The amplitude measures the amount of displacement in a longitudinal wave.
Answer: Many pathogenic fungi are parasitic in humans and are known to cause diseases of humans and other animals. In humans, parasitic fungi most commonly enter the body through a wound in the epidermis (skin). Such wounds may be insect punctures or accidentally inflicted scratches, cuts, or bruises. One example of a fungus that causes disease in humans is Claviceps purpurea, the cause of ergotism (also known as St. Anthony’s fire), a disease that was prevalent in northern Europe in the Middle Ages, particularly in regions of high rye-bread consumption. The wind carries the fungal spores of ergot to the flowers of the rye, where the spores germinate, infect and destroy the ovaries of the plant, and replace them with masses of microscopic threads cemented together into a hard fungal structure shaped like a rye kernel but considerably larger and darker. This structure, called an ergot, contains a number of poisonous organic compounds called alkaloids. A mature head of rye may carry several ergots in addition to noninfected kernels. When the grain is harvested, much of the ergot falls to the ground, but some remains on the plants and is mixed with the grain. Although modern grain-cleaning and milling methods have practically eliminated the disease, the contaminated flour may end up in bread and other food products if the ergot is not removed before milling. In addition, the ergot that falls to the ground may be consumed by cattle turned out to graze in rye fields after harvest. Cattle that consume enough ergot may suffer abortion of fetuses or death. In the spring, when the rye is in bloom, the ergot remaining on the ground produces tiny, black, mushroom-shaped bodies that expel large numbers of spores, thus starting a new series of infections.
Answer:
In the given case, both the parents exhibit black color with normal vision, however, the progenies from these parents exhibit black color with one exhibiting brown color, while one is black in color but exhibiting a condition associated with vision known as PRA. This indicates that both these parents are heterozygous and the brown color and PRA are the recessive traits.
The progenies showing black normal vision, brown normal vision and black with PRA, indicates that the alleles for these genes have got segregated autonomously of each other.
Lack of proper sanitation facilities and water drainage system can cause merging of fresh water with the sewage and allow bacteria, viruses and various other microbes to enter the water supply. This causes infectious diseases.
