Anatomy of Flowering Plants Test 2

In plants respiratory organs in stem is called lenticels. They are located as pores in the bark of plants.

Separate xylem and phloem bundles are found in dicotyledonous roots. This kind of vascular bundle is called radial vascular bundle.

The tissues involved in secondary growth are the two lateral meristems namely, vascular cambium and cork cambium.

In conjoint type of vascular bundles,the xylem and phloem are situated at the sameradius of vascular bundles. Such vascularbundles are common in stems and leaves. Theconjoint vascular bundles usually have thephloem located only on the outer side of xylem.

The abaxial epidermis generally bears more stomata than the adaxial epidermis.

Quiescent centre is a small group of cells with low mitotic activity. It is found at the tips of growing roots in the root meristem.

The wood is actually a secondary xylem. There are different types of wood on the basis of their composition and time of production.

Xylem is a complex tissue, which consists of four kinds of cells. These cells are tracheid, vessels, xylem parenchyma and xylem fibers. Companion cell is part of phloem tissue.

The tangential as well as radial walls of the endodermal cells have a deposition of water-impermeable, waxy material-suberin-in the form of casparian strips.

Ground tissue consists of all tissues except epidermis and vascular bundle of stem and root. It forms the main parts of plant made up of

The cells of medullary cells, adjoining these intrafascicular cambium becomemeristematic and form the interfascicular cambium.

The parenchyma performs various functions like photosynthesis, storage, secretion.

In the monocotyledons, the vascular bundles have no cambium present in them. Hence, since they do not form secondary tissues they are referred to as closed.

Lucinate collenchyma is very much alike to angular collenchyma but the cells are regularly arranged. Thickening occurs at theinner and outer tangential wall. It is found in cucurbita stem.

In old trees, the greater part of secondary xylem is dark brown due to deposition of organic compounds like tannins, resins, oils, gums, aromatic substances and essential oils in the central or innermost layers of the stem. These substances make it hard, durable and resistant to the attacks of microorganisms and insects. This region comprises dead elements with highly lignified walls and is called heart wood.

Tracheids are elongated or tube like cells with thick and lignified walls and tapering ends.

In leaves, the ground tissue consists of thin-walled chloroplast containingcells are called mesophyll cells.

In Barley stem, vascular bundles are closed and scattered throughout the cortex. Cambium is absent between xylem and phloem.

As the stem continues to increase in girth due to the activity of vascular cambium, the outer cortical and epidermis layers get broken and need to be replaced to provide new protective cell layers. Hence, another meristematic tissue called cork cambium or phellogen develops in the cortex region.

 Lignin is present in sclerenchyma.

Monocotyledonous roots do not undergo any secondary growth.

The cells surrounding the stomata are called guard cells. The guard cells of inner side are thicker and that of outer side is comparatively thinner.

The cambial ring becomes active and begins to cut off new cells, both towards the inner and the outer sides. The cells cut off towards pith, mature into secondary xylem.

The part ‘A’ is protoderm in apical meristem of root.

In grasses, the guard cells are dumb-bell shaped