BOT3015 EXAM 2 Marking Scheme

BOT3015 EXAM 2 Marking Scheme What do all leaves originate as? - ANSWER-Primordia in the buds At maturity most leaves consist of - ANSWER-A stalk called the petiole and a flattened blade (lamina) A blade (lamina) consists of - ANSWER-network of veins called vascular bundle What are stipules? - ANSWER-A pair of leaf-like or thorn-like appendages are sometimes present at the base of the petiole What are sessile leaves? - ANSWER-leaves that lack petioles What are deciduous plants? - ANSWER-leaves or trees that live through one growing season What are leaves of flowering plants associated with - ANSWER-leaf gaps and they all have an axillary bud at the base What is a simple leaf? - ANSWER-a leaf with only one blade What is a compound leaf? - ANSWER-blade consists of multiple leaflets, still has a single axillary bud at it's base with the leaflets having no such buds pinnately compound leaf - ANSWER-leaf type with a divided leaf blade consisting of leaflets arranged on both sides of the midrib (rachis) Sometimes the leaflets of a pinnately compound leaf may be subdivided into smaller leaflets, forming a bipinnately compound leaf palmately compound leaf - ANSWER-leaf type with leaflets that emerge from a point, resembling the palm of a hand Epidermis - ANSWER-single layer of cells covering the entire surface of upper epidermis can be distinguished from lower epidermis by lack of stomata Photosynthesis - ANSWER-involves trapping and ultimate storing of energy in sugar molecules that are constructed from ordinary water and from carbon dioxide present in the atmosphere Stomata - ANSWER-the small openings on the undersides of most leaves through which oxygen and carbon dioxide can move water vapor evaporating from the moist interior cell surfaces can also escape via the stomata, resulting evap can cool leaf but excess water loss can damage plant Stomatal apparatus - ANSWER-2 guard cells + stoma (opening), controls the water loss when the guard cells inflate or deflate, opening or closing the pore Transpiration - ANSWER-loss of water in vapor form, most transpiration takes place through the stomata Root Pressure - ANSWER-pressure exerted in the roots of plants as the result of osmosis, causing exudation from cut stems and guttation of water from leaves