Class 12 Biology - Chapter Human Health and Disease NCERT Solutions | Explain what is meant by metastasis.
Explain what is meant by metastasis.
The property of metastasis is exhibited by malignant tumors. It is the pathological process of spreading cancerous cells to the different parts of the body. These cells divide uncontrollably, forming a mass of cells called tumor. From the tumor, some cells get sloughed off and enter into the blood stream. From the blood stream, these cells reach distant parts of the body and therefore, initiate the formation of new tumors by dividing actively.
More Questions From Class 12 Biology - Chapter Human Health and Diseas
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(a) Amoebiasis
(b) Malaria
(c) Ascariasis
(d) Pneumonia - Q:- Draw a well-labelled diagram of an antibody molecule.
- Q:- What are the various public health measures, which you would suggest as safeguard against infectious diseases?
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- Q:- List the harmful effects caused by alcohol/drug abuse.
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- Q:- Name the primary and secondary lymphoid organs.
- Q:- Differentiate the following and give examples of each:
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(b) Active and passive immunity - Q:- How is a cancerous cell different from a normal cell?
- Q:- Discuss with your teacher what does a suitable gene means, in the context of DNA vaccines.
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- Q:-
Fill in the blanks:
(a) Humans reproduce __________. (asexually/sexually)
(b) Humans are__________. (oviparous/viviparous/ovoviviparous)
(c) Fertilization is __________ in humans. (external/internal)
(d) Male and female gametes are __________. (diploid/haploid)
(e) Zygote is __________. (diploid/haploid)
(f) The process of release of the ovum from a mature follicle is called__________.
(g) Ovulation is induced by a hormone called the __________.
(h) The fusion of male and female gametes is called _____________.
(i) Fertilisation takes place in _____________.
(j) Zygote divides to form _____________which is implanted in uterus.
(k) The structure which provides vascular connection between fetus and uterus is called ____________. - Q:- What do you think is the significance of reproductive health in a society?
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