In black pepper and beet, a part of the nucellus remains unused. What is this persistent nucellus called?

The entry of oxygen and water into the seed during germination is facilitated by . . . . . . .

What do the following parts of a flower develop into after fertilisation? $(a)$ Ovary $(b)$ Ovules.

. . . . . . is an example of a parthenocarpic fruit.

Statement-$X$: The seeds of some plants like orchids do not contain stored food.
Statement-$Y$: The embryo present in their seeds is extracted and grown in a culture medium.

Which plant seeds possess perisperm?