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.
The answer is catastrophism.
Catastrophism is a theory explaining that the Earth has been affected by sudden catastrophes which created its geological features. Some of the proposed catastrophes is a global flood followed by an uplifting of some rock which happened sudden, in a short period of time. It is opposite theory to uniformitarianism which explains that the Earth was formed in slow changes.
Carbon is an essential to all living forms on earth, whether they need carbon intake to help produce food or release carbon for breathing. All plants and animal life need carbon, without it would be impossible for life on earth.
Answer:
Boiling point.
Explanation:
This is because when water boils, it is changing from a liquid to a gas. This is a state change/physical change.
I hope I helped!
Answer:
The statement C that says ''is derived from the inner cell mass'' is false.
Explanation:
The trophoblast is a structure composed of a set of cells (cytotrophoblast and syncytiotrophoblast), which are shaping the outer layer surrounding a blastocyst, during the earliest stages of embryonic development that mammals pass.
The trophoblast provides nutritive molecules to the developing embryo and facilitates its implantation to the uterine wall due to its ability to erode the tissues of the uterus, that is, it is responsible for making it possible for the embryo to be implanted in the uterine endometrium. Thus, the blast can join the cavity formed by the uterine wall, where it will absorb nutrients from the fluid from the mother.
During the third week, embryonic development includes the development of the trophoblast. At the beginning, the primary villi are formed by the internal cytotrophoblast which is surrounded by the outer layer of syncytiotrophoblast. Then, the cells found in the embryonic mesoderm are directed to the primary villous in the third week of gestation and when it ends, the mesodermal cells begin to be singled out to form blood vessel cells.
