108 Questions
What is the most common cell and tissue type among ground tissues?
Parenchyma cells
What is the main function of parenchyma cells?
Multipurpose - Photosynthetic, Storage, Secretory
What type of tissue contains extensive air spaces, usually found in aquatic plants?
Aerenchyma
In what type of plant tissue do transfer cells develop irregular extensions of the inner wall?
Chlorenchyma
Which type of simple tissue provides flexible support, especially in herbaceous plants?
Collenchyma
What is the main function of sclerenchyma cells?
Support
Where does the vascular cambium arise?
Vascular cambium arises between primary xylem and primary phloem.
What is the function of rays in vascular tissue?
Rays function in lateral conduction and food storage.
What is the primary function of the epidermis?
The epidermis is the protective layer that covers all plant organs.
What is the role of cutin in the epidermis?
Cutin is a fatty substance on the surface of the outer epidermal walls that forms a waxy cuticle, preventing water loss and providing resistance to bacteria and fungi.
What is the function of root hairs on epidermal cells?
Root hairs increase the absorptive area of the root surface.
What is the role of lenticels in the periderm?
Lenticels are loosely arranged pockets of parenchyma cells that form by the cork cambium and protrude through the surface of the periderm.
What is the function of the root cap?
The root cap protects the tissues from damage as the root grows and secretes a lubricating mucilage.
What are the three meristematic areas found in the region of cell division in the root?
The three meristematic areas are the protoderm, ground meristem, and procambium.
What are the two main lateral meristems found in plant roots and stems?
The two main lateral meristems are the vascular cambium and the cork cambium.
What is the primary function of the vascular cambium?
The vascular cambium produces secondary vascular tissues that function primarily in support and conduction.
What type of meristem do grasses and related plants have instead of vascular and cork cambium?
Grasses and related plants have intercalary meristems instead of vascular and cork cambium.
What is the function of the cork cambium?
The cork cambium produces bark.
What are the major groups of organs in plants?
Roots, Stems, Leaves, Flowers
What are meristematic tissues and what is their function?
Meristematic tissues are regions of growth with active cell division, acting as 'stem cells'. They produce new cells for root and shoot growth.
Where are Apical Meristems (AM) located?
At the tips of roots and shoots.
What are the two main types of vascular tissues in plants?
Xylem and phloem
What do primary meristems develop from?
Primary meristems develop from apical meristems.
What are the functions of Ground Tissue in plants?
Parenchyma for photosynthesis, Collenchyma for food storage, and Sclerenchyma for support and structure protection.
What is the primary function of xylem tissue?
Conducting water and minerals absorbed by the roots
What is the role of Vascular Tissue in plants?
Vascular tissue transports water and minerals (Xylem tissue) and food (Phloem tissue).
What are the components of xylem tissue?
Parenchyma cells, fibers, vessels, tracheids, and ray cells
What are the characteristics of vessel elements in xylem?
They have thick secondary cell walls, are open at both ends, have irregular secondary walls, and have perforation plates between end walls.
What is the primary function of phloem tissue?
Conducting dissolved food materials produced by photosynthesis throughout the plant
What are the key features of sieve tube members in phloem tissue?
They lack secondary cell walls and nuclei, form sieve tubes by laying end to end, have sieve plates with small pores, and have companion cells that aid in food conduction.
The ______ covers each root tip and protects tissues from damage as the root grows.
root cap
The region of cell division in the root is composed of the ______ meristem at the center of the root tip.
apical
The ______ cambium produces secondary vascular tissues that function in support and conduction.
vascular
Grasses and related plants do not have vascular cambium or cork cambium, but instead have ______ meristems.
intercalary
The ______ meristem gives rise to the epidermis in the region of cell division.
protoderm
The ______ cambium produces the bark of stems and roots.
cork
Parenchyma cells are the most common cell and ______ type.
tissue
Collenchyma cells have unevenly thick primary cell walls and provide ______ support.
flexible
Sclerenchyma cells have thick secondary walls impregnated with ______.
lignin
Sclereids are sclerenchyma cells that are as long as ______.
wide
Fibers are sclerenchyma cells that are much longer than ______ and contain a lumen.
wide
Complex tissues are composed of two or more kinds of ______.
cells
Xylem is the conducting tissue for ______ and minerals absorbed by the roots
water
Vessels in xylem are long tubes made of vessel elements with thick secondary cell walls and are open at both ______
ends
Tracheids in xylem have tapered ends and pairs of ______ that allow water to pass from cell to cell
pits
Phloem conducts dissolved food materials produced by photosynthesis throughout the plant and is composed of sieve tube members and ______ cells
companion
Sieve Tube Members in phloem lack secondary cell walls and nuclei, and their walls have sieve plates with small ______
pores
Herbaceous dicots have discrete vascular bundles arranged in a ______
cylinder
Plants have three or four major groups of organs: – Roots, Stems, Leaves, ______, Flowers
Flowers
What is the primary function of meristematic tissues?
To allow for continuous growth and cell division
Which tissue system is responsible for the transport of water and minerals in plants?
Vascular tissue
What is the primary function of the epidermis?
