CBSE PORTAL : (Download) CBSE Class-12 Sample Paper And Marking Scheme 2017-18 : Biotechnology |  |
| (Download) CBSE Class-12 Sample Paper And Marking Scheme 2017-18 : Biotechnology Posted: 21 Jan 2018 10:07 PM PST |
| BAC | YAC |
| Effective in Bacteria | Effective in Yeast |
| It has genes for maintenance and replication of F-factor | It has telomere, centromere and ARS from yeast chromosome |
| Can accommodate up to 300kb of DNA | can be used for cloning DNA upto 1 MB in size. |
(Any two)
SECTION B
7. Tissue engineering :Naturally derived or synthetic materials may be engineered into "scaffolds" that when implanted in the body could provide a template that allows the body’s own cells to grow and form new tissues Such implants could function without triggering immune responses. Genetically-modified animals may also provide a source of cells, tissues, and organs for xenografts. 1
8. Metagenomics approach has been developed to identify and select microbial genes synthesizing novel molecules. This approach directly utilizes the large number of microbial genomes present in an environmental niche, for example in soil, in water such as ocean or in human gut. These genomes are contributed by both the culturable and the non-culturable variety of microbes and together constitute what has been termed as metagenome
The collective DNA is extracted from a sample of soil, water or any other environmental niche. It is subjected to restriction digestion using restriction endonucleases and the fragments are cloned into suitable vectors. The clones are then screened for presence of a variety of molecules.
9. Plant regeneration pathways The plants can be regenerated by either organogenesis and somatic embryogenesis. Organogenesis means formation of organs like shoots from the cultured explants .Miller and Skoog experimentally proved that formation of shoot or root first on the cultured tissue depends on the relative concentration of auxin and cytokinin. If auxins are high in the medium, then it promotes rooting while if cytokinins are high, shoot formation is promoted.
In somatic embryogenesis, the totipotent cells may undergo embryogenic pathway to form somatic embryos ,which can be grown to regenerate into complete plants. Generally, somatic embryos resemble the zygotic embryos (seed embryos) except in their place of origin and larger size. For the first time, Steward in 1958 and Reinert in 1959 independently reported the somatic embryogenesis from carrot cultures.
10
1. Transformation : In this technique. we put the recombinant DNA in the medium having host cells .Host cells will uptake the desired DNA provided the host cells are competent .If they are not competent , we make them competent by treating it with the cold calcium chloride.
Mandel and Higa proposed the technique in 1970.
2.Trasfection : The desired DNA is mixed with the cationic liposome’s or dextran and layered on the host cells and is then taken inside by the host cells.
3.Electroporation : We pass electricity of desired voltage through the culture of the cells resulting in transient ( temporary ) pores in the cell membrane and through these pores DNA enters.
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(Download) CBSE Class-10 Sample Paper And Marking Scheme 2017-18 : English Communicative
Posted: 21 Jan 2018 10:06 PM PST
(Download) CBSE Class-10 Sample Paper And Marking Scheme 2017-18 :
English Communicative
SECTION –A: READING (20 Marks)
Q1. Read the passage given below and answer the questions that follow:
1. Cricket is a global passion, played everywhere from Test match arenas to village greens, tropical beaches and dusty back lots. Cricket is the world's second most popular spectator sport after football.
2. The origin of cricket is somewhere in the Dark Ages. All research concedes that the game derived from a very old, widespread and uncomplicated pastime by which one player served up an object, be it a small piece
of wood or a ball, and another hit it with a suitably fashioned club. Cricket was first recorded in 16th-century England, and it was played in grammar schools, farm communities and everywhere in between. But things really took off when 18th-century nobles realised it was a great sport.
3. The oldest surviving set of cricket laws date from 1744 – printed on a handkerchief, naturally. It's now in the MCC Museum at Lord’s in London. The oldest permanent fixture is the annual Eton v Harrow match,played since 1805. A young Lord Byron turned out for Harrow in the first match, though history doesn't record how poetic – or “mad, bad and dangerous” – his bowling was.
