Root Systems in Plants

1.The conical fleshy tap root resembles a cone, that is, the thickest towards base and gradually tapering towards the apex, e.g., Carrot (Daucus carota)
2.The fusiform fleshy root is like a spindle, that is, thickest roughly in the middle and narrow towards both its base and apex, e.g., Radish (Raphanus sativus).
3.The napiform fleshy root is very thick at the base and is almost spherical. It suddenly thins out towards the apex (top-like), e.g., Turnip (Brassica rapa )
4.The tuberous roots are those thickened tap roots which do not assume any definite form, e.g., Mirabilis jalapa (Four O’ Clock).
So, the correct option is A. (A - 1, B - 4, C - 2, D - 3)

Answer is option B i.e. "Heritiera fomes and Ceriops roxburghiana"
Pneumatophores (breathing roots) are modification of root that assist in respiration whenever there is water lodging near root. They are found in halophytes (plants which grow in saline conditions) and mangroves. In mangrove families like Heritiera fomes and Ceriops roxburghiana, pnematophores acts as an organ of gaseous exchange.

Partial parasitic plants have chlorophyll which helps them to produce organic substances they require. They depend on the host for water and minerals, sometimes few chemical substances required for their growth. So, the correct option is B. ( Takes both water and nutrients from host plant )

Soybean and many other legumes fix atmospheric nitrogen into ureides (such as allantoin and allantoic acid) within the root nodules. These fixed nitrogen compounds are then exported to the shoot via the xylem vessels.

Lateral roots arise endogenously from the pericycle layer within the root, not exogenously. Therefore, the statement claiming lateral roots are exogenous in origin is incorrect, making it the right choice for the question asking for incorrect statements.

Groundnut, Bean and Alfalfa, all the three are legumes and thus the members of the family Leguminosae.

A haustoria is a root-like structure or a structure that grows into or around another structure to absorb water or nutrients. The root of a parasitic plant that penetrates the host's tissue and draws nutrients from it.

Symbiosis is a type of association of dissimilar organisms of their mutual advantage, e.g., association of nitrogen-fixing bacteria (nodule bacteria) with leguminous roots. The bacteria, inhabiting nodules on roots manufacture compounds from the nitrogen of the air, which becomes available to the plant. From the plant, bacteria obtain carbohydrates and other food materials.

Fungi are also known to form symbiotic relationship with plants (mycorrhiza). Many members of genus glomus forms mycorrhiza.

Bacteroid : Symbiotic bacteria Rhizobium leguminosarum in leguminous plants e.g., gram, pea etc. in their roots nodules produce Leg haemoglobin  this whole Bacteria + Leg haemoglobin + Polyploide  cells of roots is called as bacteroid. 

Nitrogen fixing bacteria are found in the root nodules of leguminous plants. Pea plant being a legume such bacteria would be found in its roots.

Pneumatophores are specialized respiratory roots found in mangroves like Sonneratia, and Banyan trees exhibit adventitious roots (prop roots). Statement (a) is wrong because root hairs arise from the maturation zone, not the elongation zone.

The swollen edible portion of a radish taproot is formed by the fusion of the true primary root and the hypocotyl, which is the embryonic stem region below the cotyledons.

Dalbergia is the fast-growing, hardy and surface feeder tap root. They are having a long taproot and numerous surface roots as well. In surface feeders, the taproot does not grow or develop to a great extent.

The cymose or surface feeder tap root systems of some annual plants are consisting of thin fibrous roots. Therefore, also called a fibrous tap root system.

The correct option is A.

Modified adventitious roots, which become green colour and perform photosynthesis. These are called as assimilatory roots, for example, Taeniophyllum, Trapa, Tinospora cordifolia. Tinospora is having climbing photosynthetic roots and is aerial. These are like the green hanging threads developing from the nodes during the rainy seasons.

The correct answers are A and B both. 

Allelopathy is a phenomenon associated with plants, in which one plant produce some chemical substances, which inhibits the growth of other plant species. While, in ammensalism, one species suffer and other remain unaffected.

Nodulation in legumes requires several minerals, but sulphur and potassium are critical for the development of nodules and the synthesis of nitrogenase enzymes.

Mycorrhizal fungi form a physical mantle or network around the roots, which acts as a physical barrier against soil-borne pathogens, in addition to aiding in nutrient uptake.

The incorrect match is: 

Secondary growth is the increase in the girth of stem and roots of plant. It occurs by cell divisions in two lateral meristems that are vascular cambium and cork cambium.

Velamen is the thick layer of dead cells that covers the aerial roots of certain orchids and aroids and absorbs moisture from the surroundings. Vanda is an example of a genus having velamen in their roots from orchid family.