Class 11th Biology – 6 Anatomy of Flowering plants MCQs

Vessels are enlongated, multicellular water conducting channels with wide lumen formed by end to end fusion of a large number of vessel elements. Tracheids are elongated dead cells with tapering ends having lignified walls and large or wide lumen. Their main function is conduction of water and minerals from root to leaf.

The long, tough strands found in celery are made up of collenchyma.

Xylem parenchyma stores food materials in the form of starch,fat and other substances like tannins.

Sclerenchyma provides mechanical support to organs.

By counting the number of annual rings at base stem of a tree the age of the tree can be determined.

Heartwood differs from sapwood in having dead and non-conducting elements. In old trees, the inner region that comparises dead elements with higly lignified walls is called heartwood. Heartwood does not conduct water but gives mechanical support to the stem. On the other hand, the peripheral region, which is lighter in colour are called Sapwood. It is involved in the conduction of water and minerals from root to leaf.

Phellem (cork), phellogen(cork cambium) and phelloderm (cotex) are collectively called periderm.

Parenchymatous cells rupture and form lens shaped openings called lenticels, which permit the exchange of gases between the outer atmosphere and the internal tissue of the stem.

Waxy outermost lining, which is secreted by epidermis.

Nervous system is present in animals.

The complex tissues are made of more than one type of cells and these works together as a unit. Xylem is a complex tissue.

In collenchyma cell walls show localized thickenings due to presence of approximately 45% pectin, 35% hemicellulose and 20% cellulose.

All tissues in the plant except epidermis and vascular bundles constitute the ground tissue.

Generally gymnosperms do not have vessels but a few gymnosperms having vessels are Ephedra, Gnetum etc.Most of angiosperms have vessels except of few e.g., Trochodendron.

In barley stem, vascular bundles are closed and scattered. They are open only for a hour in the day time and never open at night. E.g Cereals.

Intercalary meristem occurs in grasses and regenerated parts removed by the grazing herbivores.

Parenchyma storage of food materials e.g., carrot, beet root, etc.

Ring porous wood is more advanced than diffuse porous wood as it provides for better translocation when requirement of plant is high.

Internally, sieve tubes possess peripheral layer of cytoplasm and are devoid of nucleus. They are living cells. Cell walls of sieve tubes are thickened than surrounding parenchyma cells.

Some groups of parenchyma cells are loosely packed together with connected air spaces. These types of cells are called aerenchyma tissue.

Epiblema is the outermost covering of the root. Cuticle and stomata are absent in epiblema and hence they produce long unicellular projections called root hairs. Hence, it is also known as piliferous layer.

Collenchyma provides mechanical strength to young dicot stems, petioles and leaves.

Sieve tubes are long distance channels for transport of organic nutrients. The moement of the nutrients are bidirectional.

Pericycle of roots is active in the formation of root branches or lateral roots.

Monocot roots have thin walled cells in the epiblema, unicellular root hairs, and distinct pith. But they do not have cuticle and stomata.

During spring, woods are lighter in colour and have lower density. In this season, cambium is active and produces a large number of xylary elements having vessels with wider cavity.

They possess hard and extremely thick secondary walls due to uniform deposition of lignin.

The conjoint type of vascular bundles is common in stems and leaves. Roots contain radial type of vascular bundles.

Chloroplast containing parenchyma(chlorenchyma) are mostly present in leaf.

Lateral meristem occurs on the sides of stem and help in increasing girth of stem and root. It divides only periclinally or radially and is responsible for increase in girth or diameter.