Science And Technology

Urinary tract   infection A urinary tract infection (UTI) is an infection that affects part of the urinary tract. 1] When it affects the lower urinary tract it is known as a bladder infection (cystitis) and when it affects the upper urinary tract it is known as kidney infection (pyelonephritis).  Symptoms       from a lower urinary tract include pain with urination, frequent urination, and feeling the need to urinate despite having an empty bladder.  Symptoms of upper urinary track infection Symptoms  of a kidney infection include fever and flank pain usually in addition to the symptoms of a lower UTI.   Rarely the urine may appear bloody. In the very  old and the very young, symptoms may be vague or non-specific. Urinary tract infection Synonyms Acute cystitis, simple cystitis, bladder infection, symptomatic  bacteria referred to as a bladder infection. The most common symptoms are burning with ...

 A. External or Environmental factors 1. Atmospheric Humidity: The rate of transpiration is roughly inversely proportional to atmospheric humidity. As the outward diffusion of water vapors through stomata is in accordance with the law of simple diffusion, the rate of transpiration is greatly reduced when the atmosphere is very humid. As the air becomes dry, the rate of transpiration also increases proportionately. TEMPERATUR With the increase in atmospheric temperature, the rate of transpiration also increases. This is not only because evaporation occurs quickly in warmer air but also because warm air is capable of holding more water vapors than the cold air. 3. Light: The rate of transpiration is roughly proportional to the intensity of light. The mode of action of light is both direct and indirect. The increasing light intensity raises the temperature of leaf cells and thus increases the rate at which liquid water is transformed into vapors. Direct effect of l...

       Transpiration   Transpiration   is the process of  water  movement through a  plant  and its  evaporation  from aerial parts, such as  leaves ,  stems  and  flowers . Water is necessary for plants but only a small amount of water taken up by the roots is used for growth and metabolism. The remaining 97–99.5% is lost by transpiration and  guttation .  Leaf surfaces are dotted with pores called  stomata ,\ The stomata are bordered by  guard cells  and their stomatal accessory cells (together known as stomatal complex) that open and close the pore.  Transpiration occurs through the stomatal apertures, and can be thought of as a necessary Why do plants need to do transpiration? The water, warmed by the sun, turns into vapor (evaporates), and passes out through thousands of tiny pores (stomata) mostly on the underside of the leaf surface. This  is transpirat...

Growth and Development THE VEGETATIVE PHASE OF DEVELOPMENT  begins with embryogenesis, but development continues throughout the life of a plant. Plant developmental biologists are concerned with questions such as, How does a zygote give rise to an embryo, an embryo to a seedling? How do new plant structures arise from preexisting structures? Organs are generated by cell division and expansion, but they are also composed of tissues in which groups of cells have acquired specialized functions, and these tissues are arranged in specific patterns. How do these tissues form in a particular pattern, and how do cells differentiate? What are the basic principles that govern the size increase (growth) that occurs throughout plant development? Understanding how growth, cell differentiation, and pattern formation are regulated at the cellular, biochemical, and molecular levels is the ultimate goal of developmental biologists. Such an understanding also must include the genetic basis of dev...

WATER ABSORPTION BY ROOTS Intimate contact between the surface of the root and the soil is essential for effective water absorption by the root. This contact provides the surface area needed for water uptake and is maximized by the growth of the root and of root hairs into the soil. Root hairs are microscopic extensions of root epidermal cells that greatly increase the surface area of the root, thus providing greater capacity for absorption of ions and water from the soil. When 4-month-old rye ( Secale ) plants were examined, their root hairs were found to constitute more than 60% of the surface area of the roots Water enters the root most readily in the apical part of the root that includes the root hair zone. More mature regions of the root often have an outer layer of protective tissue, called an exodermis or hypodermis , that contains hydrophobic materials in its walls and is relatively impermeable to water. The intimate contact between the soil and the root surface is easily rup...