<span>The order of impulse conduction in the heart, from beginning to end, is </span><span>SA node, AV node, bundle of His, bundle branches, and Purkinje fibers.
SA node, or the sinus node, is the heart's natural pacemaker. AV node, or the atrioventricular node, spreads electrical impulses from the atria to the ventricles. The bundle of His, as well as bundle branches, are a part of the electrical conduction system of the heart. Purkinje fibers send nerve impulses through the heart.
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Answer:
E) a natural mutagen.
Explanation:
Aflatoxin is a toxin byproduct produced by the fungi especially Aspergillus molds which grows attached to the roots of various crops like the peanuts, wheat and many others.
The aflatoxin is considered a carcinogen and a mutagen as it causes certain changes in the structure of DNA. The aflatoxin mainly affects the liver and causes a mutation in the genes of the liver and since the aflatoxin is produced naturally by the molds, therefore, is considered a natural mutagen.
Thus, option-E is correct.
The progenies of the dragons with strong fire and dragon with no fire will be dragons with fire at medium rate.
<h3><u>Explanation:</u></h3>
Incomplete dominance is the phenomenon when two different alleles are present in a same organism gives a mixed type of phenotype which isn't similar to any characters of the parents.
In case of the dragons, the genotype of the dragons with strong fire = FF.
The genotype of the dragons with no fire = F'F'.
So the gametes produced by the dragon with strong fire is F and that by the dragons with no fire is F'.
So the dragons produced as a progeny = FF'.
As this gene shows incomplete dominance, so both the characters will be mixed and present as a mixed character. So the offsprings will be moderately fire breathing.
Hello Gangt181, The current increase of carbon dioxide in the atmosphere is as a result
of human activities that began in the late 1700s. This period sparked
the beginning of the Industrial Revolution and this is when we began to
use fossil fuels. The burning of fossil fuels coupled with widespread
global deforestation has led to a rise in CO2. Excess carbon dioxide in
the oceans causes it to become more acidic. This acidity will affect
marine species with shells like mussels and lobsters.
"These" should be referring to Alkali Metals.
They include metals such as Lithium, Sodium, Potassium etc.
They're classified as Group I elements because they all have one outmost shell electrons. This is why these metals are so reactive because they only need to lose one electron in order to achieve the octet of electrons (or duplet for Lithium), which means complete outmost shell electrons (2 or the 1st shell, others are 8).
The reason why they're especially reactive to Halogens (Group VII) elements are that Halogens have 7 outmost shell electrons, which only needs one more electron in order to get to the octet of electrons. So, if an Alkali metal reacts with a Halogen, the metal would give one of their electrons to the Halogen, that way, both of the elements can have an octet of electrons (or duplet).
