A compound microscope forms an inverted image of an object. In which of the following cases it is likely to create difficulties? a. Looking at small germs. b.Looking at circular spots. c. Looking at a vertical tube containing some water.

(i) Keep a glass slab on a blank paper and draw its outline PQRS as shown in the figure. (ii) Draw an inclined straight line on the side of PQ so that it intersect PQ at N. Pierce two pins vertically at two points A and B along the line. (iii) Look at the pins A and B from the opposite side of the slab and pierce pins C and D vertically so that the images of A and B are in line with C and D. (iv) Now remove the chip and the pins and draw a straight line going through points C and D so that it intersects SR at M. (v) Join points M and N. Observe the incident ray AN and emergent ray MD. Questions: (a) What is your observation about the emergent ray and incident ray ?

A scientist was studying the production of a protein that was released by an animal cell into a culture medium, she found that the protein only appeared in the culture medium after the added a few drops of a hormone to the cell. Before adding the hormone, she labelled the protein inside the cell with a fluorescent dye and looked at the cell under the lgiht microscope. The dye was seen in flattened sheets and tube. like structures throughout the cell, and in stacks of flattened sac-like structures. after adding the hormone, the dye was aslo seen as small dots clustered against the cell membrane, Which statement most likely explains these observations?

Read the following statements regarding the various techniques used in cancer detection. (i) Cancer detection is based on biopsy and histopathological studies of the tissue, and blood and bone marrow tests for increased cell counts in case of leukaemia. (ii) In biopsy, a piece of the suspected tissue cut into thin sections is stained and examined under microscope by a pathologist. (iii) Techniques like radiography (use of X-rays), CT (computed tomography) and MRI(magnetic resonance imaging) are very useful to detect cancers of the internal organs. (iv) Computed tomography uses strong magnetic fileds and non-ionising radiations to detect physiological changes in living tissues. (v) MRI uses X-rays and ionising radiation to generate a 3-D image of the internal structure of an object. Which of the above statements are incorrect ?