CBSE Questions for Class 9 Biology Tissues Quiz 11 - MCQExams.com

• Eosinophils: These cells play important role in immunity and allergic reactions.
• Basophils: These cells secrete histamine, serotonin and heparin.
• Neutrophils: These cells perform phagocytosis.

• Lymphocytes: These cells produce antibodies.
• Monocytes: These cells are phagocytic.

• The contractile regulatory proteins that mask and unmask active sites in the sarcomere are troponin and tropomyosin. 
  
• The two tropomyosin filaments run close to the actin filaments throughout its length.
  
• The troponin units are distributed throughout the length of tropomyosin filaments and mask the active binding sites for myosin.
  
• During muscle contraction, the increased calcium ion levels lead to their binding to a subunit of troponin and unmasking the active sites for myosin filaments.
  

1. The various complex proteins involved in muscle contraction are actin and myosin along with troponin and tropomyosin.
2. Thyroid hormones are triiodothyronine (T3) and Tetraiodothyronine (T4) which help in regulating the Basal Metabolic Rate of the body.
3. Pepsin is a protein digestive enzymes secreted in the stomach but prolactin is a hormone secreted by the anterior pituitary.
4. Secretin is a polypeptide hormone which functions to regulate pH of the stomach by inhibiting gastric acid secretion but rhodopsin is the visual pigment present in our eyes and a G protein-coupled-receptor.

1. Cartilage is made up of specialized cells called chondrocytes. These chondrocytes produce large amounts of extracellular matrix composed of collagen fibers, proteoglycan, and elastin fibers.
   
2. Adipose tissue is loose connective tissue composed of fat cells known as adipocytes. Adipocytes contain lipid droplets of stored triglycerides.
   
3. The different kinds of cells present in areolar connective tissue are macrophages, mast cells, adipocytes, fibroblasts and plasma cells.
4. Glandular epithelium covers the endocrine and exocrine glands of the body. The main function is secretion.

A. New born babies

Reason: Infants have fetal hemoglobin, where has more affinity for oxygen than the hemoglobin found in adults. So, due to more affinity, oxygen binding will also be strong. The amount of oxygen released by RBC at the tissue level is deceased. So in order to compensate for the decreased oxygen availability the number of RBCs is increased.

• The bone is mainly composed of calcium and phosphorus. The bone is a hard connective tissue.

• The presence of mitochondria means that all cells are metabolically active and are capable of aerobic respiration.
• Since red blood cells lack cell organelles & nuclei at maturity aerobic respiration does not occur in them. 
• The rest of the given cells have nucleus & organelles in them. 

• Bone is a kind of specialised connective tissue.
• They support and protect the various organs of the body, produce RBC's and WBC's, store minerals, provide structure and support for the body, and enable mobility.
  

• Loose connective tissue is a category of connective tissue which includes areolar tissue, reticular tissue, and adipose tissue. 
• Loose connective tissue has cells and fibres loosely arranged in a semi-fluid ground substance, for example, areolar tissue present beneath the skin.
  
• It serves as a support framework for epithelium.
  
• It is found between the skin and muscles and connects the skin to the underlying muscles.
  

• Cardiac muscles : Branched, cylindrical, Involuntary, Uninucleated.
  
• Skeletal muscles : Unbranched, Cylindrical, Voluntary, Multinucleated.
  
• Smooth muscles : Fusiform, Involuntary, Uninucleated.
  

1. Xylem is a type of complex permanent tissue that is involved in the transport of water.
2. Phloem is another component of the vascular bundle that transports the food material from the leaves to the other parts.
3. The cell membrane is a selectively permeable structure that allows the passage of selected molecules.
4. Guttation is the phenomenon of the exudation of drops of xylem sap on the tips or edges of leaves of some vascular plants, such as grasses, and several fungi and it occurs due to the pressure existing within the xylem vessels known as root pressure.
5. The cell wall is the freely permeable outermost covering of plant cells.

• Smooth muscle fibers are unstriated/ unstriped means with no striations. And they are located in walls of hollow visceral organs, except the heart, appear spindle-shaped, and are also under involuntary control. 
• Skeletal muscle fibers are present in muscles which are attached to the skeleton. They show striated appearance and are under voluntary control. 
• So, the correct answer is 'False'