Describe the internal structure of a dorsiventral leaf with the help of labelled diagrams.
[question] Question. Describe the internal structure of a dorsiventral leaf with the help of labelled diagrams. [/question] [solution] Solution: Dorsiventral leaves are found in dicots. The vertical section of a dorsiventral leaf contains three distinct parts. [1] Epidermis: Epidermis is present on both the upper surface (adaxial epidermis) and the lower surface (abaxial epidermis). The epidermis on the outside is covered with a thick cuticle. Abaxial epidermis bears more stomata than the adaxia...
What is periderm?
[question] Question. What is periderm? How does periderm formation take place in dicot stem? [/question] [solution] Solution: Periderm is composed of the phellogen, phellem, and phelloderm. During secondary growth, the outer epidermal layer and the cortical layer are broken because of the cambium. To replace them, the cells of the cortex turn meristematic, giving rise to cork cambium or phellogen. It is composed of thin-walled, narrow and rectangular cells. Phellogen cuts off cells on its either...
How is the study of plant anatomy useful to us?
[question] Question. How is the study of plant anatomy useful to us? [/question] [solution] Solution: The study of plant anatomy helps us to understand the structural adaptations of plants with respect to diverse environmental conditions. It also helps us to distinguish between monocots, dicots, and gymnosperms. Such a study is linked to plant physiology. Hence, it helps in the improvement of food crops. The study of plant-structure allows us to predict the strength of wood. This is useful in ut...
Name the three basic tissue systems in the flowering plants.
[question] Question. Name the three basic tissue systems in the flowering plants. Give the tissue names under each system. [/question] [solution] Solution: [/solution]...
What is stomatal apparatus?
[question] Question. What is stomatal apparatus? Explain the structure of stomata with a labelled diagram. [/question] [solution] Solution: Stomata are small pores present in the epidermis of leaves. They regulate the process of transpiration and gaseous exchange. The stomatal pore is enclosed between two bean-shaped guard cells. The inner walls of guard cells are thick, while the outer walls are thin. The guard cells are surrounded by subsidiary cells. These are the specialised epidermal cells ...
Why are xylem and phloem called complex tissues?
[question] Question. Why are xylem and phloem called complex tissues? [/question] [solution] Solution: Xylem and phloem are known as complex tissues as they are made up of more than one type of cells. These cells work in a coordinated manner, as a unit, to perform the various functions of the xylem and phloem. Xylem helps in conducting water and minerals. It also provides mechanical support to plants. It is made up of the following components: Tracheids (xylem vessels and xylem tracheids) Xylem ...
The transverse section of a plant material shows the following anatomical features,
[question] Question. The transverse section of a plant material shows the following anatomical features, (a) the vascular bundles are conjoint, scattered and surrounded by sclerenchymatous bundle sheaths (b) phloem parenchyma is absent. What will you identify it as? [/question] [solution] Solution: The monocot stem is characterised by conjoint, collateral, and closed vascular bundles, scattered in the ground tissue containing the parenchyma. Each vascular bundle is surrounded by sclerenchymatous...
Cut a transverse section of young stem of a plant from your school garden and observe it under the microscope.
[question] Question. Cut a transverse section of young stem of a plant from your school garden and observe it under the microscope. How would you ascertain whether it is a monocot stem or dicot stem? Give reasons. [/question] [solution] Solution: The dicot stem is characterised by the presence of conjoint, collateral, and open vascular bundles, with a strip of cambium between the xylem and phloem. The vascular bundles are arranged in the form of a ring, around the centrally-located pith. The gro...
Draw illustrations to bring out anatomical difference between
[question] Question. Draw illustrations to bring out anatomical difference between (a) Monocot root and dicot root (b) Monocot stem and dicot stem [/question] [solution] Solution: (a)Monocot root and dicot root (b)Monocot stem and dicot stem [/solution]...
Explain the process of secondary growth in stems of woody angiosperm with help of schematic diagrams. What is the significance?
[question] Question. Explain the process of secondary growth in stems of woody angiosperm with help of schematic diagrams. What is the significance? [/question] [solution] Solution: In woody dicots, the strip of cambium present between the primary xylem and phloem is called the interfascicular cambium. The interfascicular cambium is formed from the cells of the medullary rays adjoining the interfascicular cambium. This results in the formation of a continuous cambium ring. The cambium cuts off n...
Cork cambium forms tissues that form the cork. Do you agree with this statement? Explain.
[question] Question. Cork cambium forms tissues that form the cork. Do you agree with this statement? Explain. [/question] [solution] Solution: When secondary growth occurs in the dicot stem and root, the epidermal layer gets broken. There is a need to replace the outer epidermal cells for providing protection to the stem and root from infections. Therefore, the cork cambium develops from the cortical region. It is also known as phellogen and is composed of thin-walled rectangular cells. It cuts...
State the location and function of different types of meristem.
[question] Question. State the location and function of different types of meristem.\ [/question] [solution] Solution: Meristems are specialised regions of plant growth. The meristems mark the regions where active cell division and rapid division of cells take place. Meristems are of three types depending on their location. Apical meristem It is present at the root apex and the shoot apex. The shoot apical meristem is present at the tip of the shoots and its active division results in the elonga...