Brooks Biodiversity Unit 3 Exam Questions and Correct Answers 2024 with complete solution.

Brooks Biodiversity Unit 3 Exam Questions and Correct Answers 2024 with complete solution. Plants Architecture Plant needs i. collection & conversion of solar energy -> leaves ii. positioning & support of leaves -> stems iii. anchorage & absorption -> roots iv. transport -> vascular system Leaf Structure Epidermis, Mesophyll, and Vein (Vascular Bundle) Epidermis contains what? - Cuticle - Guard cells with Stomata Epidermis outermost cell layer of a plant body cutin: (wax) excreted by epidermis Cuticle Waxy waterproof covering of a plant. Produced by the epidermis and has wax to resist desiccation. Guard Cells Responsible for opening and closing stomata. Works together with stomata to regulate gas exchange. Prevents movement of water ACROSS surface Stomata Small openings on the underside of a leaf through which oxygen and carbon dioxide can move. Mostly on lower surfaces, sometimes on upper surfaces. Found on both surfaces. Allows for gas exchange. 2 aspects of Photosynthesis light dependent reactions light independent reactions Mesophyll contains what? - Parenchyma - Dicots have Palisade & Spongy Layers Mesophyll Middle leaf structures photosynthetic layer. Parenchyma Ground tissue that forms the bulk of the mesophyll Can be modified into collenchyma and sclerenchyma Thin and flexible cells Most common and versatile ground tissue Used for metabolic functions and storage of organic products Palisade & Spongy layers Palisade layer: where light dependent reactions occur, near the surface. Top part of the mesophyll in dicot plants. Spongy mesophyll or spongy parenchyma: soft lower layer. Has access to CO2 through stomata. Kelvin Cycle: where carbon fixation occurs, converting nonorganic CO2 into sugars. Vein (Vascular bundle) Transports materials throughout the leaf and contains the xylem and phloem. Separating the VB = damage. Stem Structure Epidermis, Cortex, Collenchyma, Sclerenchyma, Vascular Tissues Xylem (Xylem Up) Distributes water from roots throughout Aimed towards stem Red Tells age of tree Contains: tracheids & vessel members Tracheids Thin, hollow, narrow tube, dead cells with perforated, tapered ends. Vestigial structure First kind of tube made Present in early vascular plants and present in angiosperms and gymnosperms (slow flow) Vessel Members Thick, hollow, wide tube, dead cells with large holes on end. Clearly visible Phloem (Phloem Down) Distributes the products of photosynthesis (sugary water) to plants tissues. Blue Contains: Sieve tube members (element) & Companion cells Sieve Tube Members hollow, living cells with perforated cells Companion Cells living cells that help keep sieve tube member cells alive. Production of sugars in Kelvin Cycle require transportation done by companion cells into phloem Which 4 cell types is most active metabolically when fully functional? companion cells Epidermis in Trees is replaced by bark or cork. Produced by the cork cambium (tissues that produce other tissues). Cork (dead) = phloem (alive) Cork cambium produces cork. Trees grow wider cause xylem will get clogged The cork is produced when? Secondary phloem Composition of Bark is produced from phloem, cork cambium, or cork. Lenticels cracks in the bark to facilitate gas exchange Secondary Growth How a plant increases in girth (diameter) 1. Vascular Cambium 2. Cork Cambium 3. Wood 4. Bark 5. Lenticels 6. "Girdling Plants" Wood produced by xylem. annual rings Heartwood: clogged xylem, little water transport. Located deeper into trunk, harder wood Sapwood: newer xylem, free flowing water transport. Phloem makes sap. Girdling Plants Weed-Whakers Cutting a HORIZONTAL band around the circumference of the plant, can be deadly because the vascular cambium, in which nutrients and water travel vertically, can be damaged. What happens to initial phloem? it gets crushed What happens to the xylem? it gets clogged Cortex Yellow layer inside epidermis Separated by a ring of vascular bundles. Ground Tissue System Includes various cells specialized for functions such as storage, photosynthesis, and support Types of Ground Tissue Parenchyma, Collenchyma, Sclerenchyma Collenchyma celery fibers for support Sclerenchyma hard fibers & nodules responsible for support (ex) rope Sclerids nodules glued together to form shells of nuts. Fibers secretions that reinforce the stem