The answer to this question would be: excess fluoride intake
The toothpaste has a high amount of fluoride and will increase the blood fluor level. Excess fluoride intake in children can cause fluorosis which was the brown staining of teeth because fluor is deposited in the growing teeth. Fluorosis can happen in children with <8-year ages.
Answer:
Lacks the right key to unlock many cells.
Explanation:
Avian influenza (H5 N1) rarely transmitted from poultry to humans because it lacks the right key to unlock many cells in the upper respiratory tract so due to this action the virus is rarely transmitted to humans. Sometimes it is lethal to humans due to absence of antibodies for this type of virus. It is rarely spread from person to person due to inability to enters the other human body.
Answer:
The answer is letter A.
Explanation:
During anaerobic respiration, lactate levels increase when muscles cells need more energy, however muscles cells eventually fatigue, thus athletes should modify their activities to increase aerobic respiration.
Answer: c not all cells have a nucleus (prokaryotic cells don’t)
Explanation:
1/4 or 25% will have the homozygous recessive genotype. 25% will have the homozygous dominant phenotype. 50% will be heterozygous. We would use a punnet square to figure this out. I’ve attached a picture of one to help you