Question

The leaves which bear sporangia are called
A) Sporophylls
B) Bract
C) Cone
D) Strobilus

Answer 1

A sporangium is a structure in which spores grow. It may be made up of a single cell or several cells. At any stage in their lives, both plants, fungi, and several other lineages develop sporangia.

Complete answer:
A sporangium is a structure in which spores grow. It may be made up of a single cell or several cells. At any stage in their lives, both plants, fungi, and several other lineages develop sporangia. Sporangia can create spores by mitosis, but in virtually all land plants and many fungi, sporangia are the site of meiosis, producing genetically distinct haploid spores.

Sporangia can be terminal (at the tips) or lateral (along the side) of branches, or they can be paired with leaves. Sporangia are usually located on the abaxial surface (underside) of fern leaves, where they are densely aggregated into clusters known as sori.

Now let us look into the given options:
Option A) Sporophyll : A sporangia-bearing leaf is known as a sporophyll. Sporophylls may be microphylls or megaphylls. Sporangia are sacs that contain spores (micro/male and macro/female spores). This sporangium is produced on sporophyll leaves. As a result, this is the correct answer.
Option B) Bract : Bracts (hypsophylls) are unique leaves that bear flowers at their axils. They are not necessarily present, and if one is found, the flower is called bracteate; if none are found, the flower is called ebracteate, as in the families Cruciferae and Boraginaceae. As a result, this is the incoreect answer.
Option C) Cone : A cone is an organ found on plants in the Pinophyta division that houses the reproductive structures. Hence it is the incorrect answer.
Option D) Strobilus : Strobili are often referred to as cones. As a result, this is the incorrect alternative.

Note:
- Sporophylls are not produced by all plants.
- Sporangia grow directly on roots.
- Psilotum has been thought to produce sporangia (fused in a synangium) at the tip of a stalk.