Explanation:
In the majority of cases, the extra copy of chromosome 21 comes from the mother in the egg.
In a small percentage (less than 5%) of cases, the extra copy of chromosome 21 comes from the father through the sperm.
In the remaining cases, the error occurs after fertilization, as the embryo grows.
Answer:
There are only 2 possible genotypes for the mother, FF and Ff.
Explanation:
Because it is an autosomal inheritance, this case F will be the dominant allele and f the recessive allele, where f produces Fatty acid metabolism disorder. If the mother does not possess the disorder, she must possess at least one dominant allele for that specific gene. However, for the other allele, we cannot assure that it is dominant, since it can be recessive and not express itself either in her or in the offspring, because of the father we also only know his dominant allele.
Answer:
The earliest known life-forms are putative fossilized microorganisms, found in hydrothermal vent precipitates, that may have lived as early as 4.28 Gya (billion years ago), relatively soon after the oceans formed 4.41 Gya, and not long after the formation of the Earth 4.54 Gya.
Explanation:
The disadvantage of having imformation at your fingertips is that not all of information could be true but only mere ideas or theories and that having alot of information can be overwhelming to the point where you can process so much information you might forget about the important things you come across for some propaganda trying to get your attention
