Health and Disease
Poor health can be caused by diseases. Often, different diseases interact, and this can lead to further health complications that don't seem related at first.
Poor health can be caused by diseases. Often, different diseases interact, and this can lead to further health complications that don't seem related at first.
Animals and plants both have transport systems for moving substances around. Water is transported from the roots to the leaves during transpiration in xylem vessels for photosynthesis. All cells inside phloem vessels use glucose made during photosynthesis for respiration.
The cells of plants are arranged in a similar fashion to those of other multicellular organisms. The cells of an organism form tissues, the tissues form organs, and the organs form organ systems.
Throughout our bodies, blood travels through blood vessels. There are three different types of blood vessels you should know about: Arteries, Capillaries and Veins.
Transporting materials between cells is necessary for multicellular organisms. Like many animals, the heart plays a key role in the human circulatory system, which transports blood around the body.
Your cells require oxygen for respiration, so you need to get it from the air into your bloodstream. You must also expel carbon dioxide from your bloodstream. All of this occurs in your lungs. Your lungs are forced to take in and expel air when you breathe.
There are trillions of cells in multicellular organisms like humans. Those cells have to work together to keep the organism going, which requires organisation.
You need to know about a few examples of exchange surfaces. Mammals exchange gases in their lungs and absorb nutrients in their small intestines. In plants, gas exchange occurs in the leaves. In fish, gas exchange occurs in the gills.
Substances dissolved in water are called soluble. In order to survive, living organisms must be able to exchange dissolved substances with their environment. Surface area and size affect the pace at which this can occur.