"Cells are so little, so they can maximize their ratio of surface area to volume. Smaller cells have a higher ratio which allow more molecules and ions move across the cell membrane per unit of cytoplasmic volume. Cells are so small because they need to be able to get the nutrients in and the waste out quickly."
Divergent evolution is when two different species share the same ancestral origins but have evolved differently whereas convergent evolution is when species with different ancestral origins have developed similar features.
In convergent evolution, two species that are not necessarily closely related develop similar features often as a result of adaptation to similar conditions.
Answer:
Bone.
Explanation:
Calcium is one of the important element present in the body. Calcium plays an important role in the muscle contraction. The calcium ions also acts as a signalling molecule during cell signalling.
The calcium is present in our extracellular fluids, bones, and teeth. The major constituent of calcium is present in the bone. The bone consists of around 90% body;s calcium.
Thus, the correct answer is option (b).
Exposure to environmental tobacco smoke causes approximately 45 to 46,000 non smokers to die of heat diseases annually. Smoking harms the cardiovascular system in many ways which include; damaging the lining of arteries, reduces HDL, good choresterol, Raises LML, bad cholesterol, increases blood pressure and heart rate, it also causes the platelets to stick together in the blood stream and speeds the development of fatty deposits in the arteries among other risk factors.
Answer:
As the spies of a cactus are modified leaves, they have ar spaces.
Explanation:
However, leaves of cactus are not like every other leaf. These leaves are in the form of spines to save the amount of water that the cactus needs.
Most of the amount of water, cactus s saving in its root. Also, the stem of a cactus is used for making food, and this is also the way of saving the water.
