Answer:
Stem cells are cells in the human body that have the ability to develop into many other body cell types. Stem cells are very useful for drug development, research, they aren't likely to be rejected in transplants, and are used to repair damaged or diseased cells and tissues. However, they cannot be grown for long periods of time, there are very small numbers in each tissue and cell making them very hard to find, and for certain studies they have been shown to cause cancer. To be honest, using them in research does have its pros and cons, they are very useful and easier to use in research, plus they can help repair damaged and diseased cell tissues. But at the same time they can be difficult to use correctly and properly, it can cause serious health problems if cancer doesn't take place. I think that using them in research is okay, as long as they are used correctly and properly.
Hope this helps! :)
A Eukaryotic cell contains a nucleus; more than one chromosome and is typically a multi-celled organism. Both plant and animal cells are eukaryotic cells. A Prokaryotic cell does not contain a nucleus. It only contains one
chromosome and is a single-celled organism. It was the only form of life
on earth for millions of years. Examples of a Prokaryotic cell are the
different types of bacteria present today.
I remember the secondary structure by visualizing it. Understand that primary structure is just the order of the amino acids. The tertiary structure is the 3dimensional configuration of the whole protein molecule with multiple interactions guiding its fold (disulfide bonds, ionic interactions, hydrogen bonds, van der walls). Secondary structure is a step towards the conformation of the protein where it is made up of either alpha-helices or beta-pleated sheets. The alpha helices look like a spiraling staircase while the beta-pleated sheets look like a repetition of long loops. These two structures hold itself by hydrogen bonds.
