The harmful allele of sickle cell anemia | Class 12 Biology Chapter Human Health and Disease, Human Health and Disease NCERT Solutions

Is there any relationship between dedifferentiation and the higher degree of success achieved in plant tissue culture experiments?

Explain with the help of one example how genetically modified plants can:
(a) Reduce usage of chemical pesticides
(b) Enhance nutritional value of food crops

Give any two reasons why the patent on Basmati should not have gone to an American Company.

Many secondary metabolites of plants have medicinal properties. It is their misuse that creates problems. Justify the statement with an example.

How do we compute the age of a living tree?

You have studied the story of Pepper moths in England. Had the industries been removed, what impact could it have on the moth population? Discuss.

Why are proteins synthesised from Spirulina called single cell proteins?

In a pond, we see plants which are free-floating; rooted–submerged;
rooted emergent; rooted with floating leaves. Write the type of plants
against each of them.
Plant Name Type
a. Hydrilla _____________
b. Typha _____________
c. Nymphaea _____________
d. Lemna _____________
e. Vallisnaria _____________