Characteristics of root Descending part Negatively phototrophic Non-green Root cap /root pockets Unicellular root hair No nodes Lateral roots Endogenously
Regions of typical root Root cap – mucigel to lubricate Zone of cell division Zone of elongation Zone of root hair or absorption Zone of maturation or differentiation
Functions of root Anchorage Absorption Conduction of water & minerals Transport of nutrients
Types of root system Tap root system Roots develops, usually from the radicle of an embryo of seed is called tap root & the system is called tap root system. 2. Fibrous Root System The roots which develop from any other part of the plant except the radicle is called adventitious root and this system is called adventitious or fibrous root system. eg. Monocot plants
Leaf Structure A leaf is held away from its stem by a stem-like appendage called a petiole. The base of the petiole is attached to the stem at a node. The blade is the expanded thin structure on either side of the midrib and is usually the largest, most conspicuous part of a leaf
Leaf Parts The cuticle is part of the epidermis It produces a waxy layer called cutin, which protects the leaf from dehydration and disease. On the top and bottom is a layer of thick, tough cells called the epidermis. Its primary function is to protect the other layers of leaf tissue.
Leaf Parts Continued Special epidermal cells called guard cells open and close in response to environmental stimuli, such as changes in weather and light. They regulate the passage of water, oxygen, and carbon dioxide into and out of the leaf through tiny openings called stomata. Located between the upper and lower epidermis is the mesophyll. Located within the mesophyll cells are chloroplasts, where photosynthesis takes place.