Important Questions Class 11 Biology

Structural Organization in Animals Important Questions Short Answer Type

Question 1. What is the function of the transitional epithelium in the formation of the surface layer of the urinary bladder? 

Answer: The transitional epithelium is extremely stretchable, and it prevents the urinary bladder from being torn apart even when it is completely filled with urine. It goes through a significant amount of expansion in order to accommodate the maximum amount of urine.

Question 2.Identify and categorize the different types of muscular tissue.

Answer:  Muscular tissues can be divided into two broad categories based on the cytologic characteristics of the tissues.

They are as follows:

Muscles that are striated and those that are not.

Striated muscle cells, on the other hand, can be further subdivided into two categories: skeletal muscle cells and cardiac muscle cells.

As a result, they can be divided into three categories:

skeletal and voluntary muscle fibers that are striped or striped-like.

Muscle fibers that are not striated or unstriped, are plain or smooth, and are involuntary.

Cardiac muscle fibers are striated and involuntary in nature.

The most important function of hemoglobin is to transport oxygen throughout the body.

Question 3: What are the functions of hemoglobin ?

Answer: The following are the functions of hemoglobin:

In order for oxygen to be transported from the lungs to the tissues in the form of oxyhaemoglobin, it is required. Each molecule of hemoglobin transports approximately 1.33 ml of oxygen.

It is critical in the transport of CO2 from tissue to the lungs in the form of carbaminohemoglobin, which is produced by the liver. The hemoglobin is responsible for transporting approximately 23% of CO2 back to the heart and lungs.

It acts as a buffer and regulates the blood reactions by maintaining a constant pH level in the bloodstream.

Question 4:Describe the general characteristics of epithelial tissue 

Answer: Cells of various types and shapes are tightly packed together to form the lining membranes of several organs, including the intestines.

Intercellular cementing substance and close vascular connective tissues support the cells of the epithelial membrane, which is arranged in one or more layers on top of a thin non-cellular basement membrane. These cells are also supported by intercellular cementing substances and close vascular connective tissues.

The basement membrane is made up of protein fibers that are interspersed throughout a polysaccharide matrix to form the structure. The matrix is produced by the connective tissue that lies beneath the skin.

Mucoprotein, which contains hyaluronic acid and calcium salts, acts as a cement between the cells, holding them together.

Question 5: Describe what oligodendrocytes are in detail. What exactly are their functions?

Answer: Oligodendrocytes are a type of neuroglia cell that is responsible for holding the neurons in their proper positions in the nervous system. As a result, when Schwann cells are absent from the central nervous system, the myelin sheath is formed by spiraling around the nerve fibers and wrapping around themselves.

Question 6: Why does oedema occur in people who have a protein deficiency in their diet? 

Answer: In response to the question, albumin and globulin proteins are required for the retention of water in the blood plasma due to their osmotic effects. A protein deficiency in the diet causes the blood plasma to become dehydrated, which causes water to be filtered out of the blood and into tissues, resulting in the swelling of the hands and feet.

Question 7:Identify the specific tissue that forms the outermost exposed surface of the human skin in response to . Identify any two advantages of having this tissue available.

Answer: Keratinised squamous epithelium is the correct answer to the question. In addition, it contains an insoluble protein known as keratin, which is impervious to water and thus helps to prevent water loss. It also serves to protect the skin against mechanical pressure, friction, injury, and water loss, amongst other things.

Question 8: Write a brief note on the process of erythropoiesis.

Answer: The formation of new erythrocytes is referred to as erythropoiesis, and it takes place from the hematopoietic tissue (blood vessel). It is the liver and spleen that contain hemopoietic tissue in the young fetus, whereas the bone marrow of long bones contains hemopoietic tissue in adults.

Every minute, millions of red blood cells (RBCs) are synthesized by the hematopoietic tissue to replace worn-out erythrocytes. This process is aided by erythropoietin, a glycoprotein produced by renal tissue in response to the release of ACTH. Anemia, megaloblastic anemia, and pernicious anemia, among other things, are caused by a lack of iron, folic acid, and vitamin B in the diet.

Question 9: What methods are used to keep blood from clotting in the blood banks?The various anticoagulants are popular in blood banks, so that’s why they exist.

