Bihar Board - Class 12 Biology - Chapter 8: Human Health and Disease Long Answer Question

Q.1. What causes adolescents to start using drugs? How can the use of drugs be avoided?

A.1. Few reasons that cause adolescents to start consuming drugs are:

• Curiosity to experiment

• For excitement and adventure sake

• Peer pressure

• In an attempt to push one’s physical and mental boundaries and produce more work

• To overcome depression and frustration caused due to failure in miscellaneous activities.

• Lack of support from family

Remedial measures to avoid usage of drugs are:

• Avoid pressuring children to perform beyond his/her academic capabilities

• Educate and counsel children to deal with stress and disturbances in life

• Seek help from family, peers

• Stay alert on the danger signs by adopting suitable measures to treat them

• Seek medical/professional help for rehabilitation and de-addiction.

Q.2. How to detect cancer? What are a few approaches to treat cancer?

A.2. Cancer can be detected at early stages and early detection is essential. Following are a few can diagnosis and detection areas:

• Tests for increases cell counts(blood cancer)

• Histo-pathological and biopsy of blood/tissues/bone marrow

• Radiography, CT, MRI to detect cancer of internal organs

• Identification of cancer-specific antigens

• Application of molecular biology techniques to detect genes with inherited susceptibility to a few cancers

Treatment of cancer: Listed below are a few approaches that can be used to treat cancer.

• Surgery to remove the tumor

• Immunotherapy to boost the killing of cancer cells

• Radiotherapy to kill cancerous cells

• Chemotherapy

• Administration of biological response mediators such as ∝-interferons that activate the immune system thus helping in destroying the tumor

Q.3. What is a recombinant DNA vaccine? List two such vaccines. State their advantages.

A.3. Recombinant DNA vaccines consist of plasmid, which is a small circular DNA. It contains a pathogen DNA to produce one or two specific proteins of the pathogen. This DNA is then inserted into the yeast or bacteria cells to utilize the machinery of the cell to generate pathogen’s polypeptides. These vaccines can be used to stimulate the organization of immune responses. Vaccines hence produced are used on a large scale for the manufacture of

• Hepatitis-B vaccine (yeast)

• Bird flu DNA vaccine

Some of their advantages are:

• These vaccines are always more beneficial than attenuated vaccines as they do not mutate again

• They are distinctly pure and specific and evokes strong immune responses.

Q.4. What is Ringworm? What are the different types of ringworm?

A.4.Ringworm is a type of skin infection, caused by the fungus. It is a contagious skin disorder, which can spread by skin contact with an infected person. There are different types of ringworm and are mainly classified based on the body parts which get infected. The most common forms of ringworm are tinea pedis, tinea capitis, tinea cruris and tinea corporis.  

Types of Ringworm are:

Ringworm is classified based on the part of the body it affects.

1. Tinea corporis: This fungal infection might occur in any part of the body. 

2. Tinea capitis:  It is also called scalp ringworm. This fungal infection affects the scalp.

3. Tinea cruris: This fungal infection affects the skin around the buttocks, inner thighs, and groin. It is also known as the Jock itch.

4. Tinea pedis: This fungal infection affects both the foot, in between the fingernails and toenails. It is also known as Athlete’s foot. 

Q.5.What Is Typhoid? List out the symptoms of Typhoid?

A.5.Typhoid is aninfectious disease caused by the Salmonella typhi or S. Typhi bacteria, which infects the intestinal tract and the blood cells of an individual.

Listed below are a few common symptoms of Typhoid:

• Headache

• Dry cough

• Sweating

• Skin Rashes

• Muscle aches

• Abdominal pain

• Weakness and fatigue

• Diarrhea or constipation

• Loss of appetite and weight loss

• Sustained fever or fever with the elevating body temperature.

Q.6.Name the cells HIV attacks first, when it gains entry into a human body. How does this virus replicate further to cause immunodeficiency in the body?

Answer: The HIV virus attacks the macrophages first in the human body. The further replication of virus causes immuno deficiency in the following way

• RNA is replicated to form viral DNA by the enzyme reverse transcriptase.

• Viral DNA gets incorporated into the host cell’s DNA and directs the infected cells to produce viruses.

• Macrophages continue to produce virus particles and function as HIV factories.

• The virus particles enter helper T-lymphocytes in the blood, where they continue to replicate and produce viral progenies.

• The number of helper T-lymphocytes progressively decreases in the body of the infected person.

• With the decrease in the number of T-cells, the immunity also decreases. The person is unable to produce any immune response even against common bacteria like Mycobacterium, parasites like Toxoplasma, viruses and fungi.

Q.7. Prevention is better than cure’ is an apt slogan to safeguard adolescents from drug abuse. List any 6 steps that could be taken in this regard.
Answer:
Six steps that could be taken to prevent adolescents from drug alcohol abuse are as follows

• A child should not be pushed unduly to perform beyond his/her limits in studies, sports or any other activities.

• Educating and counseling him/her to face problems and stresses and accept disappointments and failures as part of life.

• Parents and teachers can identify the danger signs and take appropriate steps to diagnose the malady and underlying causes.

• Help should be taken from qualified psychologists and psychiatrists.

• Parents and teachers should become more supportive.

• Help of close friends and relatives can also be taken.