Answer:
e. All of the above are correct.
Explanation:
Active transport is a type of transport in living systems in which molecules/ions/substances are moved or transported against their concentration gradient i.e. from a region where the substance is LOW to a region which it is HIGH, across a membrane. Since molecules are transported across a memembrane against their concentration gradient, an energy input in form of ATP is needed to do so.
Active transport is used in living systems to transport out secretory products and waste material against concentration gradients, take up nutrients from the environment against concentrations gradients etc. Since ions are substance moved by active transport from a low region to high region, there is an imbalance in the intracellular concentration of ions, such as Na, K etc.
Since there is no equilibrium in the concentration of ions on opposite sides of the membrane, an electric potential is formed across the membrane i.e. one part of the membrane will be more positively charged than the other.
The answer for the above question is the Avascular Necrosis. It occurs as an interruption in the blood flow within the bone resulting in the death of the hematopoietic cells, osteocytes, and marrow fat cells making up the bony structure. It is also called osteonecrosis or ischemic bone necrosis, which occurs when there is loss of blood to the bone, since the bone is a living tissue that needs blood, this interruption of blood supply will result to the death of the bone.
Answer: Nuclear fusion
Reasoning: most of a stars life is in the main sequence phase. This is the phase where nuclear fusion turns hydrogen into helium.
Answer:
Fertilization, which is the union of sperm and egg, occurs deep within the flower after pollination. When a pollen grain lands on the stigma, it generates a tiny tube tipped with sperm. The tube fits into a conduit called a style in the female pistil.
Explanation:
<span>Jul 7, 2008 - Ok, this includes "hierarchy structural levels biology." Principles in Biology ... What is the highest level in life's structural hierarchy? - Yahoo .</span><span>The structure of living organisms including those of entire populations and ... is life?'. In the biological sciences, the following hierarchical levels are recognized: ...</span><span>
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