Answer: Option C. -> Intercalated discs
:
C
Intercalated disksare cross-bands that separate the opposing ends of cardiac muscle cells. These bands are the result of elaborate junctions of membranes at the cell's boundary. They help to hold adjacent cells together and transmit the force of contraction from cell to cell. Intercalated discs at some fusion points allow the cells to contract as a unit, i.e., when one cell receives a signal to contract, its neighbours are also stimulated to contract.
Anintervertebral diskacts as shock absorber between each of the vertebrae in the spinal column by keeping the vertebrae separated when there is impact from activity.
Intervertebral foramen is an opening between vertebrae through which nerves leave the spine and extend to other parts of the body.
Interneuron isa neuron which transmits impulses between other neurons, especially as part of a reflex arc.

Answer: Option C. -> Muscle tissue--protection from pathogens
:
C
Muscle will not give protection from pathogens.The mainfunctionof themuscularsystem is movement.
Endothelium is a type ofepithelium that linesthe interior surface of blood capillaries.
Adipose tissue, or fat, is an anatomical term for loose connectivetissuecomposed of adipocytes. Its main role is to store energy in the form of fat, although it also cushions and insulates the body.The cells innervous tissuethat generate andconduct impulsesare called neurons or nerve cells.​​​​​​​

Answer: Option C. -> Adherens junction
:
C
Tight junctions help to stop substances from leaking across a tissue. Gap junctions facilitate the cells to communicate with each other by connecting the cytoplasm of adjoining cells, for rapid transfer of ions, small molecules and sometimes big molecules. Adherens junctionhelp in cementing or packing the neighbouring cells together and are formed by a protein called Cadherin.Desmosomesare intercellular junctions that connect intermediate filaments to the cell surface and mediate strong cell-cell adhesion.

Answer: Option B. -> Falsely-stratified single layer of epithelial
:
B
Apseudostratified epitheliumis a type ofepitheliumthat, though comprising only a single layer of cells, has its cell nuclei positioned in a manner suggestive of stratifiedepithelia.

Answer: Option A. -> Both assertion and reason are true and the reason is the correct explanation for the assertion.
:
A
Body of ananimalis formed of several kinds of cells. There are about 200 different types of specialized cells in the human body. The cells of one or more kinds are arranged together in a characteristic manner and cooperate to perform a specific role. Such a group of cells is called a tissue.Specialization of cells into a tissue, organ and organ system is advantageous for an organism. It increases the operational efficiency through division of labour which avoids duplication of work.

Answer: Option C. -> Mucous tissue
:
C
Mucous connective tissue that is found in the vitreous humour of eye and umbilical cord of newborns and is also called as Wharton's jelly. The matrix is gelatinous and slippery due to presence of mucopolysaccharides and semi solids.

Answer: Option D. -> Ostia
:
D
Blood vascular system of cockroach is an open type. Blood vessels are poorly developed and open into space (haemocoel). Visceral organs located in the haemocoel are bathed in blood (haemolymph). The haemolymph is composed of colourless plasma and haemocytes. Heart of cockroach consists of elongated muscular tube lying along mid dorsal line of thorax and abdomen. It is differentiated into funnel shaped chambers with ostia on either side. Blood from sinuses enter heart through ostia and is pumped anteriorly to sinuses again.

Answer: Option C. -> Mesoderm
:
C
Thegerm layersdevelop early inembryoniclife, through the process of gastrulation. During gastrulation, a hollow cluster of cells called a blastula reorganizes into 3 primarygerm layers: an innerlayer called endoderm, a middle layer called mesoderm and an outerlayer, called ectoderm.
Connective tissue arises from mesoderm.

Answer: Option A. -> Ligament
:
A
The connective tissue with regular fibers and thick matrix which connects bone to bone is Ligament. They keep the bones intact and helps it in movement. They also serve as cushioning pads for the bone ends and joints.A tendon is a fibrous connective tissue which attaches muscle tobone.Tendonsmay also attach muscles to structures such as the eyeball.

Answer: Option B. -> Stapedius – the smallest muscle in the hand
:
B
Thestapediusis the smallest skeletal musclein the humanbody. At just over one millimeter in length, its purpose is to stabilize the smallest bone in the body, the stapes.