Answer:
Genetic variation is essential for natural selection because natural selection can only increase or decrease frequency of alleles that already exist in the population. Genetic variation is caused by: mutation
Explanation:
to rearrange its configuration to result in a complete outer shell or have a stable octet.
The method of the following issues that cause homeostatic imbalances:
1. Gallstones: The precipitation of excess bladder cholesterol into solid crystals is a prerequisite for cholesterol bladder formation, which is caused by disturbed bladder homeostasis. ... We have previously seen that bile and bladder osteopontin (OPN) levels are decreased in gallbladder patients.
2. Ulcers: Gastric bleeding is a major complication of peptic ulcer. Infection by H. Pylori leads to an imbalance of body iron homeostasis, as the increasing demand for iron is the same. Like other types of bacteria, iron is also essential for H growth.
3. Dehydration: If we are low on water, our bodies reduce the sweat and urine we produce to reduce fluid. Most of these reactions are effective under normal conditions and can restore water levels to homeostasis.
4. Diarrhoea: Bile acids, bacterial enterotoxins and neoplasm-derived secrets disrupt this homeostatic state, for example, leading to diarrhea. ... Different infectious organisms (eg bacteria, protozoa, viruses) use different mechanisms to cause intestinal infection and dysentery.
5. Cirrhosis: Disturbed volume homeostasis in patients with cirrhosis of the liver. ... Patients with moderately developed cirrhosis often show a characteristic circulatory disturbance, including arterial hypotension and urinary sodium retention by the kidney, which may lead to edema and ascites.
6. Cancer: Cancer, in this example, breaks down in the balance between cell growth and cell death. The gene that over-expresses anti-apoptotic genes and rejects pro-apoptotic genes is not understood, and it is often unknown why homeostatic equilibrium is lost (perhaps another term for carcinogenesis).
Answer:
Most water systems test for lead as a regular part of
water monitoring. These tests give a system-wide
picture, but do not refl ect conditions at a specifi c
household faucet.
If you want to know if your home’s drinking water
contains unsafe levels of lead, have your water tested.
Testing is the only way to confi rm if lead is present or
absent.
Some faucet and pitcher fi lters can remove lead from
drinking water. If you use a fi lter to remove lead, be
sure you get one that is certifi ed to remove lead by NSF
International.