Respiration and Circulation — BIOLOGY STD 12 Science — Question

Within what age group sexually transmitted diseases (STDs) are reported to be very high. Mention three practices to avoid them.

Explain the significance of satellite DNA in DNA fingerprinting technique.

Teacher explains about the process of biofortification, in which he explains that, this method is useful in providing nutrition to large population. Akshay asked some question about this from his teacher.

1. What is biofortification?
2. What types of nutritional enrichment can be possible through this?
3. What is Atlas 66?
4. What values are shown by Akshay as biology student?

1. Name the tropical sugar cane variety grown in South India. How has it helped in improving the sugar cane quality grown in North India?
2. Identify ‘a’, ‘b’ and ‘c’ in the following table:

No.	Crop	Variety	Insect Pests
1.	Brassica	Pusa Gaurav	(a)
2.	Flat bean	Pusa Sem 2, Pusa Sem 3	(b)
3.	(c)	Pusa Sawani, Pusa A-4	Shoot and fruit borer

Parthenocarpy and apomixis have been observed in some plants. Give an example of each. State a similarity and a difference observed between the two processes.

Gene A, B, C and D are linked. By carrying breeding experiment and recording offspring phenotype the following cross over frequencies are determined.

What is the order of the genes on the linkage map?

Give reasons : Glottis is guarded by a flap called epiglottis.

Alveoli are very flexible.

Match the column A with B and rewrite correct pairs

	A	B
I	Mycoherbicides	Cactoblastis
II	Bacterial herbicides	Alternaria
III	Insects as herbicides	Xanthomonas

1. A DNA segment has a total of 1,500 nucleotides, out of which 410 are Guanine containing nucleotides. How many pyrimidine bases this segment possesses?
2. Draw a diagrammatic sketch of a portion of DNA segment to support your answer.