Answer:
a. 0.5 grams b. 0.25
Explanation:
Just use the half-life formula(I linked it below)
a. 4(1/2)^90/30=1/2
b. 4(1/2)^120/30=1/4
The answer is protect the body from infection by pathogens
The physical barrier is made of epithelial cells, mostly will be keratinized to increase their sturdiness further. They will impede the pathogen physically by barricading the cells, makes the pathogen could not invade deeper part of the body. Histamine and antibodies should be the role of immune cells, not epithelial.
<span>Red blood cells normally have a biconcave shape (picture a donut, but instead of a hole through the centre there's just a downward slope to the centre of the cell). If the cell takes on water, it will increase in size and the sloped areas will start to flatten out. If the cell loses water, it will begin to shrivel. Use these observations and your understanding of osmosis to answer the question!</span>
How to cut what open? and a mask.
Answer:
LiquidsEdit
Because the particles can move, liquids don't have a definite shape, and they can flow. Because the particles are still packed close together, liquids can't easily be compressed and keep the same volume.
Explanation: