most of a cell's life is spent in a non-dividing state the interphase
<span>Humans—and other large multicellular animals—are made up of four basic tissue types: epithelial tissue, connective tissue, muscle tissue, and nervous tissue.
</span>Epithelial tissue<span> consists of tightly packed sheets of cells that cover surfaces—including the outside of the body—and line body cavities. For instance, the outer layer of your skin is an epithelial tissue, and so is the lining of your small intestine.</span>
Epithelial cells are polarized, meaning that they have a top and a bottom side. The apical<span>, top, side of an epithelial cell faces the inside of a cavity or the outside of a structure and is usually exposed to fluid or air. The </span>basal<span>, bottom, side faces the underlying cells. For instance, the apical sides of intestinal cells have finger-like structures that increase surface area for absorbing nutrients.
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Connective tissue consists of cells suspended in an extracellular matrix. In most cases, the matrix is made up of protein fibers like collagen and fibrin in a solid, liquid, or jellylike ground substance. Connective tissue supports and, as the name suggests, connects other tissues.
Muscle tissue<span> is essential for keeping the body upright, allowing it to move, and even pumping blood and pushing food through the digestive tract.</span>
Nervous tissue<span> is involved in sensing stimuli—external or internal cues—and processing and transmitting information. It consists of two main types of cells: neurons, or nerve cells, and glia.
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All of these tissues are essential in keeping the body running, including the cardiovascular system in which the heart is involved. All of these tissues play a key role in maintaining the function of the heart, whether it be indirectly, or directly, each of these will keep your heart sustained, but without them you wont live long lol.
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They were written by hand on animal skin
Answer:
Parathyroid hormone is released when dietary calcium levels are low.
Explanation:
Parathyroid hormone is considered to be a vital hormone involved in regulating the calcium levels of the body. The hormone is secreted by parathyroid glands which are located behind thyroid glands in neck region. This hormone regulates the calcium level of the body by putting its action through bones, intestine and kidneys.
In actual there is a negative feedback system in the body through which parathyroid levels are controlled. When calcium levels in the blood get very low, the gland is stimulated to secrete more parathyroid hormone while when calcium is very high in the blood, it prevent the release of parathyroid hormone.
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Answer:
Punctuated equilibrium refers to<u> B. Species that evolved very rapidly during relatively brief time spans</u>
Explanation:
The theory of evolution states that organisms heritable characteristics change over time to form new lineages or species. Punctuated equilibrium is an evolutionary theory that explains the sudden appearance of novel species on the fossil record. In this theory, the species likely evolved quickly to survive in a significantly altered environment.