The genes in a population give forth the genetic variability across a population (genotypes). In addition, occasional mutations of these genes in a population increase this genetic variability. Hovever, natural selection only favours reproduction of individuals with genes that are favourable in the environment/habitat. Therefore, natural selection has no foresight but is rather pegged on being an ‘opportunistic’ process.
Answer:
A. Populations were separated through geographical isolation.
Explanation:
<h2>C) option is correct </h2>
Explanation:
- Glomerular filtration is the process which kidneys uses to filter excess fluid and waste products out of the blood into the urine collecting tubules of the kidney, so that they may be eliminated from the body
- The rate at which kidneys filter blood is called the glomerular filtration rate
- The main driving force for the filtering process, or outward pressure is the blood pressure as it enters the glomerulus, this is counteracted to some extent by inward pressure due to the hydrostatic pressure of the fluid within the urinary space, and the pressure generated by the proteins left in the capillaries that tend to pull water back into the circulatory system (colloidal osmotic pressure)
- The net filtration pressure is the outward pressure minus the inward pressure
Answer:
c) melatonin
Explanation:
Melatonin its a hormone formed by the pineal gland, which regulates an individual wake cycles and sleep. Jetlag alters the hormone function leading to an alteration with the body clock of the persom.
Jetlag is a sleep disorder common to those who travel swiftly over several time zones. It is not a permanent sleep disorder. Its due to the body's internal clock lacking sync with cues generated in a different time zone, Cues may be due to light exposure and how often the person eats.
A basic factor on ones internal clock is sunlight. It controls the regulation of melatonin which aid in synchronizing cells in the body.
Specific cells of the tissue at retina moves the light signals the thypothalamus.
At night, the hypothalamus signal to the pineal gland to produce melatonin. At daylight hours, the reverse is the case.
The correct answer is option (d) atmosphere.
Fossil fuels are the hydrocarbons formed in the geological past, derived from the remains of dead plants and animals. They include the coal, fuel gas and the natural gas. The burning of fossil fuels is one of the greatest contributor of carbon dioxide being added to the atmosphere. This results in the pollution of air in the atmosphere resulting in the formation of smog. Carbon dioxide being a green house gas, affects the atmosphere and causes green house effect leading to global warming and climate changes.
The burning of fossil fuels affects the geosphere, biosphere and hydrosphere indirectly due to its primary direct effect on the atmosphere. Thus, atmosphere is directly affected by the burning of fossil fuels.
