Botany and Plant Science

Grafting is a technique whereby tissues from one plant are inserted into those of another so that the two sets of vascular tissues may join together.
The plant that is selected for its roots is called the stock while the other plant, selected for its stems, leaves, flowers or fruits is called the scion
Thus, the correct answer is option (B), 'Scion'.

In Passiflora, the tendrils are modified axillary buds that help the plant climb.

In leaf and stem cuttings, the explant is taken from the apical portion of leaf or stem as it has a meristematic cell which has active nucleus and cytoplasm. The meristematic cell divides rapidly when cultured on nutrient media and provides virus-free plant. When the apical portion of the leaf or stem culture is sown, it is sown vertically with morphological apical end upwards to ensure maximum growth by keeping the meristematic cell at the top.

The development of roots on a stem while the stem is still attached to the parent plant is called layering. The heavy and closely branched stems of trees like fruit producing trees can be layered by the method of mound layering. The plants are cut near the soil level when they are not growing. Dormant buds on stem produce new shoots in spring. The new shoots are soft basal branches of the stem. When these shoots are covered with mound of soil they grow roots at the bases of shoots.

Grafting is a horticulture technique where the living detached portion of the plant is used to regenerate the growth. One plant is selected for its roots and this is called the stock or rootstock. The other plant is selected for its stems, leaves, flowers, or fruits and is called the scion. The joining of scion and stalk is known as inosculation. 

(A)An apical bud is the one that is at the end of the shoot.

Stems are characterized by the presence of nodes and internodes, whereas roots lack these structures.

Callus is unorganized actively dividing mass of cells maintained in culture. It has meristematic cell which has ample amount of cytoplasm to trigger cell division. It is an undifferentiated mass of cell which differentiates when treated with the growth hormones to promote cell division, differentiation and morphogenesis. It heals the injury in the cell as callus has meristematic cell which replaces the worn out and damaged cell by rapid cell division and it can also replace damage tissue developed in the region of wound.

Steward et al. (1958) used phloem tissue from the secondary root of a carrot to demonstrate cellular totipotency.

Stigma, style, and ovary are parts of the female reproductive organ (pistil/carpel) of a flower. Pollen is the male gametophyte.

In an amphiphloic siphonostele, the phloem is found on both the outer and inner sides of the xylem. This is a specific type of vascular arrangement in certain plants.

Mucor mucedo reproduces asexually. When erect hyphal sporangiophores are formed. The tip of the sporangiophore swells to form a globose sporangium that contains uninucleate, haploid sporangiospores. 

Mucor is a microbial genus of molds commonly found in soil, digestive systems, plant surfaces etc. During sexual reproduction, compatible strains form short, specialized hyphae called gametangia. At the point where two gametangia fuse, a thick-walled, spherical zygosporangium develops. The zygosporangium typically contains a single zygospore.

Roots do not show the distinction of nodes and internodes because the meristematic part of the roots is at the tip, but not in the middle showing differentiation. Roots have endogenous primary secondary and tertiary roots and rootlets.

A root cap is a protective covering over the tip of the root. Pandanus is known to have multiple roots because it has multiple prop roots covered with root caps.