BSC-116-001 Chapter 35 – Flashcards
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Key Concepts
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35.1 Plants have a hierarchical organization consisting of organs, tissues, and cells.
35.2 Different meristems generate new cells for primary and secondary growth.
35.3 Primary growth lengthens roots and shoots.
35.4 Secondary growth increases the diameter of stems and roots in woody plants.
35.5 Growth, morphogenesis, and cell differentiation produce the plant body.
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Organ
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A specialized center of the body function composed of several different types of tissues.
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Tissue
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An integrated group of cells with a common structure, function, or both.
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Root system
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All of a plants roots, which anchor it in the soil, absorb and transport minerals and water, and store food.
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Root
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An organ in vascular plants that anchors the plant and enables it to absorb water and minerals from the soil.
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Shoot system
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The aerial portion of a plant body, consisting of stems, leaves, and flowers (in angiosperms).
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Root hairs
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A tiny extension of a root epidermal cell, growing just behind the root tip and increasing surface area for absorption of water and minerals.
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Plant
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A vascular plant organ consisting of an alternating system of nodes and internodes that support the leaves and reproductive structures.
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Nodes
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A point along the stem of a plant at which leaves are attached.
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Internodes
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A segment of a plant stem between the points where leaves are attached.
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Apical bud
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A bud at the tip of a plant stem; also called terminal buds. Where most of the growth of a young shoot occurs.
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Axillary bud
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A structure that has the potential to form a lateral shoot , or branch. The bud appears in the angle between a leaf and a stem.
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Leaf
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The main photosynthetic organ of a vascular plant.
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Blade
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The flattened portion of a typical leaf.
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Petiole
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The stalk of the leaf, which joins the leaf to the node of the stem.
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Dermal tissue system
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The outer protective covering of plants.
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Epidermis
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The dermal tissue system of a non-woody plants, usually consisting of a single layer of tightly packed cells.
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Stele
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The vascular tissue system of a stem or root.
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Ground tissue system
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Plant tissues that are neither vascular nor dermal, fulfilling a variety of functions, such as storage, photosynthesis, and support.
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Pith
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Ground tissue that is internal to the vascular tissue in a stem; in many monocot roots, parenchyma cells that form the central core of the vascular cylinder.
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Cortex
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In plants, ground tissue that is between the vascular tissue and dermal tissue in a root or eudicot stem.
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Determinate growth
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A type of growth characteristic of most animals and some plant organs, in which growth stops after a certain size is reached.
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Apical meristems
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Embryonic plant tissue in the tips of roots and buds of shoots. The dividing cells of an apical meristem enable primary growth (to grow in length).
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Lateral meristems
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A meristem that thickens roots and shoots of woody plants. The vascular cambium and cork cambium are lateral meristems.
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Vascular cambium
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A cylinder of meristematic tissue in woody plants that adds layers of secondary xylem (wood) and secondary phloem.
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Cork cambium
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A cylinder of meristematic tissue in woody plants that replaces the epidermis with thicker, tougher, cork cells.
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Root cap
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A cone of cells at the tip of a plant root that protects and apical meristem. Also, secrets a polysaccharide slime that lubricates the soil around the tip of the root.
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Annuals
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Complete their life cycles in a year or less. (wild flowers and most staple crops).
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Biennials
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Generally require two growing season to complete their life cycle, flowering and fruiting only in their second year. (Turnips)
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Perennials
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Live many years and include trees, shrubs, and some grasses.
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Endodermis
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In plant roots, the innermost layer of the cortex that surrounds the vascular cylinder.
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Pericycle
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The outermost layer in the vascular cylinder, from which lateral roots arise.
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Leaf primordia
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A finger like projection along the flank of a shoot apical meristem, from which a leaf arises.
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Mesophyll
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Leaf cells specialized for photosynthesis. Located between upper and lower epidermis.
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Most of the growth of a plant body is the result of
A. cell differentiation.
B. morphogenesis.
C. cell division.
D. cell elongation.
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D. cell elongation
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The innermost layer of the root cortex is the
A. core.
B. pericycle.
C. endodermis.
D. pith.
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C. endodermis.
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Heartwood and sapwood consist of
A. bark.
B. periderm.
C. secondary xylem.
D. secondary phloem.
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C. secondary xylem.
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The phase change of an apical meristem from the juvenile to mature vegetative phase is often revealed by
A. a change in the morphology of the leaves produced.
B. the initiation of secondary growths
C. the formation of lateral roots.
D. the activation of floral meristem identity genes.
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A. a change in the morphology of the leaves produced.
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Suppose a flower had normal expression of genes A and C and expression of B in all four whorls. Based on the ABC hypothesis, what would be the structure of that flower, starting at the outermost whorl?
A. carpel-petal-petal-carpel
B. petal-petal-stamen-stamen
C. sepal-carpel-carpel-sepal
D. sepal-sepal-carpel-carpel
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B. petal-petal-stamen-stamen
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Which of the following arise, directly or indirectly, from meristematic activity?
A. secondary xylem
B. leaves
C. dermal tissue
D. all of the above
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D. all of the above
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Which of the following would not be seen in a cross section through the woody part of a root?
A. sclerenchyma cells
B. parenchyma cells
C. sieve-tube elements
D. root hairs
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D. root hairs
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Root hairs are important to a plant because they _____.