Answer: Sodium oxalate, sodium citrate, and EDTA (Ethylene diamine tetraacetic acid) are examples of anticoagulants that work by removing calcium ions from the bloodstream.

In addition, the removal of free calcium ions from the whole blood can help to prevent clotting because this metallic ion is required at several stages of the coagulation mechanism.

Question 10: What is the process by which saltatory conduction occurs along a nerve fiber?

Saltatory conduction is the term used to describe the conduction of an impulse in conjunction with a myelinated nerve fiber. Due to the ionic changes and subsequent depolarisation occurring only at the nodes of Ranvier that are not surrounded by myelin sheath, the action potential jumps from one node to the next in this manner.

Cell: The Unit of Life Important Extra Questions Short Answer Type

Question 1: A cell’s function is the result of the sum of the activities and interactions of its constituent cells, according to the scientific theory of function. Comment.

Answer: Cells are the fundamental building blocks of all living things. Schleiden and Schwann discovered that all animals and plants are composed of cells, and that cells are the functional units that make up their bodies. Tissues are formed by cells, tissues are formed by organs, and organs are formed by organ systems. Organ systems are interconnected in order to carry out a specific function for that system as a whole. There are various types of cells in the body of an individual, each of which performs a specific function.The activities of an organism are the sum total of the coordinated activities and interactions of its constituent cells, and all of the cells in the body share the same genetic material as one another. Because all new cells in an organism develop from pre-existing cells, all cells contain DNA hereditary material or RNA, which is passed from one generation to the next through division of the cell.

As a result, each cell contains the same genetic information as the others and has the ability to give rise to a new individual. The cell’s ability to reproduce is referred to as totipotency.

Question 2:Unicellular organisms have a better chance of surviving than multicellular organisms, according to research. Why?

Answer: Division of labor: Some organisms are made up of only one cell, whereas others are made up of many cells (Amoeba, Paramecium, Chlamydomonas, etc.) Unicellular organisms are what we call these types of organisms. In these organisms, all of the essential life functions are carried out entirely within a single cell. Most organisms, on the other hand, are made up of a large number of cells.

These organisms are also quite large in stature. It is not possible for all of the cells in these multicellular organisms to carry out all of the essential functions of life. When compared to unicellular organisms, multicellular organisms have a distinct advantage because the cells in these organisms are more specialized in their roles in the course of life.

Some cells of the body in multicellular animals, such as humans, are responsible for the function of movement (muscle cells), while others are responsible for the functions of digestion and respiration, as well as waste removal from the body. A specific type of cell or a group of cells that perform only a few limited functions is known as a cell type.

Higher plants have cells that perform protective functions (epidermal cells), and cells that transport water, minerals, and food substances throughout the body (translocation cells) (xylem and phloem).

These cells would be capable of performing a variety of other tasks if they weren’t so specialized. Tissues are defined as a collection of cells that are similar in appearance and perform similar functions. Multicellular organisms find this system to be extremely advantageous. Because the cells of the body have divided the work, it is more efficient. The division of labour is the technical term for this. Consequently, all vital activities in an organism’s body are carried out in a coordinated manner as a result of this division of labour among the cells.

Question 3:Note the structure of the nucleus on a piece of paper.

Answer: The Nucleus’s Structure: The nucleus is one of the most important components of the cell, and it has a variety of functions. This organelle is referred to as the control center of the cell because it regulates the various metabolic activities that occur within the cell. The nucleus of the cell is found within the cytoplasm of the cell. In most cases, the nucleus is round, but in some cells, nuclei of various shapes can be observed.

It is surrounded by two porous membranes known as nuclear membranes, which are connected to the ER by a thin membrane called the endoplasmic reticulum. Nuclear membranes contain a liquid substance known as nucleoplasm, which is found within them. chromatin material is found in the nucleoplasm, which can be divided into two types: heterochromatin and euchromatin.

Question 4: Make a brief observation about the bacterial cell wall.

Answer: Bacterial cell walls are made of murein or peptidoglycan, which are both glycoproteins. It is made up of polysaccharides that are linked together by short amino acid chains. Lipopolysaccharide forms a protective coating around the cell wall of Gram-negative bacteria..It may be able to provide these cells with specific adhesion properties. It is responsible for determining the shape of the cell.