridophytes and seeded plants which means the production of different kinds of spores; microspores and megaspores. 
• Parthenocarpy is the process of formation of fruit without fertilization.
• Apospory is the formation of gametophyte directly from sporophyte without meiosis.

• A mangrove is a shrub or small tree that grows in coastal saline or brackish water. They protect shorelines from damaging storm and hurricane winds, waves, and floods.
• mangroves disperse propagules via water with varying degrees of vivipary or embryonic development while the propagule is attached to the parent tree. Hence mangroves exhibit vivipary.
  
• Pneumatophores are specialized root structures that grow out from the water surface and facilitate the aeration necessary for root respiration in hydrophytic trees. For example, mangroves. 
• Pneumatophores are the supporting roots for mangroves.
• Hence Vivipary, Pneumatophores, and Supporting roots are the characteristics of mangroves.
• So, the correct answer is 'All the above'.

The soil in coastal region is poorly aerated and it contains very small percentage of oxygen, because of waterlogging. Under such conditions, the roots of halophytes do not get sufficient aeration. In order to compensate this lack of soil aeration, the hydro-halophytes develop special type of negatively geotropic roots, called as pneumatophores or breathing roots. The pneumatophores usually develop from the underground roots and project in the air well above the surface of mud and water. They appear as peg-like structures. The tips of these respiratory roots may be pointed. They possess numerous lenticels or pneumathodes on their surface and prominent aerenchyma enclosing large air cavities internally. The gaseous exchange takes place in these roots through the lenticels.

A number of halophyte plants possess small negatively geotropic vertical roots, called as pneumatophores. Pneumatophores have lenticels for gaseous exchange. They are connected with internal aerenchymatous tissue.

A rhizophore is a specialized organ found in plants like Selaginella that acts as an intermediate structure, exhibiting characteristics of both roots and stems.

Mangroves possess various root adaptations to survive in waterlogged, anaerobic, and saline soils, including pneumatophores for gas exchange, and stilt/prop roots for structural support.

Viviparity (seeds germinating while still attached to the parent) and pneumatophores (aerial roots for breathing) are classic adaptations of mangrove species, which are halophytes.

A. Apospory -include formation of Diploid gametophytes, without meiosis and spores, from vegetative cells of the sporophyte. for example - mosses and ferns.
B. Heterospory- is fornation of spores of two different sizes i.e smaller of these, the microspore, is male and the larger megaspore is female by the sporophytes of land plants. for example -pteridophytes -Selaginella and Salvinia.
C. Parthenocarpy is the development of a fruit without fertilization, which makes the fruit seedless, for example- Pineapple, banana.

Pneumatophores are specialized aerial roots that grow upwards to facilitate gas exchange in the oxygen-poor, waterlogged soils typical of halophytic environments. Velamen is found in epiphytes, lenticels in stems, and hydathodes in leaves for guttation.

Vivipary is a condition where seeds germinate while still attached to the parent plant. This is a characteristic adaptation of mangroves like Rhizophora to survive in unstable, saline environments.

Pneumatophores are respiratory roots that emerge from the soil to obtain oxygen in anaerobic conditions. They are a defining feature of mangroves, which are halophytic plants.

A bisexual flower (or “perfect”) has both stamens and carpels, and a unisexual flower (or “imperfect”) lacks stamens is called staminate.

Balanophora is a well known example of a parasitic plant that attaches to the roots of host plants to obtain nutrients, making it a root parasite.

• Pitcher plants are several different carnivorous plants which have modified leaves (act as a pitcher) which are known as pitfall traps—a prey-trapping mechanism featuring a deep cavity filled with digestive liquid. 
• These plants trap harmful insects and kill them with the help of digestive fluid.

Cuscuta (Dodder) plant is an obligate or total stem parasite. It lacks chlorophyll and has no connection with the soil after the seeding stage. Therefore it is totally dependent on the host for organic food materials and supply of water and minerals salts. The parasitic plant pierces the stem and sucks the nutrients from the host plant.