A) Crossing over is the mechanism of genetic variation that results from the exchange of gene segments between non-sister chomatids.
The laboratory is full of chemicals and other hazardous substances. So, it is very important to keep all the safety precautions before entering in the laboratory to avoid any mis-happening.
Here are some precautions, which one should take before entering lab:
- Before entering the laboratory one must wear all the safety equipment including gloves, goggles, apron, and others.
- Make sure you are not wearing any inflammable thing and you are fully covered, as in some laboratory, harmful radiation are also present.
- Make sure your hair are tied in properly and the shoes are covered.
<span>Yes, all living organisms are made of at least one cell (cell theory). But, remember, viruses and prions, which cause diseases, are not technically living things, and they are NOT made of cells. Also, if asked a question similar to this on a biology test, the teacher may be trying for an answer similar to: "Organisms are made of different organ systems, which are made of various related organs, which are made of different tissues working together, which are made of cells". </span>
