<span>Cigarettes were not outlawed when the dangers were first noticed, because their lobby is very strong. Their industry is gaining lots of money by selling cigarettes, so they didn't want to stop producing them. Instead, they settle for reducing the nicotine and inventing new forms of cigarettes (the electrical ones for example).</span>
Answer:
The correct option is;
a. 11.21
Explanation:
The chemical equation for the reaction is;
NH₄OH ↔ NH₄⁺ + OH⁻
At the start of the reaction, we have;
NH₄OH ↔ NH₄⁺ + OH⁻
I
0.15 0 0
C 0.15 - x +x +x
The
= 1.78 × 10⁻⁵
Therefore, we have;
1.78 × 10⁻⁵ = [NH₄⁺][OH⁻]/NH₄OH = x²/(0.15 - x)
Which gives;
(0.15 - x) 1.78 × 10⁻⁵ = x²
x² + 1.78 × 10⁻⁵x - 2.67× 10⁻⁶ = 0
Factorizing the above equation online, gives;
(x + 0.00164294)(x - 0.00162514) = 0
Therefore;
x = -0.00164294, or x = 0.00162514
We use the positive result, which is x = 0.00162514 = 1.62514 × 10⁻³ = [OH⁻]
Therefore;
pOH = -log[OH⁻] = -log(0.00162514) = 2.789
pH + pOH = 14
Therefore;
pH = 14 - pOH = 14 - 2.789 ≈ 11.21089
The pH of a 0.15 M NH₄OH solution with
= 1.78 × 10⁻⁵ = 11.21.
The pH of a 0.15 M NH₄OH solution with
= 1.78 × 10⁻⁵ is approximately 11.21
Best Answer:<span> </span><span>Before DNA, taxonomists use detailed comparative anatomy. As Louis Dollo, one of the greatest anatomists of all time, points out, evolution is irreversible.
Dollo's principle states:
"An organism is unable to return, even partially, to a previous stage already realized in the ranks of its ancestors.". According to this hypothesis a structure or organ that has been lost or discarded through the process of evolution will not reappear in exactly the same form in that line of organisms."
It means, that, no matter how closely two organisms may resemble one another, the products of convergent evolution can never resemble one another in every single detail. By examining them closely, evidence of separate ancestry will always reveal themselves. Dollo's principle has served taxonomy very well, although some taxonomists have unwisely abandoned comparative anatomy and rely instead on superficial similarity. They claim, for example, that bird hands must be the same as theropod hands because both of them have 3 fingers. Comparative anatomists, OTOH, would point out that bird hands have fingers 2-3-4 because of evidence from developmental biology and the 3 fingers of theropod hands are 1-2-3 based on fossil evidence, since primitive theropods such as Eoraptor and Herrerasaurus have vestigial fingers 4 and 5. Therefore, using Dollo's principle, we have determined that birds and theropods have evolved their 3 fingered hands independently of each other from a common ancestor with a 5 fingered hand.
Finally, to answer the question of whether snakes and worms share a recent common ancestor, we apply Dollo's principle by examining both animals in detail. Snakes have a vertebral column. They have jaws. Snakes have a lung and they have scales made of beta keratin. These structures are absent from worms. OTOH, these same structures are found only in vertebrates, but not in all vertebrates. The particular subgroup of vertebrates that have these uniquely shared characters are in fact the reptiles. Snakes therefore are reptiles, not worms. Further, since snakes and lizards share the unique character of paired hemipenes, snakes are in fact close relatives of lizards. Using Dollo's principle to study worms, we can also determine that not all worms share a recent common ancestor either. Some worms for example, have a coelom, but some have a pseudocoelom while others, such as the flat worms, have no coelom at all. Using comparative anatomy, it has been determined that annelid worms are in fact more closely related to arthropods and molluscs than they are to the round or nematode worms.
Dollo's principle has in fact resulted in a highly stable and useful classification. However, many contemporary taxonomists are either ignorant of it or disdains its use. The result is taxonomic chaos generated by those who fail to realize how powerful and useful Dollo's principle really is.</span>
Answer:
The letter B is the right answer.
Explanation:
The main objective of the hardin and Weinberg equilibrium is to determine how the allelic frequencies change within a population.
In 1908, Godfrey H. Hardy (1877-1947) and the German physician, Wilhem Weinberg, proposed that if no evolutionary factors act on a given population, the frequencies of their alleles would remain unchanged for several generations. This proposal became known as Hardy-Weinberg's Law (or theorem) or principle of gene balance.
According to this law, the necessary conditions for a population to reach equilibrium are:
a) The population must be large, so that all possible intersections occur.
b) The population must be panmatic (from the Greek pan, all, and from the Latin miscere, mix), that is, the crossings must be carried out randomly, without preconditions.
Within these conditions, without mutation, migration or selection, there will be a genetic balance. Over the generations, genes will not change.
Answer:
their blood cell vessels will consume Themselves. therefore losing life