You may have seen the strange, fuzzy anomaly growing wildly on the foods you've forgotten in the back of your refrigerator. These molds are microscopic, multicellular fungi that are rather resilient. Not only can these micro-organisms withstand...
Communicable diseases, also called infectious diseases, are diseases that can spread from person to person. According to the National Institutes of Health (NIH), they are caused by germs, which are small living things found everywhere in the soil,...
Cells are the biological units of life, and all living organisms are composed of one or more cells. Some organisms, like bacteria, are made up of a single cell responsible for all the functions performed by the organism. More complicated living...
Lipids are a broad group of diverse and naturally occurring, organic compounds. Lipids play a large role when it comes to energy storage and the structure of cells. They are divided into four main groups consisting of fats, lipids, hormones and...
The kidneys appear bean-shaped and are near the middle back, just below the rib cage. These sophisticated reprocessing organs go through approximately 200 quarts of blood each day to sift out 2 quarts of waste and excess water, according to the...
Increased respiratory rate is one of the most obvious adaptations you make to meet the demands of exercise. The rate of blood flow and gas exchange throughout the pulmonary system will increase during exercise to supply sufficient amounts of...
Paramecium are a genus of organisms within the kingdom Protista, which represents single cell organisms and some multicellular algae. While the organisms in the more familiar plant and animal kingdoms are composed of many cells that work together...
Bacteria cells function quite differently from human cells, from the function of the cell as a whole, right down to the individual structures in each cell. Bacteria exist in nature as individual cells. While some bacteria work together in a group,...
UV (ultraviolet) radiation refers to a portion of the electromagnetic spectrum consisting of short wavelengths that cannot be detected by the human eye. The main source of UV radiation affecting Earth comes from the sun. The three varieties of...
Parasites can infect the intestines for years. Two types of intestinal parasites exist: helminths and protozoa. Helminths are multicellular and include tapeworms, pinworms and roundworms. Mature helminths cannot reproduce in the body. Protozoa, on...
Viruses are a class of tiny and deadly infectious agents that are distinct from other types of germs such as bacteria. Because viruses are not composed of cells like other organisms, they are not even considered to be alive by many scientists....
Fermentation is a metabolic strategy for extracting energy from sugar molecules, including glucose. While it's a much less efficient energy-extraction strategy than respiration, which is used by larger, multicellular organisms, many smaller...
Sickle cell anemia is a heritable disorder that results from a mutation in the gene for hemoglobin, the protein that carries oxygen from the lungs to the tissues. The disease affects many different cell types, leading to symptoms including pain...
Intestinal human parasites can be grouped into two categories---protozoa and helminths. Protozoa are single-celled organisms capable of reproducing inside the body, resulting in potentially serious infections. Protozoan parasites are typically...
You may have heard that fermented foods are better for you than nonfermented foods, or you may simply wonder what fermentation is and what it does to the food you're eating. Lactose is a commonly fermented sugar, and when a lactose-containing food...
Monera is one of five kingdoms of life, the others of which are Protista, Fungi, Plantae, and Anamalia. The Monera kingdom includes both cyanobacteria, or blue-green algae, and true bacteria, also called eubacteria. The discovery of...
Iodine is a trace mineral critical for the function of your thyroid gland. Seawater is rich in iodine, and thus foods from the sea are potent dietary sources. The highest measured iodine intake has been found in northern Japan, where seaweed makes...
Lactic acid fermentation is a metabolic strategy that humans, other animals, and various bacterial species use to generate energy from glucose molecules under certain conditions. Specifically, when oxygen is scarce, cells can burn glucose...
In colloquial terms, respiration refers to the process of breathing. In scientific and medical terminology, however, respiration is a series of chemical reactions taking place at the cellular level. In fact, respiration is defined as the reactions...
Fungus belongs to the kingdom Fungi, bacteria to Monera and protists to Protista. Although these organisms are often thought to be detrimental to human health, many of them actually exist in the foods you enjoy, as well as on the body itself. The...
The liver is a large organ located at the upper right portion of the abdomen. It has many functions, such as filtering and detoxifying the blood and making bile to aid in digestion. Imaging scans such as CT or MRI sometimes find a liver mass or...
Influenza and pneumonia describe disease conditions of the respiratory system. Symptoms may include, but are not limited to, fevers, chills, cough, sputum production, malaise, runny nose, muscle aches and chest pain. Severe disease requires...
The blood is a complex chemical soup made up of water-based plasma, several types of cells and a wide variety of molecules. It serves many purposes in the body, from transporting oxygen and nutrients to cells to allowing cell-to-cell communication...
Humans have circulatory systems designed much like water delivery systems. A pump—the heart—circulates fluid through a series of pipes, or blood vessels. The purpose of this system is to maintain the cells. In a multicellular organism,...
Nematodes are highly abundant, non-segmented worms that are present in a variety of habitats. Many are free-living (such as those that live in the soil), while others are parasitic and must attach themselves to a plant, insect, animal or human...
Bacteria that grow on a surface have different behaviors than free-floating bacteria. A community of bacteria and other single-celled organisms living and growing on a surface is called a biofilm. Many of the bacteria living in your body grow as...
The intestines are part of the human digestive system that connect the stomach to the anus. The main function of the intestines is the absorption of food products. This makes them susceptible to attack by parasites, organisms that grow and feed...
Humans and other living organisms rely on glucose and other sources of nutrition to provide for cellular energy needs. Depending on the organism, some cells depend on oxygen to run reactions that extract energy from glucose, while other cells do...
Algae supplements are often marketed for their abilities to boost your immune system and promote healthy joints. It's also been claimed that algae can be used to treat viruses and cancer, but there is little scientific evidence to support such...
