Answer:
Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period. Index fossils are useful because they tell the relative ages of the rock layers in which they occur.
Answer:
Capillaries pass oxygen and waste between blood and cells.
Explanation:
Answer:
Bifocal lenses are used for people who are both nearsighted and farsighted. It is common for people who are over the age of 40 to begin to notice a change in their vision and require the need for bifocals. As we age, our eyes begin to have trouble focusing on objects at different distances away.
Explanation:
Red blood cells will swell and burst. The
reason behind this is that red blood cells are okay when they are in
the plasma (the watery part of the blood) because the solutes in plasma
are so well balanced that plasma is rendered isotonic. An isotonic
solution is a type of solution that has the same salt concentration as
its surrounding environment and thus the substances around it e.g. cells
neither gain nor lose water. In the blood plasma, the red blood cells
neither lose nor gain water and so they remain intact.<span>However distilled
water is hypotonic (has less or no solutes) and therefore osmosis will
take place when red blood cell which have a higher solute concentration
are placed in it. Water molecules will leave the distilled water and
pass into the red blood cells through the semi-permeable membrane of the
cells in an attempt to equalize the difference in osmotic pressure on
either side of the membrane. In so doing, water will accumulate in the
cell which will then swell to capacity and ultimately burst.</span>
<span>c. cilia and flagella
</span>Which two cellular structures help cells move around?
NOT:
a. nuclei and cell walls
b. chloroplasts and endomembrane systems
<span>d. ribosomes and mitochondria</span>
