Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Biology

Explain the various types of cancer

What is a cistron?

Cancer is one of the most dreaded diseases. Explain 'Contact inhibition' and 'Metastasis' with respect to the disease

Name any two techniques that are useful in detecting cancers of internal organs.

Why are cancer patients often given α-interferon as part of the treatment?

State the difference between the structural genes in a Transcription Unit of Prokaryotes and Eukaryotes.

Give one example of point mutation.

Explain (in one or two lines) the function of the following:

tRNA

Explain (in one or two lines) the function of the following:

Exons

How is a cancerous cell different from a normal cell?

Explain what is meant by metastasis.

Answer the following question.
You are conducting artificial hybridization on papaya and potato. Which one of them would require the step of emasculation and why? However, for both, you will use the process of bagging. Justify giving one reason.

Answer the following question.
Two children, A and B aged 4 and 5 years respectively visited a hospital with a similar genetic disorder. The girl A was provided enzyme-replacement therapy and was advised to revisit periodically for further treatment. The girl, B was, however, given a therapy that did not require revisit for further treatment.

Name the ailments the two girls were suffering from?

Emasculation and bagging are the two important steps carried during artificial hybridization to obtain superior varieties of desired plants. Explain giving reasons, in which types of flowers and at what stages are the two processes carried out.

Answer the following question.
Two children, A and B aged 4 and 5 years respectively visited a hospital with a similar genetic disorder. The girl A was provided enzyme-replacement therapy and was advised to revisit periodically for further treatment. The girl, B was, however, given a therapy that did not require revisit for further treatment.

Why did the treatment provided to girl A required repeated visits?

Answer the following question.
Two children, A and B aged 4 and 5 years respectively visited a hospital with a similar genetic disorder. The girl A was provided enzyme-replacement therapy and was advised to revisit periodically for further treatment. The girl, B was, however, given a therapy that did not require revisit for further treatment.

How was the girl B cured permanently?

Differentiate between a benign tumor and a malignant tumor.

While planning for an artificial hybridization programme involving dioecious plants, which of the following steps would not be relevant?

Haploid plants are preferred over diploids for mutation study because in haploids ______.

Albinism is known to be due to an autosomal recessive mutation. The first child of a couple with normal skin pigmentation was an albino. What is the probability that their second child will also be an albino?