Answer:
Earth formed around 4.54 billion years ago, approximately one-third the age of the universe, by accretion from the solar nebula. Volcanic outgassing probably created the primordial atmosphere and then the ocean, but the early atmosphere contained almost no oxygen.
Explanation:
Answer:
Hepato- and nephrotoxicity of fluoride have been demonstrated in animals, but few studies have examined potential effects in humans. This population-based study examines the relationship between chronic low-level fluoride exposure and kidney and liver function among United States (U.S.) adolescents. This study aimed to evaluate whether greater fluoride exposure is associated with altered kidney and liver parameters among U.S. youth.
This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (2013–2016). We analyzed data from 1983 and 1742 adolescents who had plasma and water fluoride measures respectively and did not have kidney disease. Fluoride was measured in plasma and household tap water. Kidney parameters included estimated glomerular filtration rate (calculated by the original Schwartz formula), serum uric acid, and the urinary albumin to creatinine ratio. Liver parameters were assessed in serum and included alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, blood urea nitrogen, gamma-glutamyl transferase, and albumin. Survey-weighted linear regression examined relationships between fluoride exposure and kidney and liver parameters after covariate adjustment. A Holm-Bonferroni correction accounted for multiple comparisons.
The average age of adolescents was 15.4 years. Median water and plasma fluoride concentrations were 0.48 mg/L and 0.33 μmol/L respectively. A 1 μmol/L increase in plasma fluoride was associated with a 10.36 mL/min/1.73 m2 lower estimated glomerular filtration rate (95% CI: −17.50, −3.22; p = 0.05), a 0.29 mg/dL higher serum uric acid concentration (95% CI: 0.09, 0.50; p = 0.05), and a 1.29 mg/dL lower blood urea nitrogen concentration (95%CI: −1.87, −0.70; p < 0.001). A 1 mg/L increase in water fluoride was associated with a 0.93 mg/dL lower blood urea nitrogen concentration (95% CI: −1.44, −0.42; p = 0.007).
Fluoride exposure may contribute to complex changes in kidney and liver related parameters among U.S. adolescents. As the study is cross-sectional, reverse causality cannot be ruled out; therefore, altered kidney and/or liver function may impact bodily fluoride absorption and metabolic processes.
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Answer:
The correct answer is "qualitative, discrete".
Explanation:
A qualitative or discrete trait is defined as a characteristic that have no intermediate features, and is often the result of genetic alleles at a single locus. For instance, if the form the seeds of pea could be either round or wrinkled, but not with intermediate forms. This is the case of the fly that has white or red eyes, but does not have pink eyes or other colors in between.
<em>The function of skeletal muscles is to control the movement of internal organs. The skeletal muscle pulls the tendons attached to the bones.</em>
Antibiotic used include kenamycin, ampicillin and tetracycline. This is useful to determine if and which bacteria took up the plasmid as they were supposed to during the process of recombination. Host bacteria are normally killed by these antibiotics. If the recombinant plasmids were taken up by the bacteria, plasmid may have contained a DNA gene for resisting the effects of one or more antibiotics. Host bacteria are placed in a growth medium containing an antibiotic to which they have a resistant gene in their recombinant plasmid DNA survivor. If they havent taken the plasmid they die.
