CBSE Questions for Class 11 Medical Biology Structural Organisation In Animals Quiz 12 - MCQExams.com

• Annelids have highly coiled tubules called nephridia which are involved in the removal of waste. 
• The waste is discharged into the gut or the exterior through the nephridiopore. 
• The nephridia in some of the annelids are of three types i.e., the pharyngeal, integumentary, and septal nephridia.
• The septal and pharyngeal nephridia open into the gut and, thus, are called enteronephric types. 
• This helps to conserve maximum water through the process of reabsorption when waste passes through the gut.

• Muscle fatigue refers to a decrease in muscle force generated over time.
• Skeletal muscles are used to move the bones in the body and may get fatigued because of overexertion. 
• Overexertion such as intensive exercise results in depletion of oxygen levels in the muscles. So, the muscles shift temporarily to anaerobic metabolism to generate energy. This is done by the formation of lactic acid and energy. Accumulation of lactic acid in muscles leads to muscle fatigue.
• The cardiac muscles are resistant to fatigue as they contain large numbers of mitochondria (powerhouses of the cell), enabling continuous aerobic respiration and ATP production required for mechanical muscle contraction. The rate of contraction and relaxation in smooth muscles is very slow which consumes less ATP. Thus, smooth muscles also do not experience fatigue.

• The mouthparts of the cockroach are provided with taste receptors or chemoreceptors. 
• These are mainly confined to the tips of maxillary palps, labial palps, labium, and hypopharynx. 
• Campaniform sensilla is a class of mechanoreceptors found in the exoskeleton of insects and responds to stress and torsion of the same.
  
• Compound eyes are involved in vision, not taste.
  
• Cockroach legs have several tactile receptors on each leg that respond to touch.

A medullated nerve fiber is also called as myelinated nerve fiber. The nerve fibers, which are covered by the myelin sheath are called as medullated nerve fibers. Myelin sheath is derived from Schwann cells. Myelin sheath is made up of alternate concentric layers of lipids and proteins. Myelinated nerve fiber also shows the presence of neurolemma. It covers the nerve fiber.

So, the correct answer is 'Both A and B'

• Blood is a fluid connective tissue, which has plasma (liquid) as its matrix and red blood cells (RBC), white blood cells (WBC), platelets as cells.  
• Areolar tissue is found in between skin and muscles, around blood vessels, neurons, and also in the bone marrow. Being soft and loose they carry out the function of supporting internal organs and repairing of tissues by filling spaces. 
• Striated muscle tissues are tissues, which have pattern of repeating sarcomere. A sarcomere is the basic unit of muscle. Striated skeletal muscle tissues are attached to bones and are voluntarily controlled, i.e., controlled by will.  
• Adipose tissue is a type of connective tissue in which fat is stored. They are generally located below the skin. The layer of adipose tissue beneath the skin is known as the subcutaneous layer, which acts as an insulator. 
• Cartilage is a type of connective tissue in which solid matrix is made of protein and sugars. Cartilage is present on the joint surface and makes it smooth.
• Squamous epithelium cells are thin and flat and form a delicate lining. In skin squamous epithelium cells are arranged in many layers hence, called stratified squamous epithelium. It protects the body.