Question
Which one of the following lenses should be used to
correct the defect of astigmatism?Solution
Astigmatism is an optical defect in which visionis blurred due tothe inabilityof the optics of the eye to focus a point object into asharpfocusedimageontheretina.Thismaybe due to an irregular or toric curvature of the corneaorlens.Thetwotypesofastigmatismare regular and irregular. Irregular astigmatism is oftencausedbyacornealscarorscatteringinthe crystalline lens, and cannot be corrected by standard spectacle lenses, but can be corrected by contact lenses.
What is the term for the negative effect that a host plant has on the growth of an insect-pest that feeds on it?
Most abundant part of a plant cell wall is
Seed priming improves the
Which of the following is used to determine mechanical damage in legume seeds?
Centre of origin of Gossypium herbaceum is:
Which of the following field crops is most susceptible to lodging due to its tall stature and heavy panicle weight under high fertility and irrigation?
A type of grafting in which shallow, downward and inward cut ensuring V-shape incision in lower portion of rootstock and matching cut on the scion is ma...
Control of storage insects in nuts and dried fruits and vegetables can be achieved byÂ
What regulates the flow of food from the foregut to the midgut in insects?
National Milk Day is being celebrated onÂ