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Describe the role of an apical but, auxiliary bud and apical dominance.
- An axillary bud is a structure that has potential to form a lateral shoot, or branch
- An apical bud, or terminal bud, is located near the shoot tip and causes elongation of a young shoot
- Apical domincance helps to maintain dormancy in most nonapical buds
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Describe the components (tissues) and roles of dermal, vascular and ground tissue in plants.
- Monocots and eudicots differ in the arrangement of veins, the vascular tissue of leaves
- Most monocots have parallel veins
- Most eudicots have bnranching veins
- Each plant organ has dermal, vascular, and ground tissues
- Each of these three categories forms a tissue system
- The vascular tissue system carries out long-distance transport of materials between roots and shoots
- The two vascular tissues are xylem and phloem
- Xylem conveys water and dissolved minerals upward from roots into the shoots
- Phloem transports organic nutrients from where they are made to where they are needed
- Tissues that are neither dermal nor vascular are the ground tissue system
- Ground tissue internal to vascular tissue is pith; ground tissue external to the vascular tissue is cortex
- Ground tissue includes cells specialized for storage, photsynthesis, and support
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How do Parenchyma, Collenchyma, and Sclerenchyma cells differ?
- Some major types of plant cells:
- Parenchyma
- Collenchyma
- sclerenchyma
- Water-conducting cells of the xylem
- Sugar-conducting cells of the phloem
- Mature parenchyma cells
- have thin and flexible primary walls
- Lack secondary walls
- Are the least specialized
- Perform the most metabolic functions
- Retain the ability to divide and differentiate
- Collenchyma cells are grouped in strands and help support young parts of the plant shoot
- They have thicker and uneven cell walls
- The lack secondary walls
- These cells prived flexible support without restraining growth
- Sclerenchyma cells are rigid because of thick secondary walls stregthened with lignin
- They are dead at functional maturity
- There are two types:
- Sclereids are short and irregular in shape and have thich lignified secondary walls
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