Anatomy of Flowering Plants Biology NEET Quiz Online

Growth rings are formed by the seasonal activity of cambium. In plants of temperate regions, cambium is more active in spring and less active in autumn seasons. In temperate regions climatic conditions are not uniform throughout the year. However in tropics climatic conditions are uniform throughout the year.

Phloem in Gymnosperms lacks both sieve tube and companion cells.

Grass being a monocot, has dumb-bell shaped stomata in their leaves.

Grasses are monocots and monocots usually do not have secondary growth. Palm like monocots have anomalous secondary growth.

• Endodermis have casparian strip on radial and inner tangential wall.
• It is suberin rich.

Vascular cambium is partially secondary

• Form secondary xylem towards its inside and secondary phloem towards outsides.

• 4 – 10 times more secondary xylem is produced than secondary phloem.

Heartwood is physiologically inactive due to deposition of organic compounds and tyloses formation, so this will not conduct water and minerals.

Cork cambium undergoes periclinal division and cuts off thick walled suberised dead cork cells towards outside and it cuts off thin walled living cells i.e., phelloderm on inner side.

During secondary growth, vascular cambium gives rise to secondary xylem and secondary phloem. Phelloderm is formed by cork cambium.

Cortex is the region present between epidermis and stele.

Tyloses are balloon – shaped structures in xylem vessels developed by xylem parenchyma cells.

Few epidermal cells, in the vicinity of the guard cells become specialised in their shape and size and are known as subsidiary cells.

The stomatal aperture, guard cells and the surrounding subsidiary cells are together called stomatal apparatus.

Stem – Endarch xylem Root – Exarch xylem

Tracheids differ from vessels in being imperforate i.e, tracheids have end walls.

The process is called dendrochronology. In each year, in temperate region, two rings are formed, One in spring season (spring or early wood) Second in autumn season (autumn or late wood).

Parenchymatous cells of medullary rays get differentiated show meristematic activity and form interfascicular cambiumXylem parenchyma – Living component of xylem Endodermis – Innermost layer of cortex Pericycle – Outermost layer of stele.

Because they are present in monocots. Cycas and Pinus are gymnosperms sunflower is angiosperm (dicot).

So, no secondary growth takes place. e.g., monocots.

Because companion cells provide sieve elements nucleus for their life functions. Sieve elements and companion cells are ontogenetically related.

Also called cork cambium, which cuts off or produces cork cells towards outer side which later on become suberised.

Polyarch condition prevails in monocots.

Ground tissue is further differentiated into cortex and pith. Outermost layer of cortex is hypodermis, innermost layer of cortex is endodermis

Cork → Phellem

Cork cambium → Phellogen

Secondary cortex → Phelloderm

They have cambium, found in dicot stem

Vessels are not present in gymnosperms. Fibres are not meant for water conduction.

Transfusion tissue is present in leaves because gymnosperms lack lateral veins.

Intercalary meristem is a primary meristem, left over meristematic cells by apical meristem constitute intercalary meristem and is responsible for primary growth of plant (increase in length). Rest all are secondary meristem.

Dead because of deposition of organic secondary metabolites like resin, tannin, essential oils etc in xylem. Tracheal plugs also block vessels of heartwood and they become non conducting elements.

In root, it is towards periphery → Exarch

In stem, it is towards pith → Endarch