Answer:
<u>Light microscope</u>:
- use a beam of light to produce magnified images
- can be used to examine living cells and tissues
<u>Scanning electron microscope</u>:
- use a beam of electrons to produce magnified images
- can be used to examine DNA
- can be used to examine cells
<u>Transmission electron microscope</u>:
- use a beam of electrons to produce magnified images
- can be used to examine DNA
- can be used to examine cells
Explanation:
Light microscope: is a commonly used microscope also known as compound microscope. Magnifies images from 40X upto 1000X. It uses ray of visible light to produce a magnified image. The light microscope can be used to view specimen of both living and dead cells or tissues. However, it doesn't give a detailed view of a specimen like electron microscope.
Scanning electron microscope: It uses electron beam as an illuminating source. It has a much higher resolving power than light microscope because it uses electrons instead of light. It magnifies object upto 500000 times the actual size. Internal structures can also be viewed. However, only dead specimen can be used because the beam of electrons can kill the cells. They are of two types:
- <u>Scanning electron microscope(SEM): </u>an electron beam passes over the specimen's surface and displaces electrons which are then focused on a screen to form an image. Images appear in 3-D
- <u>Transmission electron microscope: </u>electromagnets magnify the image by passing beam of electrons through a thin specimen. Images appear in 2-D
<span> Amoebic dysentery is caused by the amoeba Entamoeba histolytica. This protozoan exists in nature in the cyst form and is transmitted by contaminated food and water. In patients, the amoebas revert to trophozoites and invade the intestinal lining.
Your answer is C.
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Answer:
first 4, then 2, then 1, and lastly 3
Explanation:
First, RNA polymerase binds to the promoter region of a gene on the DNA and initiates transcription. Transcription is the process by which we get mRNA (coding RNA) which is used as a template for protein synthesis. Then, in transcription, the resulting mRNA undergoes modification and maturation. This involves removal of introns, addition of 3'-poly-A tail and 5'-cap. Introns are sequences that do not code for protein and are hence removed. The structure that removes introns is the spliceosome. Thirdly, mature mRNA travels to the cytoplasm. Ribosome (composed of rRNA) binds to mRNA and tRNA to start the process of protein synthesis. The process of formation of protein is called translation. Lastly, the primary structure of protein may undergo folding to form a tertiary structure.
Think of DNA as a code and think of your brain as a computer. Computers must have code to tell them what to do! Without DNA, we wouldn’t be able to function! People who are missing some “code” aka a strand of DNA may have some disabilities such as blindness. This is because their brain doesn’t known what to do with their eyes because they don’t have “code” to tell them what to do!
Hope that this helped.
<h3><u>Answer;</u> </h3>
= 3.68 g/cm³
<h3><u>Explanation;</u></h3>
Density is given by dividing the mass of a substance by its volume.
Thus; Density = mass/ volume
In this case; mass = 92 g and Volume = 25 cm³
Therefore;
Density = 92 g/ 25 cm³
<u>= 3.68 g/cm³</u>
