Life Cycle, Processes & Properties, SCH-SPO

None of us are born looking exactly the way that we do today; this is because humans, like other species, undergo a series of changes as they mature and age, in accordance with their biological life cycle. This process can look very different across different species. In many simple organisms and in higher animals, the life cycle is completed within a single generation, while in most plants, the life cycle is multigenerational.
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Life Cycle, Processes & Properties Encyclopedia Articles By Title

schistosomiasis
schistosomiasis, group of chronic disorders caused by small parasitic flatworms (family Schistosomatidae) commonly......
schizoaffective disorder
schizoaffective disorder, mental disorder characterized by a combination of mood (affective) symptoms, such as......
schizophrenia
schizophrenia, any of a group of severe mental disorders that have in common symptoms such as hallucinations, delusions,......
Schmidt sting pain index
Schmidt sting pain index, measure of the relative amount of pain that various insects of the order Hymenoptera......
Schneirla, Theodore Christian
Theodore Christian Schneirla was an American animal psychologist who performed some of the first studies on the......
schooling behaviour
schooling behaviour, Activity characteristic of clupeiform fish (herrings, anchovies, and allies) in which many......
sciatica
sciatica, pain along the sciatic nerve, which runs from the lower back down the legs. Sciatica often develops following......
scleritis
scleritis, inflammation of the sclera, the white part of the eye. The inflammation is immune-mediated and is commonly......
scleroderma
scleroderma, a chronic disease of the skin that also can affect the blood vessels and various internal organs.......
sclerotin
sclerotin, a dark-brown biological pigment formed by an enzyme-catalyzed tanning of protein. Sclerotin is found......
sclerotium
sclerotium, a persistent, vegetative, resting spore of certain fungi (e.g., Botrytis, Sclerotium). It consists......
scoliosis
scoliosis, lateral deviation of the spine. Scoliosis is a type of curvature of the...
scorch
scorch, symptom of plant disease in which tissue is “burned” because of unfavourable conditions or infection by......
scrapie
scrapie, fatal neurodegenerative disease of sheep and goats. Scrapie has been endemic in British sheep, particularly......
scrofula
scrofula, condition caused by the bacterium Mycobacterium tuberculosis, in which the organism infects the lymph......
scrub typhus
scrub typhus, acute infectious disease in humans that is caused by the parasite Orientia tsutsugamushi and is transmitted......
scurvy
scurvy, one of the oldest-known nutritional disorders of humankind, caused by a dietary lack of vitamin C (ascorbic......
seasonal affective disorder
seasonal affective disorder (SAD), mood disorder characterized by recurring depression in autumn and winter, separated......
seborrheic dermatitis
seborrheic dermatitis, a type of dermatitis...
secondary sex character
secondary sex character, physical feature related to the sex of an organism that emerges during puberty, or the......
seed dispersal
seed dispersal, in botany, the movement or spread of seeds away from the parent plant. Given that seeds are essentially......
segmentation
segmentation, in zoology, the condition of being constructed of a linear series of repeating parts, each being......
selective feeding
selective feeding, food procurement in which the animal exercises choice over the type of food being taken, as......
self-fertilization
self-fertilization, fusion of male and female gametes (sex cells) produced by the same individual. Self-fertilization......
semicircular canal
semicircular canal, any of three loop-shaped organs in the inner ear that help control balance and stability by......
senses
senses, means by which animals detect and respond to stimuli in their internal and external environments. The senses......
sensory neuron
sensory neuron, nerve cell that carries information about changes in external and internal environments to the......
separation anxiety disorder
separation anxiety disorder, condition characterized by intense and prolonged concern, dread, worry, or apprehension......
sepsis
sepsis, systemic inflammatory condition that occurs as a complication of infection and in severe cases may be associated......
septic arthritis
septic arthritis, acute inflammation of one or more joints caused by infection. In septic arthritis the joints......
septic shock
septic shock, severe and potentially life-threatening condition characterized particularly by dangerously low blood......
septicemia
septicemia, infection resulting from the presence of bacteria in the blood (bacteremia). The onset of septicemia......
serum sickness
serum sickness, an allergic reaction to medicines that contain animal proteins or to antiserum injected into an......
sex chromosome
sex chromosome, either of a pair of chromosomes that determine whether an individual is male or female. The sex......
sex hormone
sex hormone, a chemical substance produced by a sex gland or other organ that has an effect on the sexual features......
sexual differentiation
sexual differentiation, in human embryology, the process by which the male and female sexual organs develop from......
sexual dimorphism
sexual dimorphism, the differences in appearance between males and females of the same species, such as in colour,......
sexual dysfunction
sexual dysfunction, the inability of a person to experience sexual arousal or to achieve sexual satisfaction under......
sexual intercourse
sexual intercourse, reproductive act in which the male reproductive organ (in humans and other higher animals)......
sexual reproduction
sexual reproduction, the production of new organisms by the combination of genetic information of two individuals......
sexual response cycle
sexual response cycle, pattern of physiologic events occurring during sexual arousal and intercourse. In both men......
sexually transmitted disease
sexually transmitted disease (STD), any disease (such as syphilis, gonorrhea, AIDS, or a genital form of herpes......
Sheehan’s syndrome
Sheehan’s syndrome, insufficiency of pituitary hormones (hypopituitarism), caused by destruction of cells of the......
shellfish poisoning
shellfish poisoning, illness in humans resulting from the eating of certain mussels and clams. The source of the......
shigellosis
shigellosis, infection of the gastrointestinal tract by bacteria of the genus Shigella. The illness produces cramplike......
shock
