Tag: biology

Muscles have two major proteins actin and myosin. These are mostly contractile proteins. The energy from the hydrolysis of ATP by myosin head is directly used in the power stroke i.e., flexing of myosin head during muscular contraction. ATP is also used during muscle relaxation in the absence of ATP the myosin head will continue to bind with actin head and the muscle fibre shall remain contracted. So, the correct answer is option C.

Epithelial tissues are meant for covering and protecting the body, organs and cavities. They are not involved in body movements.
Bones form the framework of the body. They are hard and rigid. To carry out body movement property of contraction and relaxation is necessary. But bones can not contract.
Tendon is a tough fibrous connective tissue, which connects muscle to bone. Tendon does not have the property of contraction and relaxation. The ligament is a fibrous connective tissue, which connects bone to another bone. It is flexible but is not present throughout the body to carry out body movement.
Muscular tissues possess the property of contraction and relaxation. They are attached to bones. With the help of bones, muscular tissue carries out body movement. Therefore, option A is correct. 

Epithelial tissue is meant for covering and protecting the body, organs and cavities. They do not possess the property of contraction and relaxation. 
Connective tissue connects, supports and separates the organs in the body. These are present in different forms as fluid, jelly-like rigid, hard forms. 
Nervous tissue is meant for rapid transmission of the signals from one place to another. These tissues do not contract or relax.

Sarcoplasm is the cytoplasm of muscle cells or myocytes. Large amounts of glycosomes and significant amounts of myoglobin are usually found in the sarcoplasm.

Muscle tissue helps in locomotion and provides a structural framework to  the body. These have contractile proteins for contraction and relaxation. It controls voluntary and involuntary actions. It is separated into three distinct categories, smooth muscle, skeletal muscle and cardiac muscle. So, the correct answer is option C.

During embryonic development, the cells are pluripotent, meaning they have the capability to develop and differentiate into almost all cell types including muscle cells. Precisely, muscle cells are formed from the mesoderm of the embryo. So, the correct answer is ‘Embryonic development’.

Muscular tissue provides a structural framework to the body along with connective tissue. It has immense potential to contract as they have major contractile proteins like actin and myosin. The muscle contraction requires ATP which hydrolyses to ADP and inorganic phosphate to allow the overlap of the contractile proteins during muscle contraction. The calcium ions released by the sarcoplasmic reticulum acts as a cofactor to activate the contractile proteins.

Muscle tissue is the longest group of cells in the human body. These provide the structural framework to the body. They have contractile proteins which, contracts and relax to provide easy and flexible movements. Therefore, the correct answer is option B.

• Sarcoplasmic reticulum is similar to endoplasmic reticulum present in other cells. It is present in sarcoplasm (cytoplasm of the muscle cell) of the muscle fiber (muscle cell).
• The main function of the Sarcoplasmic reticulum is to store calcium ions (Ca2+).
• When nerve signal reaches the neuromuscular junction it triggers the release of calcium from sarcoplasmic reticulum which in turn facilitates muscle contraction by binding to troponin.
  
• Hence the organelle regulates the muscle contraction during internal movements is sarcoplasmic reticulum.
• So, the correct answer is'Sarcoplasmic reticulum'.

Actin is the thin filament which is present in the muscles. Myosin is the thicker filaments in the muscles. The tropomyosin is the regulatory protein which is present in the grooves of the actin filament. This is the regulatory protein which helps in the contraction and relaxation of the myosin bridge. These proteins are the structural units of the muscle fibres and help in the contraction and relaxation of muscles to allow internal movement of the involuntary muscles.