Botany and Plant Science

Sporangia are present at adaxial surface of leaves in lycophytes.

A cluster of sporangia that has become fused in development is called a synangium. This structure is most prominent in Psilotum and Marattiaceae.

Sporophyte is diploid and gametophyte is haploid in alternation of generation.

Each microsporangium is lined with a nutritive tissue layer called the tapetum and initially contains diploid pollen mother cells.

Compound umbel is where the peduncle is branched from the tip of each branch a luster of flowers is produced in an umbellate manner called a compound umbel. Example: Coriander, carrot.

Within the megagametophyte one of the two sperms unites with the egg, forming a zygote, and the second sperm enters the central cell forming the endosperm mother cell, which completes the double fertilization process.

A small bract is called a bracteole or bractlet. Technically this is any bract that arises on a pedicel instead of subtending it as in Adhantoda. Bracts that appear in a whorl subtending an inflorescence are collectively called an involucre. An involucre is a common feature beneath the inflorescences of many Apiaceae, Asteraceae, Dipsacaceae and Polygonaceae.

Spike inflorescence has a long peduncle which bears a number of sessile flowers in acropetal succession. Example: Amaranthus.

Presence of multicapellary, syncarpous and multilocular gynoecium. The ovules are borne all over the inner surface of the ovary. Superficial placentation is also known as the laminar placentation. This type of placentation is observed in Nymphaeceae and Butomaceae.

Anther is that part of the stamen where pollen grain is produced.

The leaf of bryophyllum has notches on the margin. 

Ebractiate is the correct botanical term for a flower that lacks bracts (modified leaves associated with reproduction). The prefix 'e-' means 'without' in botanical terminology. Bracteate flowers have bracts, while heteromerous refers to flowers with different numbers of parts in each whorl.

Roots are positively geotropic (grow downward with gravity) and endogenous in origin (arise from pericycle). They lack nodes and internodes. Roots are negatively phototropic (grow away from light), not positively phototropic, which is why they grow deeper into soil rather than toward light sources.

Suckers originate from axillary buds located at nodes, which can develop into new aerial shoots that emerge from the base of the plant. They are lateral branches, not arising from terminal buds or stem tips. While they do arise from nodes, the most specific answer is axillary bud since that's the meristematic tissue that actually gives rise to the sucker.

Roots lack axillary buds, which are characteristic of stems. Roots have no nodes or internodes, no leaves, and no buds - these are stem features. Root hairs are present in the zone of maturation for water absorption. The absence of axillary buds is a key feature distinguishing roots from stems.