Test: Connective Tissue- 4 - NEET MCQ

When there is an injury and blood is shed, the platelets disintegrate and liberate thromboplastin or factor III. Certain amount of thromboplastin is also derived from the damaged tissues of the injured locality.
Thromboplastin converts prothrombin into thrombin with the help of calcium ions and thrombin interacts with fibrinogen forming fibrin. This is clot.
Calcium is the Factor IV and it acts as a co-factor in the coagulation process.
Thus, the correct answer is option (D).

Pinna is composed of a thin plate of yellow elastic cartilage, which is covered with integument and connected to the surrounding parts by ligaments and muscles. Hence, option C is correct answer.

Platelets are a source of thromboplastin. Thromboplastin is a plasma protein aiding blood coagulation through catalyzing the conversion of prothrombin to thrombin. It is a complex enzyme that is found in the brain, lung, and other tissues and especially in blood platelets and that functions in the conversion of prothrombin to thrombin in the clotting of blood, called as thrombokinase.

Connective tissue is one of the four basic types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesoderm of the embryo.
Connective tissue is the most abundant and widely distributed tissue of the body. Three components are present in the connective tissues. These are matrix, cells, and fibers.
The matrix (ground substance) is mainly a mixture of carbohydrates and proteins to fix the body water and the collagen fibers in the intercellular spaces.
So, the answer is B.

Keratin is a family of fibrous structural proteins. It is the protein that protects epithelial cells from damage or stress that has potential to kill the cell.

Elastin is a highly elastic protein in connective tissue and allows many tissues in the body to resume their shape after stretching or contracting.

Dextrins are a group of low-molecular-weight carbohydrates produced by the hydrolysis of starch or glycogen. 

Collagen is the main structural protein in the extracellular space in the various connective tissues in animals.

As Dextrin is a carbohydrate, whereas rest others are proteins, hence it is unrelated. Hence, option C is correct.

WBC are also known as leucocytes. Their number is much less than RBC. It provides defence mechanism to the body against infection. They are formed in bone marrow and their life span is also very short which is usually less than 10 days, although it differs for each leucocyte. Hence, option B is correct.

A ligament is a short band of tough fibrous connective tissue composed mainly of long, stringy collagen fibres. Ligaments connect bones to other bones to form a joint. Some ligaments limit the mobility of articulations, or prevent certain movements altogether.

Prothrombin is a component of blood which helps in blood coagulation. It is mainly synthesized by the liver. Prothrombin of blood plasma is converted to thrombin in the presence of thromboplastin and calcium ion during blood clotting. Albumin is a globular protein, produced by the liver. It occurs in blood plasma and is the most abundant blood protein in mammals. Albumin functions primarily as a carrier protein for steroids, fatty acids, and thyroid hormones in the blood and plays a major role in stabilizing extracellular fluid volume by contributing to oncotic pressure.
Fibrinogens are large, soluble and complex glycoproteins in vertebrates, that helps in the formation of blood clots. It is synthesized in the liver by the hepatocytes. The fibrinogen molecule is converted by thrombin into fibrin during blood clot formation
So, the correct answer is 'Liver'.

Cartilage is regenerated from undifferentiated cartilage precursor cells of the perichondrium. Therefore, articular cartilage and fibrocartilage, which do not possess a perichondrium, cannot regenerate.

Mast cells are occur in connective tissue like blood they release histamine to dilate the blood vessels which makes them permeable for entry of WBC. They rush to site of infections. Connetive tissue are surrounding blood cells, smooth muscles, mucous etc.

Blood is considered a connective tissue because it has a matrix. The living cell types are red blood cells, also called erythrocytes, and white blood cells, also called leukocytes. The fluid portion of whole blood, its matrix, is commonly called plasma.

Hemoglobin bound iron remains in the ferrous (Fe2+) state during oxygen binding, transport and release. When hemoglobin bound iron is oxidized to ferric (Fe3+) iron, it cannot transport oxygen. 

So, the correct answer is 'Fe2+'

White fibrous connective tissue are of 2 types:
1) Regular
2) Irregular
Tendons belong to dense regular white fibrous connective tissue as it is made up of collagen fibres and having no intercellular spaces arranged in regular manner containing macrophage nd mast cells in abundant amount.

Correct Answer :- a

Explanation : Loose connective tissue (LCT), also called areolar tissue, belongs to the category of connective tissue proper. Its cellular content is highly abundant and varied. The ECM is composed of a moderate amount of ground substance and two main types of protein fibers: elastic and reticular fibers.

Percentage of hemoglobin in RBCs is around 34%.in mammals the proteins make 96% of the RBCs in dry content and around 34% of the total content. Hemoglobin molecule can bind to four oxygen molecule.

Reticulocytes are immature red blood cells, typically composing about 1% of the red blood cells in the human body. In the process of erythropoiesis (red blood cell formation), reticulocytes develop and mature in the bone marrow and then circulate for about a day in the blood stream before developing into mature red blood cells. Like mature red blood cells, in mammals, reticulocytes do not have a cell nucleus.
So, the correct answer is 'No nucleus'.

During the process of blood clotting, platelets release thromboplastin which converts prothrombin into thrombin. This thrombin in the presence of calcium ions is responsible for conversion of fibrinogen into insoluble fibrin, thus forming a clot

So, the correct answer is 'Prothrombin'

Hyaline cartilage is cartilage that is hyaline (transparent). It is found on many joint surfaces. It is pearly bluish in color with firm consistency and has a considerable amount of collagen. It contains no nerves or blood vessels and its structure is relatively simple
So, the correct answer is 'Hyaline'

The RBC count is the total number of red blood cells per cubic millimeter of blood. In response to hypoxia, the hormone erythropoietin, secreted by the kidneys, stimulates the bone marrow to produce red blood cells. The formation of red blood cells is known as erythropoiesis. Normal red blood cells values at various ages are:
Newborns: 4.8 - 7.2 million,
Adults: (males): 4.6 - 6.0 million,
Females: 4.2 - 5.0 million,
Pregnancy: slightly lower than normal adult values and
Children: 3.8 – 5.5 million.
Thus, the correct answer is option B.

Option ( a)  8000  is ✔correct answer. 

Explanation :- White blood cells (WBCs), also called leukocytes, are an important part of the immune system. These cells help fight infections by attacking bacteria, viruses and germs that invade the body. White Blood Cells originate in the bone marrow, but circulates throughout the bloodstream. Number of WBCs per mm³ of human blood is approximately 8000.

Hence, option A is correct.