In the poem, ‘A Thing of Beauty’, Keats shows his unhappiness with his fellow human beings through some negative aspects of life such as hopelessness, sadness and lack of noble ways, which are part of life. If we follow unhealthy and wicked paths in life, this will harm us. These paths or circumstances summarily make human beings unhappy.

RNA interference (RNAi) is a mechanism for sequence-specific gene silencing triggered by double-stranded (ds) RNA. RNAi constitutes an effective antiviral defense mechanism in many organisms. Accordingly, viruses interact with the RNAi pathway at different levels. In the process of silencing of mRNA, a eukaryotic cell produces a strand of RNA which is complimentary to the mRNA of the parasite, thus making it's RNA double stranded. This inhibits the parasite to translate it's RNA to any kind of protein and thus it prevents infection.

A n s w e r :

dsRNA gain entry into eukaryotic cell either through:
(i) infection by virus having RNA genome or
(ii) mobile genetic elements (transposons) that replicate via an RNA intermediate.

Cry and cry are different. Cry refers to the protein whereas cry is the gene of bacterium Bacillus thuringiensis. As this gene encodes for the crystal protein and hence named cry after crystal. 

def calcresult(): 
    i = 9 
    while i > 1: 
    if (i % 2 == 0): 
        x = i % 2 
        i = i - 1 
    else: 
        i = i - 2 
        x = i 
    print x * *2 

Ans:

Output:

To achieve sustainable development, the following needs to be done:

(i) Limiting the human population.
(ii) Technological progress should be input efficient and not input consuming.
(iii) Renewable resources should be extracted on a sustainable basis, that is, the rate of
extraction should not exceed rate of regeneration.
(iv) For non-renewable resources, rate of depletion should not exceed the rate of creation of renewable substitutes.
(v) Inefficiencies arising from pollution should be corrected.

Following are some of the most common solutions to the environmental issue:

1. Replace disposal items with reusable items.
2. The use of paper should be avoided.
3. Conserve water and electricity.
4. Support environmental friendly practices.
5. Recycle the waste to conserve natural resources.

Sustainable development is that process of development which meets the needs of present generation without reducing the ability of future generation to meet their own needs.

Strategies for Sustainable Development.

(i) Use of non-conventional sources of energy.
(ii) Use of cleaner fuels: LPG, Gobargas in rural areas and CNG in Urban areas.
(iii) Use of Solar energy and wind power.
(iv) Shift to organic farming.
(v) Recycle the wastes
(vi) Public means of transport.
(vii) Traditional knowledge and practices.
(viii) Establishment of Mini-Hydel plants.
(ix) Biopest Control

Some of the factors responsible for land degradation is

(i) loss of vegetation occurring due to deforestation.
(ii) Forest fires and over grazing.
(iii) Improper crop rotation.
(iv) Encroachment into forest lands.
(v) Shifting cultivation.
(vi) Indiscriminate use of agrochemical such as fertilizers and pesticides.
(vii) Improper planning and management of irrigation systems.
(viii) Extraction of ground water in excess of the recharge capacity.
(ix) Poverty of the agriculture-dependent people.
(x) Non-adoption of adequate soil conservation measures.

Land degradation means decrese in the quality of the land .such that its nutrients and fertility is lost and is in incapable of growing crops.

The causes of Land degradation are:-

1) Soil pollution.

2) Soil Erosion.

3) Over grazing.

4) Extraction of minerals.

5) drought, cyclone can also weaken the soil

The environment is able to perform these functions without any interruption as long as demand on these functions are within its carrying capacity.

Carrying capacity implies two things:

(i) Resource extraction should remain below the rate of resource regeneration.
(ii) Generation of wastes should remain within the absorption capacity of the environment.

If these two conditions are not fulfilled, then environmental crisis occurs.

Global warming is a gradual increase in the average temperature of the earth’s lower atmosphere.
Global warming is caused by man-made increase in carbon dioxide (Co₂) and other greenhouse gases through the burning of fossil fuels and deforestation.

Some of the long term results of global warming are as follow:
(i) Melting of polar ice with a resulting rise in sea level and coastal flooding.
(ii) Extinction of species as ecological niches disappear.
(iii) more frequent tropical storms and
(iv) An increased incidence of tropical diseases.

Air pollution is responsible for major harmful effects on human health, animal lives, natural ecosystems and the man-made environment. It is also responsible for climate change due to the enhanced greenhouse effect, acid rain, and the depletion of the ozone layer that constitute important global environmental problems. Air pollution can damage crops and trees in a variety of ways. Ground-level ozone can lead to reductions in agricultural crop and commercial forest yields, reduced growth and survivability of tree seedlings, and increased plant susceptibility to disease, pests and other environmental stresses (such as harsh weather).

Land degradation refers to a decline in the overall quality of soil, water or vegetation condition, commonly caused by human activities.

Some of the factors responsible for land degradation is

(i) loss of vegetation occurring due to deforestation.
(ii) Forest fires and over grazing.
(iii) Improper crop rotation.
(iv) Encroachment into forest lands.
(v) Shifting cultivation.
(vi) Indiscriminate use of agrochemical such as fertilizers and pesticides.
(vii) Improper planning and management of irrigation systems.
(viii) Extraction of ground water in excess of the recharge capacity.
(ix) Poverty of the agriculture-dependent people.
(x) Non-adoption of adequate soil conservation measures.

Application of Biotechnology in Agriculture involves scientific techniques such as Genetically Modified Organisms, Bt Cotton, Pest Resistant Plants. It helps in modifying plants, animals, and microorganisms and improve their agricultural productivity. Techniques like vaccines, tissue culture, genetic engineering are also used.

NIEO :- New International Economic Order is a economic system introduced to replace Bretton Wood System in 1970s by some developing countries through United Nations Conference on trade and development to promote their interests by improving their terms of trade.

Three major systems of land revenue collection existed in India. They were – Zaminidari, Ryotwari and Mahalwari.

1. Zamindari System was introduced by Cornwallis in 1793 through Permanent Settlement Act.
2. Ryotwari System was introduced by Thomas Munro in 1820.
3. Mahalwari system was introduced in 1833 during the period of William Bentick.