12TH CBSE BIO Human Health and Disease QUS ANS

 How cancer can be treated.

Answer : Cancer treatment
The common approaches for treatment of cancer are:
(i) Surgery: cancrousThe tumour cells are removed with the help of surgery to check the spread cancerous cells.
(ii) Radiation therapy: A lethal irradiation of tumour cell is done,taking proper care of the normal
tissues surrounding the tumour mass.
(iii) Chemotherapy: Cancerous cells are killed by several chemotherapeutic drugs.These drugs
exhibit side effects like hair loss,anaemia.
(iv) Immunotherapy: In this method, biological modifiers like - interferons are used which activate
the immune system and help in destroying the tumour.

List at least five symptoms of mental illness
Answer : Symptoms of mental illness
(1) Depression
(2) Insomnia or excessive sleeping
(3) Compulsive action.
(4) Feeling of hopelessness.
(5) Serious thoughts of suicide
(6) Unreasonable phobias.

What are causes of mental illness?
Answer : These causes are:
(i) Changes in the brain
(ii) hereditary factors
(iii) Childhood experiences
(iv) home atmosphere and
(v) special factors.
Brain is the organ which controls behaviour,and thus change in its structure of functioning can
lead to mental illness.

What are causes of mental illness?
Answer : These causes are:
(i) Changes in the brain
(ii) hereditary factors
(iii) Childhood experiences
(iv) home atmosphere and
(v) special factors.
Brain is the organ which controls behaviour,and thus change in its structure of functioning can lead to mental illness.

Tobacco addiction is due to nicotine present in it.Mention any four effects of nicotine on human body.
Answer : Effects of nicotine
(i) It stimulates conduction of nerve impulses.
(ii)It relaxes the muscles.
(iii)It releases adrenaline.
(iv) It retards foetal growth in expecting mothers

Name of the plant from which following drugs are obtained:
(i) Opium and its derivatives
(ii) Chars
(ii) Marijuana
(iv) Caffeine
(v) Cocaine
(vi) LSD
Answer : (i)Fruits of Poppy plant (Papaver somniferum)
(ii) Cannabis sativa
(iii) Cannabis sativa
(iv) Coffea arabica
(v) Erythroxylon coca
(vi) Claviceps purpurea

Name the drug yielding part of plant from which following drugs are obtained:
(i) Bhang
(ii) Caffeine
(iii) LSD
(iv) Marijuana
(v) Opium and its derivatives
(vi) Cocaine.
Answer : (i) Leaves and flowering shoots
(ii) Dried leaves and seeds
(iii) Fruiting bodies
(iv) Dried flowering tops of plant
(v) Latex of unripe capsules (fruits)
(vi) Dried leaves and young twigs.

Name the following:
(a) The vector of dengue fever.
(b) A vaccine produced by recombinant DNA technology.
(c) The type of immunity that is present at the time of birth.
(d) A fish that helps in eradication of mosquito larvae.
Answer : (a) Aedes mosquito
(b) Hepatitis-B vaccine
(c) lnnate immunity
(d) Gambusia fish

Mention the important functions or roles played by our immune system.
Answer : (i) The immune system recognises foreign antigens and responds to them.
(ii) It keeps a memory of the antigen( s).
(iii) It plays an important role in autoimmune diseases.
(iv). It is responsible for the allergic reactions.
(v) It decides the suitability of organ transplantation

How is a cancerous cell different from a normal cell?
Cancer cells are different from normal cells as they
(i) continue dividing ceaselessly
(ii) divide in an uncontrolled manner.
(iii) do not undergo differentiation
(iv) form an everygrowing tumour by a accumulation.
(v) do not remain confined to the part of the body where they are formed
(vi) invade the neighbouring tissue and dislocate their functions
(vii) spead throughtout the body, forming secondary tumours

The following are some well known abbreviations, which have been used in this chapter. Expand each one to its full form.
(i) MALT
(ii) CMI
(iii) AIDS
(iv) NACO
(v) HIV
Answer : (i) MALT - Mucosal Associated Lymphoid Tissue
(ii) CMI - Cell-Mediated Immunity
(iii) AIDS - Acquired Immuno Deficiency Syndrome
(iv) NACO - National AIDS Control Organisation
(v) HIV - Human Immunodeficiency