Stem cells grown on a hard, rigid surface are biased into differentiating into a bone cell lineage. <span />
The answer is A; all of the above
The answer is "D"
The body's first line of defense is also known as Innate immunity and incudes mucous membranes. Both the intact skin and mucous membranes of the body offer a high degree of protection against pathogens.
A good example is the mucous membrane of the respiratory tract. It is lined up with cilia and covered with mucus. The coordinated beating of the cilia drives the mucus up to the nose and mouth where the trapped bacteria can be expelled.
(Lymph nodes and white blood cells belong to the second line of defense, not the first)
Answer:
Hi there!
Your answer is:
It is very important for the cell membrane to be <em>semi-permeable</em> because the ability to pick and choose what comes in and out of the cell keeps the cell safe! The membrane can choose to block out nasty germs and can also choose to get rid of internal waste.
An example of when this is important is in this scenario:
Let's say the cells are in a really salty solution. Naturally, salt will want to pull the water out of the cell. If the membrane <u>wasn't</u><u> </u> semi permeable, the water would listen to the salt and leave the cell. This would cause cell death. <u>BECAU</u><u>SE</u> the membrane is semi permeable, they can choose <em>not</em> to give the salt any water, keeping them alive
Hope this helps
Answer:
Evolution
Explanation:
Evolution is a gradual change in a population that occurs overtime in a species.