shock, in physiology, failure of the circulatory system to supply sufficient blood to peripheral tissues to meet......
sick building syndrome
sick building syndrome (SBS), term applied to a situation in which some or all the people occupying a building......
sickle cell anemia
sickle cell anemia, hereditary disease that destroys red blood cells by causing them to take on a rigid “sickle”......
sigmoidoscopy
sigmoidoscopy, diagnostic medical procedure that uses a flexible fibre-optic endoscope to examine the rectum and......
silicosis
silicosis, a chronic disease of the lungs that is caused by the inhalation of silica dust over long periods of......
silique
silique, any dry fruit that separates at maturity into two or four segments called valves, leaving a persistent......
Simpson, Sir James Young, 1st Baronet
Sir James Young Simpson, 1st Baronet was a Scottish obstetrician who was the first to use chloroform in obstetrics......
sinus squeeze
sinus squeeze, pain, inflammation, and possible bleeding of the membranes lining the sinus cavities in the head,......
sinusitis
sinusitis, acute or chronic inflammation of the mucosal lining of one or more paranasal sinuses (the cavities in......
Sjögren syndrome
Sjögren syndrome, chronic inflammatory disorder characterized by severe dryness of the eyes and mouth that results......
skin cancer
skin cancer, disease characterized by the uncontrolled growth of cells in the skin. Skin cancers are of two distinct......
skin disease
skin disease, any of the diseases or disorders that affect the human skin. They have a wide range of causes. Although......
skin squeeze
skin squeeze, effect on the skin of exposure to a pressure less than that of the surrounding environmental pressure.......
sleep
sleep, a normal, reversible, recurrent state of reduced responsiveness to external stimulation that is accompanied......
sleep apnea
sleep apnea, respiratory condition characterized by pauses in breathing during sleep. The word apnea is derived......
sleep paralysis
sleep paralysis, total inability to move for a very brief period that occurs as one is either falling asleep or......
sleeping sickness
sleeping sickness, disease caused by infection with the flagellate protozoan Trypanosoma brucei gambiense or the......
sleepwalking
sleepwalking, a behavioral disorder of sleep in which a person sits up and performs various motor actions, such......
smallpox
smallpox, acute infectious disease that begins with a high fever, headache, and back pain and then proceeds to......
smell
smell, the detection and identification by sensory organs of airborne chemicals. The concept of smell, as it applies......
smut
smut, plant disease primarily affecting grasses, including corn (maize), wheat, sugarcane, and sorghum, caused......
snakebite
snakebite, a wound resulting from penetration of the flesh by the fangs of a snake, especially a snake secreting......
snakeroot poisoning
snakeroot poisoning, illness in humans and grazing animals caused by trematol, a poisonous alcohol present in white......
snoring
snoring, a rough, hoarse noise produced upon the intake of breath during sleep and caused by the vibration of the......
snow mold
snow mold, plant disease that attacks cereals, forage grasses, and turf grasses in northern areas of North America,......
social anxiety disorder
social anxiety disorder (SAD), a type of anxiety disorder characterized by a fear of interacting with people, due......
sodium deficiency
sodium deficiency, condition in which sodium is insufficient or is not utilized properly. Sodium is an element......
soft palate
soft palate, in mammals, structure consisting of muscle and connective tissue that forms the roof of the posterior......
soil seed bank
soil seed bank, natural storage of seeds in the leaf litter, on the soil surface, or in the soil of many ecosystems,......
somite
somite, in embryology, one of a longitudinal series of blocklike segments into which the mesoderm, the middle layer......
sooty mold
sooty mold, plant disease characterized by splotchy black stains or coatings on leaves, stems, and fruit. The black......
sore mouth
sore mouth, viral disease of sheep and goats. The disease is characterized by the emergence of blisters, pustules,......
sound production
sound production, in animals, the initiation of sound as a means of information transmission. Sounds are termed......
soybean
soybean, (Glycine max), annual legume of the pea family (Fabaceae) and its edible seed. The soybean is economically......
spatial disorientation
spatial disorientation, the inability of a person to determine his true body position, motion, and altitude relative......
speech disorder
speech disorder, any of the disorders that impair human speech. Human communication relies largely on the faculty......
Spemann, Hans
Hans Spemann was a German embryologist who was awarded the Nobel Prize for Physiology or Medicine in 1935 for his......
sperm
sperm, male reproductive cell, produced by most animals. With the exception of nematode worms, decapods (e.g.,......
spermatogenesis
spermatogenesis, the origin and development of the sperm cells within the male reproductive organs, the testes.......
spina bifida
spina bifida, congenital cleft of the vertebral column, a form of neural tube defect...
spinal cord injury
spinal cord injury, any of various conditions caused by damage to the tract of nerves that extends from the base......
spine, curvature of the
curvature of the spine, any of a group of deviations of the normal spinal curvature, including scoliosis, lordosis,......
splenitis
splenitis, enlargement and inflammation of the spleen as a result of infection, parasite infestation, or cysts.......
splenomegaly
splenomegaly, enlargement of the spleen, the abdominal organ that serves as a temporary storage site for blood......
split-brain syndrome
split-brain syndrome, condition characterized by a cluster of neurological abnormalities arising from the partial......
spondylitis
spondylitis, inflammation of one or more of the vertebrae. Spondylitis takes several forms; the most widely occurring......
spondylolisthesis
spondylolisthesis, forward slipping of one of the vertebrae on the subjacent vertebra or on the sacrum, the triangular......
spondylosis
spondylosis, noninflammatory degenerative disease of the spine resulting in abnormal bone development around the......
spore
spore, a reproductive cell capable of developing into a new individual without fusion with another reproductive......
sporophyte
sporophyte, in plants and certain algae, the nonsexual phase (or an individual representing the phase) in the alternation......

Life Cycle, Processes & Properties Encyclopedia Articles By Title