Question

relate the following specific structural features to the function :
a) lignification of cell walls in sclerenchyma
b) Dark and light bands in striated muscles
c) Haversian system in bones

Answer 1

(a) In sclerenchyma tissue:- The cells of this tissue are dead. They are rigid, contain thick and lignified secondary walls. Their main function is to provide strength and support to parts of the plant.

(b) striated muscles also called skeletal muscles, when viewed under a microscope, skeletal muscle tissue has a striped or striated appearance. The striations are caused by the regular arrangement of contractile proteins (actin and myosin). These proteins helps in contraction and relaxation which results in locomotion.

(c) The haversian system in bones/channels are formed by concentric layers called lamellae. The haversian canals surround blood vessels and nerve cells throughout bones and communicate with bone cells (contained in spaces within the dense bone matrix called lacunae) through connections called canaliculi.

Answer 2

$<p style="color:cyan;font-family:cursive;background:black;font-size25px;"> (a) In sclerenchyma tissue:- The cellsof this tissue are dead. They are rigid, contain thick and lignified secondary walls. Their main function is to provide strength and support to parts of the plant.</p><p></p><p>(b) striated muscles also called skeletal muscles, when viewed under a microscope, skeletal muscle tissue has a striped or striated appearance. The striations are caused by the regular arrangement of contractile proteins (actin and myosin). These proteins helps in contraction and relaxation which results in locomotion.</p><p></p><p>(c) The haversian system in bones/channels are formed by concentric layers called lamellae. The haversian canals surround blood vessels and nerve cells throughout bones and communicate with bone cells (contained in spaces within the dense bone matrix called lacunae) through connections called canaliculi.$