Question
Explain with the help of one example how genetically modified plants can:
  1. Reduce usage of chemical pesticides.
  2. Enhance nutritional value of food crops.

Answer

  1. Reduce usage of chemical pesticides: Bt toxin is produced by a bacterium called Bacillus thuringiensis (Bt for short). Bt toxin gene has been cloned from the bacteria and been expressed in plants to provide resistance to insects without the need for insecticides; in effect created a bio-pesticide. Examples are Bt cotton, Bt com, rice, tomato, potato and soyabean etc.
  2. Enhance nutritional value of food crops: Golden rice is the transgenic variety of basmati rice which gives high yield and rich in vitamin A, so it is used in the deficiency of vitamin-A causing night blindness and skin disorder.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions


Shown above is the electron micrograph (EM) picture of 'beads-on-string'.
  1. Identify and explain the detailed structure of a bead with the help of a labelled diagram.
  2. Describe the packaging of 'beads-on-string'in a eukaryotic cell.
Give an account of energy flow in an ecosystem.
  1. Compare, giving reasons, the J-shaped and S-shaped models of population growth of a species.
  2. Explain "fitness of a species" as mentioned by Darwin.
Haemophilia is a sex–linked recessive disease. Study the pedigree analysis given below showing the inheritance of the disease in a family and answer the questions that follow.

  1. Give the evidence from the above analysis which suggests that the disease is:
    1. Sex–linked and,
    2. Caused by a recessive allele.
  2. Write the possible genotypes of the individuals ‘2’ and ‘5’.
What are the methods of cancer detection? Describe the common approaches for treatment of cancer.
Which property of DNA double helix led Watson and Crick to hypothesise semi-conservative mode of DNA replication? Explain.
  1. Draw a simplified model of phosphorus cycling in a terrestrial ecosystem.
  2. Write the importance of such cycles in ecosystems.
Explain a monohybrid cross taking seed coat colour as a trait in Pisum sativum. Work out the cross up to F2 generation.
We are told that evolution is a continuing phenomenon for all living things. Are humans also evolving? Justify your answer.
The following is the illustration of the sequence of ovarian events (a – i) in a human female.

Identify the figure that illustrates ovulation and mention the stage of oogenesis it represents.