Anatomy of Flowering Plants: Class 11 Biology Q&A
32 free answers on Anatomy of Flowering Plants (Biology) for Class 11 students, across CBSE, ICSE and State boards. Includes questions such as “What are sclereids and what is their function in plants”, “What is lateral meristem and how does it differ from apical meristem?”, “How many types of cells constitute phloem and what are they?”
Question & Answer
Questions
- BiologyClass 11All
What are sclereids and what is their function in plants
Sclereids are a type of sclerenchyma cell that provides mechanical support and protection to plant tissues. Unlike the elongated fibers, sclereids are typically short, irregularly shaped cells with extremely thick, lignified secondary walls that make them very hard and rigid. They are found in various plant parts including seed coats (providing hardness), nutshells, pulp of fruits like pears (causing the gritty texture), and leaf tissues. Sclereids protect seeds, deter herbiv
- BiologyClass 11All
What is lateral meristem and how does it differ from apical meristem?
Lateral meristem is a type of meristematic tissue located along the sides of stems and roots, responsible for increasing the girth or thickness of plant organs (secondary growth). The two main types are vascular cambium (produces secondary xylem and phloem) and cork cambium (produces protective cork tissue). Unlike apical meristems that enable vertical growth at shoot and root tips, lateral meristems facilitate horizontal expansion. This secondary growth is characteristic of
- BiologyClass 11All
How many types of cells constitute phloem and what are they?
Phloem consists of four main types of cells: Sieve tube elements: The primary conducting cells that transport sugars and organic nutrients. They are elongated, living cells arranged end-to-end with perforated end walls called sieve plates. Companion cells: Specialized parenchyma cells closely associated with sieve tube elements, providing metabolic support and controlling their function. They have den
- BiologyClass 11All
What is the cavity found in vascular bundles of monocot stems called?
The cavity found in vascular bundles of monocot stems is called a lysigenous cavity or protoxylem lacuna. This cavity forms through the breakdown and dissolution of the first-formed xylem vessels (protoxylem) as the stem matures. As the plant grows and secondary xylem develops, these early-formed vessels become stretched and eventually disintegrate, leaving behind an empty space. This characteristic feature is commonly observed in monocot stems like maize, wh
- BiologyClass 11All
Name two modified types of parenchyma and their functions
Two important modified types of parenchyma are: Chlorenchyma (Chloroplast-containing parenchyma): Contains abundant chloroplasts for photosynthesis Found in leaves (mesophyll), young stems, and other green plant parts Responsible for producing sugars and oxygen through photosynthesis Essential for the plant's energy production and food manufacturing Well-developed intercellular spaces for gas exchange </u
- BiologyClass 11All
Who is considered the father of plant anatomy?
Nehemiah Grew is widely recognized as the "father of plant anatomy." This English physician and botanist made groundbreaking contributions to plant science in the 17th century through his detailed microscopic observations of plant structures. His pioneering work, published in "The Anatomy of Plants" (1682), provided the first comprehensive descriptions of plant tissues, cells, and their arrangements. Grew's meticulous illustrations and observations laid the foundation for modern plant anatomy
- BiologyClass 11All
What is lateral meristem and what type of growth does it produce?
Lateral meristem is a type of secondary meristematic tissue located parallel to the sides of organs where it occurs, typically forming cylindrical layers in stems and roots. The two main types are vascular cambium (producing secondary xylem and phloem) and cork cambium or phellogen (producing cork tissue). Unlike apical meristems that cause primary growth (elongation), lateral meristems are responsible for secondary growth, which increases the girth or diameter of stems and roots. This growth
- BiologyClass 11All
What are modified types of parenchyma tissue?
Two important modified types of parenchyma include chlorenchyma and aerenchyma. Chlorenchyma consists of parenchyma cells containing numerous chloroplasts, specializing in photosynthesis. These cells are abundant in leaves and green stems, where they capture light energy and convert it into chemical energy. Aerenchyma is parenchyma tissue with large air spaces or lacunae between cells, facilitating gas exchange and providing buoyancy. This tissue is particularly well-developed in aquatic and
- BiologyClass 11All
What are the three most common types of collenchyma?
The three most common types of collenchyma, classified based on the pattern of cell wall thickening, are: (1) Angular collenchyma, where thickening occurs at the corners where cells meet, commonly found in stems of many herbaceous plants; (2) Lamellar (plate) collenchyma, characterized by thickening on tangential walls (walls parallel to the surface), often seen in stems of some dicots; and (3) Lacunar collenchyma, which has thickening around intercellular spaces, providing flexibility while
- BiologyClass 11All
How many types of cells constitute phloem tissue?
