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.
Answer:
non-specific system
Explanation:
The non-specific immune system is the system that works 24 hours a day, 7 days a week and protects you, regardless of the organism you encounter. This system is composed of the general defenses of the organism that work continuously, creating barriers that protect the body from the entry of any pathogen or foreign substance. This system is composed of T cells, which are true killers of pathogens and which guarantee efficient and complete safety.
So, the Sun's light takes about 8.3 minutes to reach us. This means that we always see the Sun as it was about 8.3 minutes ago. ... The nearest large galaxy to us, Andromeda, is 2.5 million light-years away. So, we see Andromeda as it was 2.5 million years in the past.
1. The main aim of the Human Genome Project was to determine the DNA Sequence of every human gene.
2. Variation in skin colour is an example of polygenic inheritance
This Human Karyotype is unusual because it has an extra chromosome at chromosome 21.
Klinefelters syndrome is shown in the second figure
Explanation:
1. The Human Genome Project's main goal was to sequence all the 30,000 genes and 3 million base pairs in their makeup for the early detection of diseases, gene therapy and molecular level studies.
2. Human skin colour is determined by the pigment melanin. The Dominant allele is responsible for dark colours as it produces more melanin. The melanocortin 1 receptor (MC1R) gene and Tyrosinase enzyme codes for the human skin colour. Polygenic inheritance are the traits which are controlled by one or more genes.
<u>figures:</u>
<u>The extra chro</u>mosome at the 21st chromosome pairs is called trisomy 21 or Down's Syndrome. It is due to the abnormal cell division/meiosis resulting in an extra X chromosome. This leads to thechanges the in physical development of the individual.
Klinefelter's Syndrome: There are 47 chromosomes and 2 or more X chromosomes in this syndrome of males. The resulting male suffering from Klinefelter would be sterile and have poorly developed testicles.
Answer:
A. The birth rate would likely increase.
Explanation:
if the quantity is analyzed in any time interval, the quantity at any given moment is the product of the previous quantity