Protection and prevention of water loss
What is the primary function of the root cap?
Protecting tissues from damage
Which tissue system is primarily responsible for photosynthesis and food storage in plants?
Ground tissue
Which type of meristem gives rise to the primary xylem and primary phloem?
Procambium
What is the primary function of sclerenchyma cells?
Structural support and protection
What do Grasses and related plants lack compared to other plants?
Vascular Cambium
Which tissue system gives rise to the epidermis in the region of cell division?
Protoderm
What is the main function of Cork Cambium in plant stems and roots?
Producing bark
What is the primary function of the Vascular Cambium in plants?
Producing secondary vascular tissues
What is a key characteristic of parenchyma cells?
May differentiate into other cell types
Which type of plant tissue contains sclereids, also known as stone cells?
Sclerenchyma
What is the primary function of collenchyma cells in plants?
Providing flexible support
Which simple tissue type develops irregular extensions of the inner wall to increase surface area?
Transfer cells
What differentiates sclerenchyma cells from parenchyma cells?
Containing lignin in thick secondary walls
Which type of cell in sclerenchyma tissues is scattered and as long as it is wide?
Fibers
What is the primary function of the vascular cambium?
To produce secondary xylem and phloem
What is the primary function of lenticels in the periderm?
To allow gas exchange between the plant and the environment
What is the primary function of cutin in the epidermis?
To prevent water loss by evaporation and provide bacterial/fungal resistance
What is the function of rays in vascular tissue?
To provide lateral conduction and food storage
Which of the following is NOT a function of secretory cells in the epidermis?
Transporting water and minerals
What is the primary function of root hairs on epidermal cells?
To increase the absorptive area of the root surface
What is the primary function of xylem tissue?
Conducting water and minerals absorbed by the roots
What are vessel elements in xylem characterized by?
Thick secondary cell walls, open at both ends
What is the function of sieve tube members in phloem tissue?
Conducting dissolved food materials
What is the main difference between tracheids and vessels in xylem tissue?
Tapered ends and pairs of pits
What is the composition of xylem tissue?
Parenchyma cells, fibers, vessels, tracheids
What is the characteristic feature of sieve plates in phloem tissue?
Small pores for nutrient transport
What is the function of the root cap?
To protect the root tip and secrete lubricating mucilage
Which meristematic area in the region of cell division gives rise to the epidermis?
Protoderm
What type of meristems do grasses and related plants have instead of vascular and cork cambium?
Intercalary meristems
Which of the following is a function of the vascular cambium?
Producing secondary vascular tissues for support and conduction
What is the primary function of the cork cambium?
Producing the bark of stems and roots
Which tissue system is responsible for photosynthesis and food storage in plants?
Ground tissue
What is the primary function of parenchyma cells?
Photosynthesis
Which type of simple tissue provides flexible support, especially in herbaceous plants?
Collenchyma
What is the main function of sclerenchyma cells in plants?
Support
Which type of simple tissue contains chloroplasts and is involved in photosynthesis?
Chlorenchyma
What distinguishes sclereids from fibers in sclerenchyma tissue?
Contain lumen
Where would you expect to find collenchyma cells most abundantly in a plant?
Stems
What is the primary function of Meristematic Tissues in plants?
Active cell division
Which tissue system is responsible for the transport of food in plants?
Vascular Tissue
What is the main difference between Primary Meristems and Basic Plant Tissues?
Primary Meristems produce primary tissues, while Basic Plant Tissues are responsible for active cell division.
Which plant tissue is responsible for regeneration and providing support and structure?
Collenchyma
What differentiates Vascular Tissue from Ground Tissue in plants?
Ground Tissue is responsible for transport, while Vascular Tissue provides support.
Which region of the plant contains Apical Meristems that produce new cells for primary growth?
Roots and shoots
What are the main components of xylem tissue?
Parenchyma cells, fibers, vessels, and tracheids
What is the primary function of vessels in xylem tissue?
To conduct water and minerals from the roots
Which of the following is a characteristic feature of vessel elements in xylem tissue?
Thick secondary cell walls with spiral thickenings
Where does the vascular cambium arise?
Between the primary xylem and primary phloem
What is the primary function of the vascular cambium?
To produce secondary xylem and secondary phloem
What is the primary function of phloem tissue?
To conduct dissolved food materials produced by photosynthesis
Which of the following is a component of phloem tissue?
Companion cells
What is the main function of rays in vascular tissue?
To function in lateral conduction and food storage
What is a key feature of sieve tube members in phloem tissue?
Lack of nuclei and secondary cell walls
What is the role of cutin in the plant epidermis?
To prevent water loss and provide resistance to bacteria/fungi
What is the primary function of root hairs on epidermal cells?
To increase the absorptive area of the root surface
What is the main function of cork cambium in plant stems and roots?
