Answer:
The correct answer is option d.
Explanation:
Based on the given question, the genotype of the male parent is aa, the genotype of the female parent is Aa, and the genotype of the offspring is AAa, showing trisomy characteristics. In the given case, the existence of two A chromosomes shows that the chromosomes non-disjunction at the time of gametogenesis have taken place in the female as she is the only one possessing A allele. Hence, it can be concluded that the disjunction is maternal in characteristic.
The duplication of chromosomes takes place at the time of the S-phase of meiosis. Thus, after going through S-phase, the karyotype of the cell will be AAaa (maternal gametogenesis), this set of the chromosome is termed as homologous pair, and the pair of AA or aa is termed as sister chromatids.
The meiotic disjunction takes place in two phases. First, in meiosis I disjunction, in this separation of homologous chromosomes takes place, that is, the maternal cell AAaa get differentiated into aa and AA daughter cells. Secondly, in meiosis II disjunction, the separation of sister chromatids takes place into two independent chromosomes, that is, the formation of two cells each comprising chromosome A from the AA cell and the formation of two cells each with chromosome a from the aa cell.
Thus, the phenomenon of non-disjunction would have taken place at the time of meiosis II in the case of a female gamete to exhibit two A chromosomes. Hence, the correct answer is option d.
These changes can be natural, such as through variations in the solar cycle.
<h3>Climate history</h3>
Clam shells
2. 800,000 years ago
Ice cores
1. 150 million years ago
Oldest rocks in the world
5. 3.8 billion years ago
Tree cores
3. 10,000 years ago
Ocean sediments
4. 200 million years ago
With this information we can conclude that these changes may be natural, such as through variations in the solar cycle. But since 1800, human activities have been the main driver of climate change, mainly due to the burning of fossil fuels like coal, oil and gas.
Learn more about Climate in brainly.com/question/885982
<span>Chromatids (either of the 2 chromosome strands that separate during mitosis) would not be fully developed.</span>
[Ar] 4s1 is the correct answer
There's been a lot of bad news for polar bears recently. In 2007, for example, scientists reported that if global warming continues unabated, the population could drop two-thirds by 2050.
