The correct answer is A: cell
Energy. A solute can only move against concentration gradients using active transport which requires energy
Answer:
The bacterial flora in the intestines are essential to homeostasis in the body, they not only break down food so the nutrients can be absorbed, they produce vitamins like biotin and vitamin K and guard against harmful bacteria that enter the system. While your heart is a vital organ, the brain (and the nervous system that attaches to the brain) make up the most critical organ system in the human body. The digestive system ordinarily gets 20% to 25% of the oxygenated blood pumped out by the heart and the receptors in muscles provide the brain with information about body position and movement, the brain controls the contraction of skeletal muscle the nervous system regulates the speed at which food moves through the digestive tract.
Answer:
The leukocyte, commonly known as a white blood cell (or WBC), is a major component of the body’s defenses against disease. Leukocytes protect the body against invading microorganisms and body cells with mutated DNA, and they clean up debris. Platelets are essential for the repair of blood vessels when damage to them has occurred; they also provide growth factors for healing and repair.Although leukocytes and erythrocytes both originate from hematopoietic stem cells in the bone marrow, they are very different from each other in many significant ways. For instance, leukocytes are far less numerous than erythrocytes: Typically there are only 5000 to 10,000 per µL. They are also larger than erythrocytes and are the only formed elements that are complete cells, possessing a nucleus and organelles. And although there is just one type of erythrocyte, there are many types of leukocytes. Most of these types have a much shorter lifespan than that of erythrocytes, some as short as a few hours or even a few minutes in the case of acute infection.
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Explanation:
DNA (or deoxyribonucleic acid) is the molecule that carries the genetic information in all cellular forms of life and some viruses. It belongs to a class of molecules called the nucleic acids, which are polynucleotides - that is, long chains of nucleotides.
