Plant Reproduction and Germination

Obturators are specialized structures that guide the pollen tube towards the micropyle during fertilization. They are typically outgrowths of the funicle or placenta in certain plant families.

 Recalcitrant seeds are those which get killed on reduction of moisture. Plants that produce recalcitrant seeds include avocado, mango, mangosteen, lychee, cocoa, rubber tree, some horticultural trees.

This is the correct answer. Fast changes occur over a short interval of time. 

This is the correct answer. Germination of a seed will create a plant and this is an irreversible change.

In an embryo, the hypocotyl is the region below the cotyledons, and the epicotyl (embryonic shoot) is the region above the attachment of the cotyledons.

The embryo is the rudimentary plant contained within a seed, which develops into a new plant upon germination.

The leaves present inside the seed and contain reserve food are called Cotyledonary leaves.

A samara is a dry, indehiscent fruit where the pericarp develops into a wing-like structure to aid in wind dispersal. Examples include maple and ash trees.

A capsule is a dry dehiscent fruit formed from two or more fused carpels, typically containing many seeds. It is a very common type of fruit in many flowering plants.

Wings are thin, flat membranous appendages on fruits and seeds that aid in wind dispersal. Examples include samara fruits. Hairs and light seeds/fruits are different dispersal mechanisms, and 'Censer mechanisms' appears to be a typo or nonsensical term.

Explosive mechanisms involve the rapid, forceful dehiscence of a fruit, which ejects seeds away from the parent plant. This is common in plants like touch-me-not (Impatiens).

When animals consume fleshy fruits, the seeds often pass through their digestive tracts unharmed and are deposited in new locations, facilitating dispersal.

Animals like squirrels often cache nuts in the ground for later consumption. If the animal forgets the location, the nuts may germinate, effectively dispersing the plant.

Mistletoe seeds are covered in a sticky substance called viscin, which allows them to adhere to the beaks or feet of birds, helping them spread to other trees.

Vernalization involves exposing seeds to low temperatures, typically in the range of 0 to 5 degrees Celsius, to promote flowering.