31 Years NEET Previous Year Questions: Strategies for Enhancement in Food Production - 1 (Old NCERT) - NEET MCQ

It is possible to induce mutations artificially through use of chemicals or radiations (like gamma radiations), and selecting and using the plants that have the desirable character as a source in breeding – this process is called mutation breeding.

Cross-breeding is the process where the breeding between the two individuals of different species takes place.“Hisardale" is a new breed of sheep developed by crossing Bikaneri ewes and Marino rams in Punjab.

Inbreeding strategies allow the desirable qualities of more closely related individuals to be continued within the same breed for 4-6 generations. It increases homozygosity and thus, is necessary for evolving a pureline. Inbreeding exposes harmful recessive genes that are eliminated by selection. It also helps in accumulation of superior genes and elimination of less desirable genes. Therefore, this approach where there is selection at each step, increases the productivity of inbred population. However, continued inbreeding, especially close inbreeding usually leads to reduce fertility and even productivity. This is called inbreeding depression.

When breeding is between animals of the same breed for 4-6 generation, it is called inbreeding. Inbreeding, as a rule, increases homozygosity. Thus, inbreeding is necessary if we want to obtain a pureline in any animal.

Ley farming is an agricultural system where the field is alternately seeded for grain and left fallow for growing hay or used for pasture. During the fallow/pasture period the soil is filled with roots of grasses and other plants. New ploughing mixes them in the soil and also increases the amount of nitrogen in the soil especially when legume forage are used. It also protects soil from erosion by maintaining constant soil coverage.

According to Darwin resistance to pesticides has a genetic basis due to presence of certain alleles. In the presence of pesticides, the insects devoid of the allele for resistance die while the ones having them survive. They are selected by nature.

The phenomenon of having one or more genomes in addition to the normal for the species is called polyploidy.

The long -term prospects for a truly human civilization depend in a large measure on control of human diseases.

The major difficulty in the biological control of insects’ pests is that the predator develops a preference to other diets and may itself become a pest. Biological control is mainly referred to the introduction of living organisms which destroy other harmful organisms.

The method of producing thousands of plants through tissue culture is called micro-propagation. Each of these plants will be genetically identical to the original plant from which they were grown, i.e., they are somaclones. Many important food plants like tomato, banana, apple have been produed on commercial scale using this method.

During the period 1960 to 2000 rice production went up from 35 million tonnes to 89.5 million tonnes. This was due to the development of semi-dwarf varieties of rice. There are 2,00,000 varieties of rice in India.

Germplasm collection is the first step of  plant breeding programmes. As genetic variability is the root of any breeding programme. In many crops pre-existing genetic variability is available from wild relatives of the crop. Collection and preservation of all the different wild varieties, species and relatives of the cultivated species (followed by their characteristics) is a pre requisite for effective exploitation of natural genes available in the population.

Spirulina is SCP rich in protein, vitamins & minerals. 250 gram biomass of Methylophilus methylotrophus produces 25tonn protein/day while cow of 250 Kg. produces only 200 gm. protein/day.
Common button mushrooms are a very rich source of vitamin D. A rice variety has been developed which is very rich in iron content.

Green revolution is the introduction of high-yielding varieties of seeds and the increased use of fertilizers and irrigation, which provided the increase in production needed to make India selfsufficient in food grains, thus improving agriculture in India. Green revolution in India occurred in 1960.s

Vector DNA are the DNA molecules that can carry a foreign DNA segment and replicate inside the host cells. Vector DNA may be plasmids, a bacteriophage, cosmids, yeast artificial chromosomes.

Meristem is most suitable for raising virus free plants for micropropagation.

RNA interference has been used to develop plants resistant to nematodes. RNA interference is a double stranded RNA (dsRNA) induced for gene silencing phenomenon.

‘Himgiri’ developed by hybridisation and selection for disease resistance against rust pathogens is a variety of wheat. It is resistant to leaf/stripe rust and hill bunt.

Jaya and Ratna are two rice varieties developed for green revolution in India.
• The scientific name of Jaya is IET-723. This paddy variety takes about 130 days to grow and the grain is long, bold and white. Its yield is 50-60 quintals per hectare.
• The scientific name of ‘Ratna’ is IET1411. It takes about 130-135 days to grow. The grain is long, slender and white. Its yield is 45-50 quintal/hectare.

An improved variety of transgenic basmati rice gives high yield and is rich in vitamin A.

Breeding of crops with high levels of minerals, vitamin and minerals is called biofortification. This is most practical aspect to improve the health of people.

Genetic variation present among plant cells during tissue culture is called somaclonal variation. The term somaclonal variation is also used for the genetic variation present in plants regenerated from a single culture. This variation has been used to develop several useful varieties against resistance to diseases and pests, better yield, better quality etc. 

Xanthomonas campestris is not used as a biopesticide. Xanthomonas campestris is a plant pathogen that causes black rot in cotton plants.

An RNA molecule whose base sequence is complementary to that of the RNA transcript of a gene, ie. the sense RNA, such  as a messenger RNA (m RNA). Hence, an  antisense RNA can undergo base pairing  with its complementary mRNA sequence. This blocks gene expression, either by preventing access for ribosome  to translate the mRNA or by triggering degradation of the double stranded RNA by ribonuclease enzymes. Antisense RNA and DNA both have therapeutic potential for modifying the activity of disease causing genes.  

Paexcilomyces Lilacinus is proved effective for biological control of nematodal  disease in plants. it is easily produced in vitro, Rhizosphere competent, attack the eggs of several nematodes species and treatment of plant matter, eg, seed tuber, can be effective.

Use of only disease free seeds and use of disease resistant varieties are the most important control measures that could be taken to successfully grow chickpea in an area where bacterial blight disease is common. 

Newcastle disease (ND) is a hig hly contagious, generalised viral disease of domestic poultry and wild birds characterised by gastro-intestinal, respiratory and nervous signs.

The bullock is castrated and therefore secretion of testosterone is not adequate.

Exotic Species - a species that has been introduced from another geographic region to an area outside its natural range. Examples are water hyacinth, Lantana camara.

Hybrid vigour is also called Helorosis which is measured in terms of size growth rate / field and number of other characters. Hybridisation increases vigour and fertility. It is exploited by crosing of two in bred parental lines. It is best maintained in vegetatively reproducing crops because of genetic recombinations.