Question.3 (a) Why are angiosperms so called ? In which structures do the seeds develop ? Why are cotyledons considered an important part of seed ?
(b) Differentiate between the two categories of angiosperms giving an example of each. 

Solution:

a. The term 'Angiosperm' has been derived from a greek composite word (angeion-, "case" or "casing", and sperma, "seed") which means "enclosed seeds". Thus, angiosperms mean those plants that produce seeds within an enclosure, i.e., they are fruiting plants.

Angiosperms have a carpel that encloses developing seeds that may turn into a fruit, i.e., their reproductive structures are flowers in which the ovules are enclosed in an ovary.

A cotyledon is part of the embryo within the seed of the plant. They are the first part of the plants to emerge from the soil and give way to other plant growth. Some cotyledons may last only for few days, while others may last for years.

The cotyledons are important for the new growing plant because they contain the stored food from the seed which is required for the initial burst of energy to grow.

b. Two categories of Angiosperms are-Dicots and Monocots
 

Dicots	Monocots
The seeds of these plants have two cotyledons.	The seeds of these plants have a single cotyledon.
The dicot plants mostly have tap root system.	Monocot plants mostly have fibrous root system.
The leaves have reticulate venation.	The leaves have parallel venation.
Examples include roses, peas, sunflowers, oaks, etc.	Examples include lilies, orchids, agaves, etc.