A. protect the plant from soil microbes
B. help the root slide between soil particles
C. develop into lateral roots
D. increase the surface area for absorption
E. protect the plant from freezing
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D. increase the surface area for absorption
Root hairs are extensions of individual epidermal cells on the root surface, which increase the absorptive surface area of the root tremendously.
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Which of the following is correctly matched with its tissue system?
A. xylem ... ground tissue system
B. phloem ... epidermis
C. pith ... vascular tissue system
D. cortex ... ground tissue system
E. guard cells ... ground tissue
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D. cortex ... ground tissue system
The cortex is composed of ground tissue.
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How do cells in a meristem differ from cells in other types of plant tissue?
A. They are growing.
B. They photosynthesize at a faster rate.
C. They store food.
D. They continue to divide.
E. They are differentiating.
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D. They continue to divide.
Meristem is embryonic tissue, and it retains the ability to divide.
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The primary growth of a plant adds _____ and secondary growth adds _____.
A. height ... branching
B. branching ... flowers
C. girth ... height
D. branching ... girth
E. height ... girth
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E. height ... girth
Apical meristems elongate shoots and roots through primary growth. Lateral meristems add girth to woody plants through secondary growth.
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Which of the following is not a type of primary meristematic cell found in apical meristems?
A. Procambium
B. Vascular cambium
C. Protoderm
D. Ground meristem
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B. Vascular cambium
The vascular cambium is a type of cell found in lateral (not apical) meristems and is involved in secondary (not primary) growth.
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Which structure determines the direction of root growth by sensing gravity?
A. Mucigel
B. Root hairs
C. Root cap
D. Pith
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C. Root cap
The root cap is a layer of protective cells that determines the direction of root growth by sensing gravity.
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True or false? Plant growth involves both the production of new cells by mitosis and the expansion of cell volume.
A. True
B. False
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A. True
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Which of the following statements about the vascular cambium is true?
A. It is a type of apical meristem.
B. It is located between the primary xylem and cortex.
C. It develops into cork cells on the outside of the cortex.
D. It is a layer of undifferentiated cells that develops into secondary xylem and phloem.
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D. It is a layer of undifferentiated cells that develops into secondary xylem and phloem.
Vascular cambium is a type of lateral meristem that produces secondary xylem and phloem in a plant.
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Why do plants need secondary growth?
A. To produce a more extensive root system
B. To produce new leaves
C. To provide structural support for the plant
D. To grow taller
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C. To provide structural support for the plant
Structural support in the form of widening stems and roots is achieved through secondary growth.
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Which of the following parts of a plant remains on the plant even after several years of growth?
A. Cortex
B. Primary phloem
C. Epidermis
D. Primary xylem
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D. Primary xylem
The primary xylem is located close to the pith of the plant and remains a part of the plant even after several years of growth.
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True or false? Primary growth can occur at both the apical and lateral meristems at the tips of the roots and stems in a plant.
A. True
B. False
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B. False
Primary growth results in increased length and occurs only at the apical meristems at the tips of the roots and stems in a plant.
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Primary growth
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1.) apical meristem
2.) elongation
3.) increases exposure to light
4.) occurs in plants that live only one year
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Secondary growth
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1.) later meristem
2.) vascular cambium
3.) cork cambium
4.) growth in thickness
5.) increases vascular flow
6.) provides structural support
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Other than the transport of materials, what is another function that vascular tissue performs in a leaf?
A. The tissue stores sugars produced by photosynthesis.
B. The tissue contains the cells that perform photosynthesis.
C. The tissue functions as a skeleton that reinforces the shape of the leaf.
D. The tissue contains a labyrinth of air spaces that allows for gas exchange.
D. The tissue regulates the opening and closing of pores in stomata complexes.
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C. The tissue functions as a skeleton that reinforces the shape of the leaf.
Veins in leaves (vascular bundles) transport materials and provide support.
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Cell division in the vascular cambium adds to the girth of a tree by adding new _____ to the layer's interior and _____ to the layer's exterior.
A. xylem ... phloem
B. phloem ... xylem
C. pith ... xylem and phloem
D. xylem and phloem ... bark
E. xylem ... cortex
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A. xylem ... phloem
The vascular cambium produces xylem at its interior and phloem at its exterior.
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As the epidermis is pushed outward and sloughed off, it is replaced by tissues produced by the _____.
A. cork cambium
B. lenticels
C. pith
D. suberin
E. vascular cambium
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A. cork cambium
The cork cambium produces the phelloderm, phellogen, and cork cells. These cells move outward to replace epidermal cells.
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Cellular differentiation and morphogenesis in plants depends primarily on _____.
A. regulation of gene expression
B. symmetrical cell division
C. clonal analysis
D. developmental phase changes
E. changes in the genomes of different cells in different parts of the plant
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A. regulation of gene expression
The DNA of all the somatic cells in a plant is the same. What changes during cell differentiation is which genes are turned on and which genes are turned off.
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Select the best description of the significance of the meristems of plants.
A. Plant meristems are permanently embryonic regions within the plant body.
B. Plant meristems are present only in young plants.
C. Plant meristems are active only for repair of wounds or damage to plants.
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A. Plant meristems are permanently embryonic regions within the plant body.
In plants, unlike in most animals, growth is not limited to an embryonic or juvenile period. Growth occurs throughout the plant's life, a process known as indeterminate growth. This indeterminate growth is possible because, unlike animals, plants have perpetually undifferentiated tissues called meristems. Read about plant meristems.