4. The first international match was in 1877 when Australia beat England in Melbourne. The match was dubbed a “Test”, since the gruelling nature of playing over five days was deemed the ultimate “test” for any
side. But it was Australia’s first win on English soil – in 1882 at The Oval in London – that led to matches between the two nations being christened the Ashes. Following the defeat, newspapers published an obituary
mourning “the death of English cricket”, adding that “the body will be cremated and the ashes taken to Australia”.
5. A One Day International (ODI) is a form of limited overs cricket, played between two teams with international status, in which each team faces a fixed number of overs, usually 50. The Cricket World Cup is played in this format. The international one-day game is a late twentieth-century development. The first ODI was played on 5 January 1971 between Australia and England at the Melbourne Cricket Ground. (344words)
1.1 Attempt any eight of the following questions on the basis of the passage you have read.(1X8=8Marks)
i. According to the passage, how did the game of Cricket originate?
ii. Where can we find the oldest sets of Cricket laws?
iii. Which match did Lord Byron play?
iv. When was the first international match played?
v. Which countries played that match?
vi. Why were the matches between Australia and England titled “The Ashes”?
vii. In which format is the Cricket world cup played ?
viii. When did the ODIs begin?
ix. Which word in paragraph no.5 means the same as ‘exhausting’?
Q2.Read the passage given below and answer the questions that follow:
1. Politeness has been well defined as benevolence in trifles. It is the desire to put those whom we meet perfectly at their ease, and save them from every kind of petty discomfort and annoyance. The limited part of benevolence called politeness requires only an inclination to make them happy temporarily,while they are in our presence, and when this can be done without any sacrifice on our part or only with a slight sacrifice of personal comfort.
2. Politeness is said to be one of the important characteristics of civilised person. Politeness is the art of choosing among your thoughts. It must be implemented in every walk of life. When we deal with people elder to us we are polite. But, an honest polite person is polite with everyone, people of lower status, workers and even children. Not only with humans but also with animals we must be polite as they are our helpers.
3. Politeness is a skill. Like any other skill, you can master it with practice. The greatest enemy of politeness is ego. To be a polite person, you have to sacrifice your ego. It is difficult for an egoist to be polite. You have to imply politeness in your thinking, speech and actions. Actions work more than words. Polite actions will give fine results. Politeness will reduce your stress and boost you to be productive.Apart from your present benefits, you protect your future. Being polite makes you mentally healthy. In our daily life we come across many incidents with people nearby and ourselves.
4. Different rules of behaviour have to be observed, accordingly as we are in the street or in the drawingroom,at home or at school, in the company of friends or of strangers. There is also to be considered the great diversity of social etiquette which distinguishes one country from another.
5. Politeness, besides being a duty that we owe to others, is a valuable possession for ourselves. It costs nothing, and yet may in many cases bring much profit. The great advantage of this excellence of conduct
was very clearly expressed by Dr. Johnson, when he said that the difference between a well-bred and an ill- bred man is that one immediately attracts your liking, the other your dislike. (378 words)
2.1 On the basis of your reading of the passage, answer any four of the following questions in about 30-40 words each : (2X4=8)
i. Why is politeness called as limited part of benevolence?
ii. List some of the persons we should be polite to?
iii. Why is it difficult for an egoist to be polite?
iv. What are the benefits of being polite?
v. Which rules of behaviour are to be observed?
2.2 On the basis of your reading of the passage, fill in any two of the following blanks with appropriate words/phrases. (1X2=2)
i. Politeness is an art of choosing_________.
ii. An honest polite person is polite with ___________.
iii. To others, we _____________________.
2.3. Attempt any two of the following. Find out the words that mean the same as under: (1x2 =2)
i. ‘insignificant’ (Paragraph 1)
ii. ‘manners’ (Paragraph 4)
iii. ‘civil’(Paragraph 5)
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