Tag: biology

1. sarcoplasmic reticulum is a specialized type of smooth ER that regulates the calcium ion concentration in the cytoplasm of striated muscle cells. 
   
3. sarcoplasmic reticulum  is a membrane-bound structure found within muscle is also known as endoplasmic reticulum of muscle. so option A is correct answer .

• The ‘A’ and ‘I’ bands are arranged alternately throughout the length of the myofibrils.
  
• In the centre of each ‘I’ band, there is an elastic fibre called ‘Z’ line which bisects it. The thin filaments are firmly attached to the ‘Z’ line. 
• The portion of the myofibril between two successive ‘Z’ lines is considered as the functional unit of contraction and is called sarcomere.
• Hence Sarcomere is the unit of contraction.
  

• Muscle is a  bundle of fibrous tissue in a body that has the ability to contract, producing movement in or maintaining the position of parts of the body.
  
• The total number of muscles in the human body comes in the range of 640-850.
  
• So,the correct answer is '640-850'

Movement is performed by muscular tissues. Every bone moves with the help of 2 muscles required to move it. 

•  Syncytial or syncytium is a multinucleated cell that can result from multiple cell fusions of uninuclear cells (i.e., cells with a single nucleus), which can result from multiple nuclear divisions without accompanying cytokinesis. 
• Syncytial is also referring to cells interconnected by the specialized membrane with gap junctions, as seen in the heart muscle cells and certain smooth muscle cells, which are synchronized electrically in an action potential. Hence, Condition of having a number of nuclei in a muscle fibre is syncytial.

Adulteration is a process of mixing undesirable and inferior materials in food. The material or substance which is added to food is called as adulterants. Generally, ghee is adultered with vanaspati. However, when ghee is adultered with coal tar dyes. This adulteration is detected by adding hydrochloric acid to the ghee. The appearance of crimson red colour indicates the adulteration of ghee with coal tar dye.

Adulteration is a process of mixing undesirable and inferior materials in food. The material or substance which is added to food is called as adulterants. The most common adulterant used in milk is water. The water adulteration in a milk can be detected by using lactometer. When water is added to milk, the density of the milk decreases and this is detected using lactometer.The reading below 1.026 in the lactometer indicates adulteration of milk with water. 

Oedema is also called dropsy and hydropsy. It is an abnormal accumulation of fluid in the interstitium, located beneath the skin and in the cavities of the body. It occurs due to poisoning by Argemone mexicana. Argemone mexicana seed oil is generally added as an adulterant into the edible oil.