The ozone layer absorbs UV rays.
This is true.
An easy way to remember this is that Cis-acting elements are physically linked to a set of structural genes. So promoters and operators are physically linked to the gene they express. They are cis acting because they are on the same strand as the structural gene they control.
On the other side, trans means that they can come from somewhere else and act. A good example of this would be regulatory proteins. These could be expressed somewhere else (or on a different strand) and then bind and affect transcription.
Meiosis.
Meisois is is the reproduction of the sex cells (sperm and egg), while mitosis is between a regular cell. Another difference is that Meiosis splits into 4 cells, while mitosis splits into 2.
Hope this helps!
I think the correct answer is the third option. Tonsils are large lymphoid nodules that are located in the walls of the pharynx. Tonsils are a part of the lymphatic system and is one of the fighters against infections and the first line of defense for inhaled or ingested pathogens. On their surfaces, they have specialized antigen cells which are called as M cells that would allow the uptake of antigens that is produced by pathogens. The most common condition that could happen to the tonsils would be tonsillitis. Symptoms of these are sore throat, fever and swollen tonsils. It can be caused by different viruses and bacteria.
Answer:
blastocyst / blastula forms
