Assertion : Dragonflies can be used to decrease occurrence of diseases like malaria, dengue, etc.
Reason : Baculoviruses are effective in controlling may insects and other arthropods.

Assertion : Dragonflies can be used to decrease occurrence of diseases like malaria, dengue, etc. Reason : Baculoviruses are effective in controlling many insects and other arthropods.

Direction. In the follwing questions, a statement of assertion is followed by a statement of reason. While answering a question, you are required to choose the correct are out of the given four responses and mark it as (A). If both assertion and reason are true and reason is the correct explanation of the assertion, (B) if both assertion and reason are true but reason is not correct explanation of the assertion. (C) if assertion is true, but reason if false, (D) if both assertion and reason are false Assertion : A transformer can be used to increase/ decrease both voltage and the current. Reason : In a transformer, e_p I_p = e_sI_s and accordingly, if we gain in voltage, we lose in current and vice-versa.

Read the following five statements (A to E) and select the option with all correct statements: The greater the BOD of waste water, more is its polluting potential. (B). Statins produced by the yeast Trichoderma polysporum act as blood -cholesterol lowering agents. (C) Baculoviruses are pathohens that attack insects and other arthropods. (D) The majority of baculoviruses used as biological control agents are in the genus Nucleopolyhedrovirus. (E) Treatment of waste water is done by the autotrophic microbes naturally present in the sewage.

Assertion : NAND is a universal gate. Reason : It can be used to describe all other logic gates.

Assertion : Magnification power of microscopes can be decreeased by increasing the focal length of the lens used. Reason : Due to constructional limitations , the focal length of lens cannot be decreased beyond certain unit.

Ecological Indicators The presence of dragonflies can reveal changes in the water ecosystems more quickly than studying other animals or plants. In fact, from the nymph to the adult stage, the dragonfly has a significant, positive ecological impact. Dragonfly eggs are laid and hatched in or near water, so their lives impact both water and land ecosystems. Once hatched, dragonfly nymphs can breathe underwater which enables them to eat mosquito larvae, other aquatic insects and worms, and even small aquatic vertebrates like tadpoles and small fish and in the air. Adult dragonflies capture and eat adult mosquitoes. Community wide mosquito control programs that spray insecticides to kill adult mosquitoes also kill dragonflies. Assertion: Releasing dragonflies in areas where there is an outbreak of malarial diseases can be an environment friendly method of control. Reason: Dragon flies are dominant species and will not allow mosquitoes to reproduce

Assertion: A cadmium is used for making control rods in nuclear reactors. Reason: Cadmium is very effective in slowing down the speed of neutrons.

Assertion : Colon bacilli can be used to produce glycoproteins that can be used fot hepatitis B treatment Reason : Hepatitis B is a viral disease and its spread in the body can be checked using interferons.