Which microscope is used to see internal structures of cells in a natural state? darkfield microscope phase-contrast microscope two-photon microscopy confocal microscopy

Phase contrast microscope

Explanation:

It is used for viewing biological structures not visible under the microscope. It is used for viewing microrganisms live

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.