ZOO101 Current Paper by Ch Ismail

ZOO101 Current Solved

Efforts by CH Ismail

Q1. Ethidium Bromide?

gels is retarded by a factor of - 15%.

2)Parts of microscope

(i)Eyepiece:

An eyepiece is that part of an optical system, which is directed to the viewer. It is a construction of at least one or more lenses. The function of the eyepiece in a microscope is to convert the realenlarged-intermediate-image from the objective into an enlargedvirtual-image. It contains the ocular lens, which the user looks through to see the magnified specimen. The ocular lens has a magnification that can range from 5x to 30x, but 10x or 15x is the most common setting.

(ii)

Objective lenses:

•  It combines with the eyepiece lens to increase magnification levels. Microscopes generally feature three or four objective lenses, with magnification levels ranging 4x to 100x.
• Objective revolvers are used in microscopes with multiple objective lenses that have different magnification factors.
• An objective (lens) is that part of an optical system, which is directed to the object. It´s task is to collect the light rays that are reflected from the observed item. The objective generates a real-optical image.

Q1. Limitations….?

• Very low contrast of most biological samples.
• The practical limit to magnification with a light microscope is around 1300X. Although higher magnifications are possible, it becomes increasingly difficult to maintain image

Clearity as the magnification increases

• Low apparent OPTICAL RESOLUTION due to the material used.
• Samples that are naturally colorless and transparent cannot be seen well, e.g. many types of mammalian cells. These samples often have to be stained before viewing. Samples that do have their own color can be seen without

Preparation

Q2. Homogeneous mixtures and heterogeneous?

mixtures. A homogeneous mixture is a mixture that is uniform throughout. A heterogeneous mixture is a mixture that is not uniform throughout, i.e., ingredients of the mixture are distributed unequally. Air is a homogeneous mixture of different gases, including oxygen, nitrogen, carbon dioxide, and water vapour.

3)Saw microtome and Laser microtome? long

• It is especially used for hard materials such as teeth or bones.
• The microtome of this type has a recessed rotating saw, which slices through the sample.
• The minimal cut thickness is approximately 30 μm and can be made for comparatively large samples.

Laser microtome

• It cuts tissue or other material with the help of photons instead of steel blades.
• The method is contact-free and enables to cut tissue in its native state.
• Special preparation techniques are not required.
• Cutting by optical breakdown.
• The thickness achievable is between 10 and 100 μm.

4)Multilayer filtration differ b/w hot and cold filtration? Long

• This can refer to multiple layers of different material, including sand, gravel, or