9.1 Dictotledonous Plant Structure

2. Outline 3 differences between the structures of dicotyledonous and monocotyledonous plants
Leaves: Monocots have parallel veins while Dicots have net like veins
Roots: Monocots have fibrous roots while Dicots have taproots
Flower:Monocts have floral parts in multiples of 3 while dicots have floral parts in multiples of 4 or 5
3. Explain the relationship between the distrisbution of tissues in the leaf and fucntions of these tissues
waxy cuticle:secreted by e[idermis which coevers the bottom and top of leaf, reduce water loss and imperable to water
epidermis: coveres surface of leave, secrete cuticle, protect against infection, and conserves water
palisade nesophyll:tightly packed cells in upper region of leaf, rich in hloroplasts, absorption of light, and is the primary site of photosynthesis
spony mesophyll:loosely packed calls in lower region of leaf, rich in air spaces, allowing for easy diffusion gases, less rich in chloroplasts, absorption of light, and secondary site of photosynthesis
xylem: distributes water and minerals to cells throughout leaf
phloem:collects sucrose for distribution of photosynthetic products to nonphotosynthetic parts of plant
stoma:specialize epidermal cells associated in pairs forming the borders of the stomata opening which open or close and allow gas exchange when open or water rention when closed
4. Identify modifications of roots, stems, and leaves for different functions
Bulbs:modified leaves ex onion
Tubers:modified stems ex potato
Storage root:carrot
Tendril:modified leaf ex ivy
5. State that dicotyledonous plants have apical and lateral meristems
Apical meristems are refered to primary meristems
Lateral meristems are referred to cambium
Meristems generate new cells for growth if the plant
6.Compare apical and lateral meristems in dicotylednous plants
Meristems are regions where cells continue to divide and grow
apical meristems are located at the top of the root and stem which increase the length of the plant and produce new leaves and flowers
Lateral meristems are found in vascular bundles and increase the diameter of the plant by producing xylem and phloem
7.Explain the role of auxin in phototropism as an example of the control of plant growth
Auxin is a plant hormone that stimulates plant elongation
Auxin controls phototropism which is directional grwoth toward the osource of light(phototropism)
In shoot tops proteins called phototropins that absorb light which change the shape in response to certain light wavelengths
phototropins in light induced conformation bind to reptors which stimulate trasncription/trasnlation of genes producing glycoproteins
these glycoproeins locate membranes facilitating transport of auxin between cells
shoot tips respond to light intensity by producing more auxin on the side with less light, making that side grow longer, which bends the shoot tip towards light
plant cells have membrane proteins that pump auxin laterally by which auin stimulates the pumpng of Hydrogen ions out of the cell into cell walls
hydrogen ions lower the ph which lossens connections between cellulose micofibrils
higher concentrations of auxin result in shoot to[s causing cell elongation moving them towards the light