Golden rice is a genetically modified crop plant where the incorporated gene i's meant for

  • Vitamin B

  • Vitamin C

  • Omega 3

  • Omega 3


D.

Omega 3

Golden rice is a variety of rice produced through genetic engineering to biosynthesize  -carotene, a precursor of vitamin-A, in the edible parts of rice. 

710 Views

Which part of the tobacco plant is infected by Meloidogyne incognitia?

  • Leaf

  • Stem

  • Root

  • Root


C.

Root

The nematode inects the roots of the tobacco plant and result in root know disease.

925 Views

Which of the following is not required for any of the techniques of DNA fingerprinting available at present?

  • Zinc finger analysis

  • Restriction enzymes

  • DNA-DNA hybridization

  • DNA-DNA hybridization


A.

Zinc finger analysis

Zinc finger is a small structural motif that is characterised by the co-ordination of one or more Zn ions in order t stabilise the folds. 

2181 Views

With advancements in genetics, molecular biology and tissue culture, new traits have been incorporated into crop plants. Explain the main steps in breeding a new genetic variety of a crop. 


Plant breeding and improvement of crops is well supported by the governments and private companies. The major steps involved in the process are –
1. Collection of variability
2. Evaluation and selection of parents
3. Cross hybridisation among the selected parents
4. Selection and testing of superior recombinants
5. Testing, release and commercialisation of new cultivars

1. Collection of variability -Genetic variability is the primary requirement of breeding program, the wild character of plants is collected, preserved and characteristics for exploring natural genes called as germplasm collection.

2. Evaluation and selection of parents -The collected germplasm is then screened for the desirable character, followed by their multiplication and preparing for hybridization to obtain pure line.

3. Cross hybridisation among the selected parents
- Different characters are combined with two different parents e.g high quality protein gene is combined with disease resistant gene and developed a new cross hybrid.
4. Selection and testing of superior recombinants -The best combination is selected among the progeny; selection should be done very crucially with help of scientific community. The plant obtained in this step is superior to both parental plants. The plants are self-pollinated to obtain uniform generation, where character remains intact in the progeny.
5. Testing, release and commercialisation of new cultivars - Newly selected plant are evaluated (disease resistance, quality) by growing in research field and recognize management, irrigation requirement, followed by cultivation of the crop for 3 seasons under different climate. Then the plant is evaluated with present crop and defined useful or not.

666 Views

Advertisement

A pleiotropic gene

  • is expressed only in primitive plants.

  • is a gene evolved during Pliocene

  • controls a trait only in combination with another gene

  • controls a trait only in combination with another gene


D.

controls a trait only in combination with another gene

Pleiotropic gene is a gene that controls multiple traits is an individual. It is also called polyphenic gene, e.g., phenylketonuria causing multiple adverse effects due to the mutation in a single gene coding for enzyme phenylalanine hydroxylase.

767 Views

Advertisement
Advertisement