Life Cycle, Processes & Properties, RES-SEX
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.
Life Cycle, Processes & Properties Encyclopedia Articles By Title
restless legs syndrome
restless legs syndrome, condition characterized by an uncontrollable urge to move the legs that usually appears......
retina
retina, layer of nervous tissue that covers the inside of the back two-thirds of the eyeball, in which stimulation......
retinitis pigmentosa
retinitis pigmentosa, group of hereditary eye diseases in which progressive degeneration of the retina leads to......
retinopathy
retinopathy, damage affecting the small blood vessels in the retina, the light-sensitive layer at the back of the......
retinopathy of prematurity
retinopathy of prematurity, disease in which retinal blood vessels develop abnormally in the eyes of premature......
Rett syndrome
Rett syndrome, rare progressive neurological disorder characterized by severe intellectual disability, autism-like......
Reye syndrome
Reye syndrome, acute neurologic disease that develops primarily in children following influenza, chicken pox, or......
rhabdom
rhabdom, transparent, crystalline receptive structure found in the compound eyes of arthropods. The rhabdom lies......
rheumatic fever
rheumatic fever, inflammatory disease of the heart, joints, central nervous system, and subcutaneous tissues that......
rheumatism
rheumatism, any of several disorders that have in common inflammation of the connective tissues, especially the......
rheumatoid arthritis
rheumatoid arthritis, chronic, frequently progressive disease in which inflammatory changes occur throughout the......
rhinitis
rhinitis, generic term for inflammation of the mucous tissue of the nose. Rhinitis may be allergic in origin and......
rhinophyma
rhinophyma, extensive overgrowth of the lower part of the nose. The sebaceous (oil-producing) glands seem to be......
rhizome
rhizome, horizontal underground plant stem capable of producing the shoot and root systems of a new plant. Rhizomes......
Rhodopsin
Rhodopsin, pigment-containing sensory protein that converts light into an electrical signal. Rhodopsin is found......
riboflavin
riboflavin, a yellow, water-soluble organic compound that occurs abundantly in whey (the watery part of milk) and......
Rice bacterial blight
Rice bacterial blight, deadly bacterial disease that is among the most destructive afflictions of cultivated rice......
rickets
rickets, disease of infancy and childhood characterized by softening of the bones, leading to abnormal bone growth......
Riedel thyroiditis
Riedel thyroiditis, extremely rare form of chronic inflammation of the thyroid gland, in which the glandular tissues......
Rift Valley fever
Rift Valley fever, viral infection of animals that is transmissible to humans and is caused by a type of Phlebovirus......
Rigor mortis
Rigor mortis, physiological process that occurs within hours after death, wherein muscle tissue stiffens. Rigor......
Riley-Day syndrome
Riley-Day syndrome, an inherited disorder occurring almost exclusively in Ashkenazic Jews that is caused by abnormal......
rinderpest
rinderpest, an acute, highly contagious viral disease of ruminant animals, primarily cattle, that was once common......
ringworm
ringworm, superficial skin lesions caused by a highly specialized group of fungi called dermatophytes that live......
Rocky Mountain spotted fever
Rocky Mountain spotted fever, form of tick-borne typhus first described in the Rocky Mountain section of the United......
rod
rod, one of two types of photoreceptive cells in the retina of the eye in vertebrate animals. Rod cells function......
Romer, Alfred Sherwood
Alfred Sherwood Romer was a U.S. paleontologist widely known for his concepts of evolutionary history of vertebrate......
roseola infantum
roseola infantum, infectious disease of early childhood marked by rapidly developing high fever (to 106Ā° F) lasting......
Rot
Rot, any of several plant diseases, caused by any of hundreds of species of soil-borne bacteria, fungi, and funguslike......
rotational stress
rotational stress, physiological changes that occur in the body when it is subjected to intense gyrational or centrifugal......
rotator cuff injury
rotator cuff injury, damage to the network of muscles and tendons that stabilize and support the shoulder. This......
Roux, Wilhelm
Wilhelm Roux was a German zoologist whose attempts to discover how organs and tissues are assigned their structural......
rubella
rubella, contagious viral disease that runs a mild and benign course in most people. Although rubella is not usually......
Rust
Rust, plant disease caused by more than 7,000 species of fungi of the phylum Basidiomycota. Rust affects many economically......
saccade
saccade, fast, intermittent eye movement that redirects gaze. Saccades may involve the eyes alone or, more commonly,......
sadism
sadism, a habit or practice of deriving sexual gratification from the infliction of pain or suffering on another......
sadomasochism
sadomasochism, deriving pleasure, often of a sexual nature, from the infliction of physical or psychological pain......
saliva
saliva, a thick, colourless, opalescent fluid that is constantly present in the mouth of humans and other vertebrates.......
salivary gland
salivary gland, any of the organs that secrete saliva, a substance that moistens and softens food, into the oral......
salmonellosis
salmonellosis, any of several bacterial infections caused by certain species of Salmonella, important as the cause......
Sanfilippoās syndrome
Sanfilippoās syndrome, rare hereditary (autosomal recessive) metabolic disease characterized by severe mental retardation.......
sarcoidosis
sarcoidosis, systemic disease that is characterized by the formation of granulomas (small grainy lumps) in affected......
sarcoma
sarcoma, tumour of connective tissue (tissue that is formed from mesodermal, or mesenchymal, cells). Sarcomas are......
sarin
sarin, synthetic organophosphate compound that is highly toxic to the nervous system. Exposure to sarināwhich is......
SARS
SARS, highly contagious respiratory illness characterized by a persistent fever, headache, and bodily discomfort,......
satiety
satiety, desire to limit further food intake, as after completing a satisfying meal. The hypothalamus, part of......
Scab
Scab, in botany, any of several bacterial or fungal plant diseases characterized by crustaceous lesions on fruits,......
scab
scab, in pathology, secondary skin lesion composed of dried serum, blood, or pus. See...
scabies
scabies, skin inflammation accompanied by severe itching, particularly at night, caused by the itch mite (Sarcoptes......
scar
scar, mark left on the skin after the healing of a cut, burn, or other area of wounded tissue. As part of the healing......
scarlet fever
scarlet fever, acute infectious disease caused by group A hemolytic streptococcal bacteria, in particular Streptococcus......
scavenger
scavenger, animal that feeds partly or wholly on the bodies of dead animals. Many invertebrates, such as carrion......
Scheieās syndrome
Scheieās syndrome, uncommon hereditary metabolic disease characterized by clawing of the hands, corneal clouding,......
schemochrome
schemochrome, any one of many colourless, submicroscopic structures in organisms that serve as a source of colour......
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 āburnedā 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
seed, the characteristic reproductive body of both angiosperms (flowering plants) and gymnosperms (e.g., conifers,......
- Introduction
- Gymnosperm, Embryo, Structure
- Size, Predation, Protection
- Animal Dispersal, Germination, Fruits
- Wind Dispersal, Pollination, Germination
- Water Dispersal, Germination, Viability
- Germination, Embryo, Plant Growth
- Afterripening, Stratification, Temperature
- Photosynthesis, Germination, Dispersal
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......
sensory reception, human
human sensory reception, means by which humans react to changes in external and internal environments. Ancient......
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......
severe fever with thrombocytopenia syndrome
severe fever with thrombocytopenia syndrome (SFTS), rapidly progressing tick-borne viral disease characterized......
Sex
Sex, the sum of features by which members of species can be divided into two groupsāmale and femaleāthat complement......
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 color,......
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......