Phloem tissue is composed of four main types of cells, each serving distinct functions. Sieve tube elements are the primary conducting cells that transport organic nutrients throughout the plant. Companion cells are closely associated with sieve tube elements, providing metabolic support and helping regulate transport. Phloem parenchyma cells store nutrients and assist in lateral transport of materials. Phloem fibers provide mechanical strength and support to the phloem tissue. Together, thes
- BiologyClass 11All
What are sclereids and what functions do they serve?
Sclereids are a type of sclerenchyma cell characterized by thick, heavily lignified cell walls and a relatively short, irregular shape. Unlike fibers (the other type of sclerenchyma), sclereids are typically isodiametric or branched and occur in various forms including stone cells, astrosclereids, and macrosclereids. These dead cells at maturity provide mechanical support and protection to plant tissues. Sclereids are responsible for the gritty texture in pears, the hardness of seed coats, an
- BiologyClass 11All
What are the conducting tissues in plants and what do they transport?
Plants have two main conducting tissues: xylem and phloem. Xylem is responsible for transporting water and dissolved minerals from the roots upward to all parts of the plant. It consists of specialized cells including tracheids and vessel elements that form continuous tubes for efficient water conduction. Phloem, on the other hand, transports organic nutrients, particularly sugars produced during photosynthesis, from leaves to other plant parts where they're needed for growth and storage. The
- BiologyClass 11All
What is promeristem and what role does it play in plant growth?
Promeristem is the earliest, most primitive form of meristematic tissue found at the extreme tips of roots and shoots. It consists of actively dividing, self-perpetuating initial cells that give rise to all other meristematic tissues. The promeristem maintains a constant supply of undifferentiated cells while simultaneously producing derivatives that develop into primary meristems (protoderm, ground meristem, and procambium). This tissue is characterized by small, isodiametric cells with thin
- BiologyClass 11All
What does the term "meristem" mean and who coined it?
The term "meristem" refers to regions of plant tissue containing undifferentiated cells capable of continuous division and growth. These specialized tissues are responsible for plant growth throughout the plant's lifetime. The term was coined by Carl Wilhelm von Nägeli, a Swiss botanist, in 1858. Meristems are essential for both primary growth (increase in length) and secondary growth (increase in girth) in plants. They remain perpetually embryonic, producing new cells that differentiate
- BiologyClass 11All
What is plant anatomy and why is it important to study?
Plant anatomy is the study of the internal structure of plants, including their tissues, cells, and organs. This scientific field examines how different plant parts are organized at the microscopic and macroscopic levels. Studying plant anatomy is crucial for understanding how plants function, grow, and adapt to their environments. It helps botanists, agriculturalists, and researchers identify plant species, improve crop yields, develop disease-resistant varieties, and understand evolutionary
- BiologyClass 11All
What is spring wood and why is it called that?
Spring wood, also known as early wood, is the wood formed during the spring and early summer growing season when environmental conditions are optimal for growth. This type of wood is characterized by: Large vessel diameter: Cells are wider with larger lumens for efficient water conduction Thin cell walls: Less lignification compared to late wood Light color: Appears lighter
- BiologyClass 11All
Give shape of guard cells in dicotyledonous plants.
Guard cells in dicotyledonous plants are kidney-shaped (or bean-shaped). Their unique structure, with: Thicker inner (ventral) walls Thinner outer (dorsal) walls Radial arrangement of cellulose microfibrils ...enables the opening and closing of stomatal pores through changes in turgor pressure. Contrast: In monocots (
- BiologyClass 11All
What is the membrane of vacuole called?
The membrane surrounding the vacuole is called the tonoplast. This selectively permeable membrane regulates the movement of ions and molecules between the cytoplasm and the vacuolar sap, maintaining turgor pressure and cellular homeostasis.
- BiologyClass 11All
Explain plasmodesmata.
Plasmodesmata (singular: plasmodesma) are microscopic protoplasmic connections that traverse the cell walls of adjacent plant cells. These channels facilitate intercellular communication and transport by creating a continuous cytoplasmic network called the symplast. Plasmodesmata allow the passage of: Water Ions Small molecules Regulatory proteins and RNA </u
- BiologyClass 11All
Write short notes on the following:
(a) Lateral meristems(b) Vessels(c) Subsidiary cells(d) Ground tissue Solution: (a) LATERAL MERISTEMS: Definition: Lateral meristems are cylindrical meristems located in the mature regions of roots and stems, responsible for secondary growth (increase in girth). Types: <ol