State whether it would be better to use the 4x or 40x object

State whether it would be better to use the 4x or 40x objective and why? Measuring dimensions of chloroplasts in Elodea cells. 4x or 40x? _______ why? _______. Measuring the total distance a paramecium will swim in search of food in a Petri dish. Paramecia can grow to approx. 330 mu m in length. 4x or 40x? _______ why? _______

Solution

A 10x eye piece with 40X objective gives a magnification factor of 400. The magnification factor 400 means, it is possible to see an object 400 times larger than original. A magnification of 10x eye piece with 4X objective gives only 40 magnification factor. If lower the magnification then the working distance is longer and if higher the magnification, then the working distance is shorter. Thus it is better to use 40X instead of 4x as 40x has higher magnification. Within Elodea cells, chloroplast show cytoplasmic streaming. As Elodea is a water plant shows a bigger vacuole and surrounding chloroplasts near the cell membrane. Elodea shows two layers of cells, one of the layers could be seen through high power 40x objective. 400 magnifications (10 x 40x) shows limited depth. To see both layers with chloroplasts, fine adjustment knob is enough along with 40x objective.