Morphology and Physiology of Angiosperms

They are found in fruit or seed walls and also in the flesh of apples and pineapple. The cells may be living or dead, but short and variously shaped. Their cell wall is heavily thickened with many pit lines unevenly distributed.

These are bone-like or columnar with swollen ends. For example: Sub-epidermal covering of legume seeds.

Epiblema is the outermost covering of the root formed by single layer of compactly arranged, barrel-shaped parenchyma cells. The cells are characteristically thin-walled, since they are involved in absorption of water. A cuticle and stomata are absent. Some of the epiblema cells are produced into long unicellular projections called root hairs. Hence, the epiblema is also known as piliferous layer.

Medullary parenchyma is the parenchyma which is found radially arranged in between the vascular bundles in the stem. It is meant for storage of reserve food.

Mesophyll is the ground tissue that occurs between the two epidermal layers. It is exclusively composed of chlorenchyma cells. The mesophyll is characteristically differentiated into two regions namely, an upper palisade parenchyma and a lower spongy parenchyma.

The single-celled haploid spore germinates, dividing by the normal process (mitosis), which maintains the number of chromosomes at n. The result is a multi-cellular haploid organism, called the gametophyte (because it produces gametes at maturity).

It is the innermost layer of cortex formed by compactly arranged barrel-shaped cells. Some of the cells in the endodermis are thin-walled and are known as passage cells. The passage cells allow water to pass into the xylem vessels. 

Two large green hemispherical structures which enclose the embryonic axis are called as the cotyledons. The cotyledons may be one or two in number depending on the type of plant. The cotyledons are important becausetheyt give nutrients during the early development of the plant before starting the process of photosynthesis.  

Ergastic substances are almost always present in the form of secretory products, storage products or excretory products.

Endodermis is the inner most layer of cortex represented by a single layer of compactly arranged barrel-shaped parenchyma cells. In the stem, it is meant for storage. In the root, it plays an important role in the movement of absorbed water. Some of the cells in the root endodermis contain secondary thickenings called casparian thickenings, formed by a waxy substance called suberin.

Phosphorus is important in plant bioenergetics. As a component of ATP, phosphorus is needed for the conversion of light energy to chemical energy (ATP) during photosynthesis. It is a primary macronutrient of the plants.

Manganese is necessary for photosynthesis, including the building of chloroplasts. Manganese deficiency may result in coloration abnormalities, such as discolored spots on the foliage.

Pheophytin is a chemical compound that serves as the first electron carrier intermediate in the electron transfer pathway of photosystem II (PS II) in plants and the photosynthetic reaction center (RC P870) found in purple bacteria.