In nature there are two categories of microorganisms as relating to health. Microorganisms that are considered harmful to humans are called pathogens and these cause disease. Examples include bacteria such as streptococcus which cause sore throat and salmonella which cause typhoid disease.
There are some microorganisms which are helpful to man and they live mostly on the skin of man or in his gut and are mostly bacteria. They are collectively called bacterial normal flora.
In man the normal bacterial flora of the skin include staphylococcus found on dry skin, cornybacteria found in moist skin sites and propionibacteria in the sebaceous sites (head, neck, trunk) of the body. Normal bacterial flora of the gut include Escherichia coli.
One of the major function of bacterial flora is actually to protect our bodies by competing for space with pathogens preventing them from gaining a foothold in our bodies.
22 year solar cycle is characterized by a variation in the number of sunspots and a reversal of the polarity of the Sun as a whole.
What are sunspots?
Sunspots are caused by disturbances in the Sun's magnetic field welling up to the Sun's visible surface.
Sunspot are region of the earth that are more darker than other surfaces. They have a reduced temperature.
If sunspots are active, more solar flares will result creating an increase in geomagnetic storm activity for Earth.
Here, the sun's magnetic field changes polarity approximately every 11 years. So, for reversal polarity of the sun, 22 year solar cycle is characterized by a variation in the number of sunspots and a reversal of the polarity of the Sun as a whole.
Learn more about sunspots here:
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Answer:
this vehichle has 896,000 jules of energy
Explanation: KE=1/2mv squared, KE is Kinetic energy. m is mass and v is velocity
Answer:
16km/h
Explanation:
Vt=20km/h ---train speed
Vd=4km/h
Donas speed relative to ground is:
Vrd=Vt-Vd
Donas is moving in opposite direction of train .
Vrd=20km/h-4km/h
Vrd=16km/h
C the runners feet pushing against the ground describes the acceleration toward the finish line
