CBSE Questions for Class 11 Medical Biology Anatomy Of Flowering Plants Quiz 3 - MCQExams.com

• When there are more than four xylem arms, it is called polyarch condition. Monocot roots are usually polyarch. 
• Bundles of phloem appear alternately with the xylem arms. The xylem contains many lignified cells in older portions of the root. The phloem has cells with thin, unlignified cell walls.

• The innermost cortical layer is called endodermis. Its cells are barrel-shaped and are closely packed. Many cells get suberized on their radial and inner walls. These thickenings are called casparian stripes. 
• Between xylem and phloem elements, parenchyma cells are present constituting conjunctive tissue, which later becomes a secondary meristem. 
• Xylem and phloem patches are in equal numbers and alternate with each other. Xylem or phloem patches are usually four in number. In the xylem, the protoxylem elements face pericycle. Pith is very small, with closely packed parenchyma cells.

• Plant tissues may be meristematic or permanent. 
• Permanent tissues may be simple, made up of a single type of cells (parenchyma, collenchyma and sclerenchyma) or complex, made up of cells of more than one type (xylem and phloem). Parenchyma cells are thin walled and have intercellular spaces. Collenchyma cells have thickenings of cellulose and pectin at the corners.
• Meristematic tissues are made up of continuously dividing cells and permanent tissues are made of non-dividing cells. They include Apical, intercalary and lateral meristems. One important characteristic of the rapidly dividing cell is the lack of vacuoles.
  
• Hence 'C' is the right option because apical and intercalary meristems are not permanent tissues.

Slide 2 shows the stages of the meiosis and it can take place only in the reproductive parts of the plant. There are two phases of meiosis- meiosis, which are being observed in slide 2 as there is the formation of four cells from a single cell. The flower is the reproductive part of the plant and it undergoes meiotic division during the formation of the male and the female gametes.

Thus, the correct option is C.

• Simple permanent tissues are a group of cells with the same origin, structure and function.
•  Parenchyma, collenchyma, and sclerenchyma are simple tissue which coordinates to perform a similar function.

• Heart of mammals and birds is four-chambered with complete separation of oxygenated and deoxygenated blood. During a cardiac cycle, the right atrium receives deoxygenated blood while the left atrium receives oxygenated blood. 

• Tracheids and vessels are nonliving conducting elements of vascular plants. They are involved in the conduction of sap. from roots to aerial parts. Vessels are characteristic of angiosperms while tracheids are found in all vascular plants including pteridophytes, gymnosperms, and angiosperms.

• Tracheids are thick walled xylem cells that are involved in the transport of water.
• Sieve tubes and Companion cells are phloem cells.
• Sclereids are a type of dead sclerenchyma cells.

• Sclerenchyma fibres are ideal for obtaining fibres, which are useful for processing in the textile industry.
• Sclerenchyma fibres are predominantly long celled, with thick walls, small cavities and pointed ends. Jute and hemp fibres are formed of sclerenchyma. 
• Therefore, sclerenchyma fibres are commercially exploited to obtain hemp and jute.
•  Therefore, option A is correct. 

• Epiblema is a distinct epidermal cell located in rootlets of plants. 
• It is the outer part of most of the root hairs in the cells. 
• Muscle fibre, nerve fibre and skin are present in animals.
• Since epiblema is the only one that is present in plants, it is the odd one out.

• Secondary or lateral, meristems are found in all woody plants and some herbaceous ones.
• It consists of the vascular cambium and the cork cambium. 
• They produce secondary tissues from a ring of vascular cambium in stems and roots. 
• Hence, the cambium adds a grith to the lateral meristem.
• So, the correct answer is 'Adds to plant girth.

Phloem tissue helps to conduct the food made in the leaves to all other parts of the plant. It consists of sieve tubes, companion cells, phloem fibres, and phloem parenchyma cells.

The endodermis is the main and innermost layer of the cortex in land plants.

The epidermis is the single layer of cells, found on the outer layers in different parts of a plant,

The xylem is the vascular tissue, which is composed of primarily two types of non-living cells: Xylem consists of tracheids, vessels, and xylem parenchyma and xylem fibres. The cells have thick walls, but many of them are dead cells.

So the correct option is C.

• Lignin is a component of the cell walls of sclerenchymatous cells. 
• Two types of sclerenchyma cells exist - fibres and sclereids. Their walls consist of cellulose, hemicellulose, and lignin. 
• Sclerenchyma cells are the dead cells in plant tissues that play a vital role in providing mechanical support to the plants.
• Thus, the correct answer is option C.

Parenchyma, collenchyma, and sclerenchyma are called simple tissues. They are made up of similar kinds of cells. Vascular tissues are complex tissues as they are heterogeneous in nature with different types of cells. The main elements are the xylem, phloem and pericycle.

Thus, the correct option is B.

• The layer of cells outside the phloem meant for giving rise to the root branches is called the pericycle. The pericycle is a cylinder of parenchyma or sclerenchyma cells that lies just inside the endodermis and is the outermost part of the stele of plants. 
• Although it is composed of non-vascular parenchyma cells, it is still considered part of the vascular cylinder because it arises from the procambium as do the vascular tissues it surrounds.