Jill is heterozygous for gene A and is going to have a child with Jack, who is homozygous recessive for gene A. Which of the fol
lowing offspring genotypes could result from fertilization of a normal haploid sperm with an egg that had undergone nondisjunction in meiosis I? Hint: It may be helpful to sketch the outcome of nondisjunction to solve this problem. Options are:
Jill (mother) is heterozygous for gene A --------- i.e Jill = Aa
Jack (father) who is homozygous recessive for gene A-------- i.e Jack = aa
Now if both cross and fertilization occurs, we have:
a Aa aa
a Aa aa
The offsprings are (Aa, Aa, aa, aa)
Nondsijunction is the inability of homologous chromosomes to seperate properly during cell division. Now, we were told that this fertilization undergone nondisjunction in meiosis 1. Hence, both homologous chromosome move into the same daughter cells instead of different daughter cells because separation of homologous chromosome does not occur properly.
Therefore the result of these fertilization of a normal haploid sperm with an egg that had undergone nondisjunction in meiosis yields offspring with genotypeAa of their Mother (Jill).
<span>Primary succession is the establishment of a community in an area with no soil, while secondary succession is the establishment of a new community in an existing ecosystem that was disturbed by some catastrophic event.
In the electron transport chain, there are multiple reduction-oxidation reactions that generate a proton gradient between the inner membrane space and the mitrocondrial matrix. The most direct source of energy is the last complex of the electron transport chain wherein the proton gradient goes to the complex called the ATP synthase and produce ATP from ADP and inorganic phosphate.