Test: Animal Tissues - 2

Red pigment of vertebrate blood is haemoglobin. Haemoglobin is a conjugated protein. It consists of a basic protein globin joined to a nonprotein group heme, hence the name haemoglobin. Heme is an iron-porphyrin ring. A mammalian haemoglobin molecule is a complex of 4 heme molecules joined with 4 globin molecules.

The kinesin, myosin and dynein proteins of skeletal muscle involve ATPase activity. This cause the contraction of skeletal muscles, propelling action of cillia and flagella and the intracellular transport of organelles.

Immunoglobulin A (IgA), as the principal antibody class in the secretions that bathe these mucosal surfaces, acts as an important first line of defence. IgA, also an important serum immunoglobulin, mediates a variety of protective functions through interaction with specific receptors and immune mediators. The importance of such protection is underlined by the fact that certain pathogens have evolved mechanisms to compromise IgA-mediated defence, providing an opportunity for more effective invasion. IgA function may also be perturbed in certain disease states, some of which are characterized by deposition of IgA in specific tissues. This review details current understanding of the roles played by IgA in both health and disease.

The medial rectus is an extraocular muscle that attaches to the side of the eye near the nose. It moves the eye inward toward the nose. The lateral rectus is an extraocular muscle that attaches to the side of the eye near the temple. It moves the eye outward.

Tissues can be categorized based on the cell types that are present. If a tissue contains only one cell type it is called a simple tissue. If a tissue contains more than one cell type it is a complex tissue.
(i) Simple Tissues (made up of one cell type).
(ii) Complex Tissue (made up of more than one cell type)

The respiratory or gas - exchange surface consists of millions of small sacs, or alveoli, lined by a simple squamous  epithelium. This epithelium is exceedingly thin to facilitate diffusion  of oxygen and CO2. The alveolar walls also contain cuboidal surfactant - secreting cells.

The main characteristic of epithelial tissues is cells can be subjected to rapid division. Epithelial tissue is abundant all over the body. They form the covering of all surfaces of the body, line cavities of the body, and hollow organs and are the main tissue in glands.

The pH of the  extracellular fluid, including the blood plasma, is normally tightly regulated between  7.32 and 7.42 , by the chemical buffers, the respiratory system, and the renal system. 
So, the correct answer is Alkaline.

B is the correct option.Hyaline cartilage is a type of connective tissue found in areas such as the nose, ears, and trachea of the human body. The word hyaline means “glass-like”, and hyaline cartilage is a glossy, greyish-white tissue with a uniform appearance.

All the above is the correct opt.

• It causes any cell to commit suicide.
• It enzymes digest the cell itself.
• it enzymes kill surrounding cells

B is the correct option.Osteocytes derive from osteoblasts, or bone-forming cells, and are essentially osteoblasts surrounded by the products they secreted. Cytoplasmic processes of the osteocyte extend away from the cell toward other osteocytes in small channels called canaliculi.

The correct answer is B as Volkmann's canals are small channels in bone that transmit blood vessels from the periosteum into the bone and that lie perpendicular to and communicate with the Haversian canals. It is named after Volkmann Alfred Wilhelm. It is only found in bones of mammals. Hence, option C is correct.