Anatomy means study of Internal features. This includes internal organs, types of tissues, different types of cells that are found in an organism.
In this chapter, we study Anatomy of flowering plants, that is Angiosperms. Angiosperms are the only type of plants that produce flower.
The main topics of this chapter are-
1. The Tissues
2. The Tissue System
3. Anatomy of Dicotyledonous and Monocotyledonous Plants
4. Secondary Growth
The tissue is a group of cells having a common origin and performing a common function.
Types of tissue - Meristematic Tissues and Permanent tissue, Simple tissue and Complex tissue.
Vascular bundles having Xylem, Phloem are important for exam. Also, different types of cells like Parenchyma, Collenchyma and schrelenchyma are also important.
Then NCERT explains Tissue systems. These are - Epidermal Tissue systems, Ground tissue system and Vascular tissue system.
Then we study anatomy of root and stem of dicot and monocot plants.
Leaf is of two types - Dorsiventral lead found in dicotyledonous plants and Isobilateral leaves, found in monocotyledonous plants.
Leaf has Mesophyll cells. There are two types of Mesophyll - Spongy Mesophyll and Palisade Mesophyll. Palisade cells are stacked with little space between then. Spongy cells have large intercellular spaces.
In monocot plants, Mesophyll is not differentiated to spongy and palisade.
In dicot plants, stomatal pore is more at lower surface of leaf than upper upper surface, however in monocot leaves, number of stomata is equal both sides.
Secondary growth refers to growth in girth of plant. It is seen in dicot plants only. Monocots don't show secondary growth due to absence of cambium.
In the spring season, cambium is very active and produces a large number of xylary elements having vessels with wider cavities. The wood formed during this season is called spring wood or early wood. In winter, the cambium is less active and forms fewer xylary elements that have narrow vessels, and this wood is called autumn wood or late wood.
The 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. This is called Heartwood.
The peripheral region of the secondary xylem, is lighter in colour and is known as the sapwood.
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Some previous year questions are given for you to analyse your preparation.
1. Phloem in gymnosperms lacks
(a) both sieve tubes and companion cells
(b) albuminous cells and sieve cells
(c) sieve tubes only
(d) companion cells only.
2. Meristematic tissue responsible for increase in girth of tree trunk is
(a) intercalary meristem (b) lateral meristem
(c) phellogen (d) apical meristem
3. At maturity, which of the following is non-nucleated?
(a) Palisade cell (b) Cortical cell
(c) Sieve cell (d) Companion cell
4. Closed vascular bundles lack
(a) ground tissue (b) conjunctive tissue
(c) cambium (d) pith
5. Casparian strip occurs in a
(a) endodermis (b) exodermis
(c) pericycle (d) epidermis
6. The vascular cambium normally gives rise to
(a) primary phloem (b) secondary xylem
(c) periderm (d) phelloderm
7. Vascular cambium produces
(a) primary xylem and primary phloem
(b) secondary xylem and secondary phloem
(c) primary xylem and secondary phloem
(d) secondary xylem and primary phloem.
8. As compared to a dicot root, a monocot root has
(a) more abundant secondary xylem
(b) many xylem bundles
(c) inconspicuous annual rings
(d) relatively thicker periderm.
9. The transverse section of a plant shows following anatomical features :
(i) Large number of scattered vascular bundles surrounded by bundle sheath
(ii) Large conspicuous parenchymatous ground tissue
(iii)vascular bundles conjoint and closed
(iv) phloem parenchyma absent
Identify the category of plant and its part.
(a) Monocotyledonous stem
(b) Monocotyledonous root
(c) Dicotyledonous stem
(d) Dicotyledonous root
10. Palisade parenchyma is absent in leaves of
(a) mustard (b) soybean
(c) gram (d) Sorghum.
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