Human Health and Disease — BIOLOGY STD 12 Science — Question

What do you understand by the term biopesticide? Name and explain the mode of action of a popular biopesticide. Biopesticides are methods of controlling pests that rely on natural predation rather than introduced chemicals/ or living organisms used to kill pests.

Differentiate between perisperm and endosperm by giving one example of each.

Flowering plants have developed many devices to discourage self-pollination and to encourage cross pollination. Explain three such devices.

In a Mendelian monohybrid cross, the F₂ generation shows identical genotypic and phenotypic ratios. What does it tell us about the nature of alleles involved? Justify your answer.

Write a short note on Apomixis and polyembryony.

What is antibiotics? Antibiotic production is the most significant discoveries of the 20th century. Explain with examples.###Explain Antibiotics###Discovery of antibiotics is a chance Discovery - Explain.

What are viruses parasitising bacteria called? Draw a well labelled diagram of the same.

List six advantages of "ex-situ" approach to conservation of biodiversity.

Rearrange the following in the correct sequence to accomplish an important biotechnological reaction:

1. In vitro synthesis of copies of DNA of interest.
2. Chemically synthesised oligonucleotides.
3. Enzyme DNA-polymerase.
4. Complementary region of DNA.
5. Genomic DNA template.
6. Nucleotides provided.
7. Primers.
8. Thermostable DNA-polymerase (from Thermus aquatics).
9. Denaturation of ds-DNA.

Can you think and answer how a reporter enzyme can be used to monitor transformation of host cells by foreign DNA in addition to a selectable marker?