Anatomy of Flowering Plants Test - 69

So, the correct option is B.

Vascular cambium is the lateral meristem of plants. It is the secondary meristem that results in increase in the girth of plant. It forms secondary xylem called wood and secondary phloem.

• The flow chart illustrates the structural organisation or level of organisation in an organism.
• A is cell- structural and functional unit of life.
• B is a tissue- group of cells form tissues.
• C is an organ- similar tissues come together to form a specific organ.
• D is an organ system- organs combine to form differetn systems in an organism.
• E is an organism- different organ systems form an organism.
• The correct answer is OPTION A.

Amphivasal vascular bundle: one in which the phloem is surrounded by xylem. Although collateral bundles are most common in seed plants, a number of monocot species have amphivasal bundles instead or have amphicribral ones (in which phloem surrounds xylem).

So, the correct answer is "Centrally located phloem is surrounded by xylem".

• Xylem contains many different types of cells and is a heterogeneous tissue. The cells have different characteristics hence it cannot be concluded that its Xylem.
  
• Meristematic cells have thin cell walls and large prominent nucleus with no vacuoles. these are not permanent tissues and can undergo differentiation to form different kinds of cells.
  
• Parenchyma cells are living cells which have protoplasm and then cell walls and are soft so as to provide flexibility to the organs.
  
• Sclerenchyma cells have very thick cell walls which are lignified and they almost have no lumen hence protoplasm is absent in them. They are dead tissues and their function is only in mechanical support.
  

The semilunar valves are present inbetween the aorta and the left ventricle (aortic semilunar valve) and between the right ventricle and the pulmonary artery (pulmonary semilunar valve). The aortic semilunar valve functions to pevent backflow of blood into the ventricle. Damage to chordae tendinae of the aortic semilunar valve will therefore cause backflow of blood to the left ventricle. The first heart sound is produced by the closure of the mitral and the tricuspid valve, that are the atrioventricular valves. 

Intercalary meristem is present at internodes or stem locales between the spots at which leaves connect and leaf bases, particularly of specific monocotyledons, e.g. grasses.

Xylem comprises of vessels, tracheids, xylem parenchyma, and restricted xylem strands.  the vessel is Y-molded with bigger two round set metaxylem vessels shaping the arms and littler yearly or winding protoxylem vessels, framing the base.