Chapter wise questions of zoology:class XII

 Chapter wise Questions of zoology_ XII

1. Animal tissue:

1. List the functions of epithelial tissue.

2. What are the types of simple epithelium? Give one example and function of each type.

3. write about pseudostratified epithelium.

Ascariasis

It is a common intestinal disease caused by Round worm ( Ascaris lumbricoides). The worm lives in the intestine and causes a number of disorders.

Occurrence: It is a common disease found throughout world. However, more frequent in tropical countries. It is more common among children than in adults. It is most common in persons with unhygienic habits.

Causative organism: The causative organism is Ascaris lumbricoides.

Hepatitis: An introduction

Hepatitis is communicable disease caused by virus. In it there is an inflammation of the liver causing jaundice.

Hepatitis is one of the communicable pathogenic diseases as dangerous as that of AIDS.

According to National Academy of Medical Science (NAMS), Bir Hospital said that about 2% of the population in Nepal is affected by hepatitis i.e. about 6 lakhs of populations are infected by hepatitis. More of the patient dies due to liver cirrhosis or cancer.

The World Health Organization (WHO) said that about 60,000 of the people are in chronic hepatitis condition in the world.

Kala-azar or Leishmaniasis

It is a protozoan disease caused by flagellate Leishmania which is found in reticulo-endothelial system (liver, spleen, bone marrow) of human. It is also called as dum dum fever or black fever.

It is very common disease of Nepal (Tarai region), India (Bihar), Bangladesh, Burma and reported from Srilanka, Africa, China, South America and Mediterranean area.

Causative organism: The protozoan Leishmania donovani is the causative organism. It is digenetic parasite and completes its life cycle in two hosts; man and sand fly.

AIDS

AIDS (Acquired Immuno Deficiency Syndrome) also called slim disease is one of the most serious communicable diseases of present time. It is a viral disease that hampers the immune system of human body. Thus, the patients suffering from AIDS become unable to defend themselves against infections.

Cancer

Cancer is one of the most serious non-communicable diseases. It is abnormal and unorganized growth or multiplication of one or more body cells. It may occur in any tissue or part of the body. The uncontrolled growth of cells is called as neoplasm and the condition neoplasia. It usually occurs after the age of 35-40 years, but it may sometimes occur earlier too. The abnormal mass of cells that results from uncontrolled cell division is called a tumor.

Socially Significant Diseases

Man is a social animal and lives in highly complex societies. Societies are specially meant to make life easier, smoother and more comfortable. A society also offers competition, stress and strain. Such social factors, if prolonged, may cause mental tension and mental illness (like depression, anxiety, etc.) in some persons, which may create various behavioral changes in them. These changes may be disturbing for himself and his society too. Thus, any abnormal change that causes distress and discomfort to the lives of both the concerned person & the people around him may be termed as socially significant disease.

Human diseases: Tuberculosis

It is highly communicable bacterial disease often found among people living in dark and dirty congested places. The germs of TB may invade any part of body and multiply and destroy the tissues. However lungs are the favourite site of infection. On the basis of the site of infection TB may be, Pulmonary TB or extra pulmonary TB. In pulmonary TB site of infection is lungs while in extra pulmonary TB the site of infection is other parts of body except lungs.

Human diseases: Typhoid

It is a serious communicable disease caused by bacteria and is commonly called as enteric fever. The bacterium lives in the intestine and produces several intestinal disorders.

Occurrence: It is found throughout the world. It is most common in areas with lack of sanitation and poor standards of drinking water.

Human Blood group

Grouping of blood on the basis of nature of proteins present on the surface of RBC is called as blood group. The protein on the surface of RBC is called as antigen. With respect to the antigen present on the surface of RBC compatible protein is found in plasma. The protein in plasma is called as antibody. The antigens are denoted by capital alphabets while antibodies are denoted by small alphabets. There are many systems of blood grouping as more than 40 different types of antigens are found on the surface of RBC. However, ABO – system and Rh- system of grouping are of great importance for blood transfusion.

The ABO- system of blood grouping was first introduced by Karl Landsteiner in 1900 AD and

Human Ear

    The human ear is an organ of hearing and balance. It is called as statoacoustic organ. It has three parts; external ear, middle ear and inner ear.

External ear: - The external ear consists of two parts; pinna and auditory canal.

The pinna or helix or auricle is present on the side of head and is broad cartilaginous structure. Its posterior end without cartilage is called as lobule. Its hollow centre is called as concha. Its movement is regulated by auricular muscles which is vestigial in human.It collects, receives sound wave and sends the sound waves into the auditory canal.

Human Eye

Human eyes are special sense organs for the sense of vision and are called as photoreceptor organs. They are spherical structures present in the bony socket of the skull. The bony socket of skull is called as orbital cavity and it remaining filled with fatty tissues the movement of eye ball in the orbital cavity is regulated by rectus muscles and oblique muscles. The rectus muscles are anterior rectus, posterior rectus, superior rectus and inferior rectus while the oblique muscles are superior oblique and inferior oblique. Each eye is of about 2.5 cm diameter.

The eye ball remains protected by upper and lower eye lids. The eyebrows and eyelashes also protect the eyeball.

The eye ball gets secretions of meibomian gland, harderian gland, glands of Zeis and lacrimal gland. The secretion of meibomian and harderian glands is oily and lubricates the eyelids and cornea while the lacrimal gland secretes watery fluid, the tears. It makes eye ball moist, soft, clean and free from bacteria. The glands of Zeis are present at the base of eye lashes and their secretion keep eye lashes soft and smooth.

Internal Structure

                The internal structure of eye can be studied with the help of its vertical section. It consists of three concentric layers of tissues which are outer layer, middle layer and inner layer.