To replace the epidermis and form the outer bark
Study Notes
Apical Meristems
- Apical meristems are permanent regions of growth, characterized by active cell division and "stem cells"
- Located at the tips of roots and shoots
- Responsible for increasing the length of roots and shoots through the production of new cells (1° growth)
Primary Meristems
- Develop from apical meristems
- Produce primary tissues
- Composed of:
- Protoderm (gives rise to epidermis)
- Ground meristem (gives rise to cortex and pith)
- Procambium (gives rise to primary xylem and primary phloem)
Tissue Systems
- Plant cells → Tissues → Organs
- 4 regions:
- Epidermis (dermal tissue)
- Ground tissue (parenchyma, collenchyma, sclerenchyma)
- Vascular tissue (xylem and phloem)
- Periderm (outer bark)
Ground Tissues
- Parenchyma cells:
- Most common cell type
- Thin, pliable walls
- Living cytoplasm with large vacuoles and secretions
- Multipurpose (photosynthesis, storage, secretion)
- Can differentiate into other cell types
- Collenchyma cells:
- Long-lived with living cytoplasm
- Often elongated with unevenly thick cell walls
- Provide flexible support in herbaceous plants
- Sclerenchyma cells:
- Thick, tough, secondary walls
- Dead at maturity, function in support
- Two types: sclereids (stone cells) and fibers
Vascular Tissues
- Xylem:
- Conducting tissue for water and minerals
- Composed of parenchyma cells, fibers, vessels, tracheids, and ray cells
- Vessels: long tubes made of vessel elements with thick secondary cell walls
- Tracheids: tapered ends with pairs of pits for water conduction
- Phloem:
- Conducts dissolved food materials produced by photosynthesis
- Composed of sieve tube members, companion cells, fibers, and parenchyma cells
- Sieve tube members: lack secondary cell walls and nuclei, lay end-to-end to form sieve tubes
Lateral Meristems
- Produce 2° tissues that increase the girth of roots and stems (2° growth)
- Composed of vascular cambium and cork cambium
- Vascular cambium: produces 2° vascular tissues that function in support and conduction
- Cork cambium: produces bark
Intercalary Meristems
- Found in grasses and related plants
- Do not have vascular cambium or cork cambium### Vascular Tissues
- Vascular tissues include xylem and phloem
- Xylem: conducts water and minerals absorbed by roots
- Composed of: parenchyma cells, fibers, vessels, tracheids, ray cells
- Phloem: conducts dissolved food materials produced by photosynthesis throughout the plant
- Composed of: sieve tube members, companion cells, fibers, parenchyma cells, ray cells
Xylem
- Vessels: long tubes made of vessel elements
- Vessel elements: thick secondary cell walls, open at both ends, secondary walls develop irregularly, perforation plate between end walls
- Spiral thickenings on vessel walls
- Tracheids: tapered ends, pairs of pits that allow water to pass from cell to cell
- Dead at maturity, thick secondary cell walls, may have spiral thickenings on cell walls
Phloem
- Sieve Tube Members: lack secondary cell walls and nuclei, lay end to end to form sieve tubes
- Walls have sieve plates with small pores, callose forms callus plug to prevent leaking of sieve tube contents when cell is injured
- Companion cells: aid in conduction of food
Tissue Patterns in Stems
- Herbaceous Dicotyledonous Stems: discrete vascular bundles arranged in a cylinder
- Woody Dicotyledonous Stems: complex tissue patterns
Meristematic Tissues
- Apical Meristems: permanent regions of growth, active cell division, "stem cells"
- Located at tips of roots and shoots, increase in length as apical meristems produce new cells (1° growth)
- Primary Meristems: develop from apical meristems
- Protoderm, ground meristem, procambium
Ground Tissues
- Parenchyma: simple tissue, most common cell and tissue type
- Thin, pliable walls, living cytoplasm, often containing large vacuoles and various secretions
- May remain alive a long time, multipurpose: photosynthetic, storage, secretory
- Collenchyma: simple tissue, long-lived, with living cytoplasm
- Often elongated, 1° cell walls unevenly thick, pliable and strong, providing flexible support
- Sclerenchyma: simple tissue, thick, tough, secondary walls
- Impregnated with lignin, dead at maturity, function in support
- Two types: sclereids and fibers
Epidermis
- Protective layer that is one cell-layer thick, covering all plant organs
- Composed mostly of parenchyma cells, guard cells of stomata, secretory glands and hairs
- Cutin: fatty substance on the surface of outer walls of epidermis, forms waxy cuticle
- Wax secreted on cuticle prevents water loss by evaporation, provides bacterial/fungal resistance
- Root epidermal cells produce root hairs, increase absorptive area of root surface
- Leaves have stomata bordered by pairs of guard cells
- Trichomes: hair-like structures, may function individually or as part of a secretory tissue
- Secretory cells: may function individually or as part of a secretory tissue
- Flower nectar, citrus oils, glandular hair mucilage, latex, resins
Periderm
- Replaces epidermis when cork cambium begins producing new tissue
- Constitutes outer bark, primarily composed of: cork cells (phellem), cork cambium (phellogen), cork parenchyma (phelloderm)
- Lenticels: loosely arranged pockets of parenchyma cells, form by cork cambium, protrude through the surface of periderm
Explore the concept of organs and tissues in plants, including roots, stems, leaves, and flowers. Learn about the composition of organs, which consist of various tissues made up of cells with similar functions. Dive into the topic of Meristematic Tissues and Apical Meristems.
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