1) Are they reliable?
2) Are they relevant?
3) Are they recent?
4) Are they sound resources?
5) Are they a primary source?
6) Are they a secondary source?
Answer:
The placenta is the temporary association of fetus and maternal tissue. It is meant for nutrition and transport of different substances.
Explanation:
The placenta is a temporary association of fetal and maternal tissues. The placenta is formed from the trophoblast of the blastula. These trophoblasts form chorionic villi which later forms the placenta. The chorion and allantois also take part in the formation of the placenta. Hence, the human placenta is known as the chorioallantoic placenta. The process of formation of the placenta is known as placentation.
The placenta has several functions but the major function is to provide nutrition to the fetus. The developing fetus gets nutrition from the mother's body by the placenta. The placenta provided with blood vessels which help in the transportation of different substances. It also helps in gas exchange between the mother and baby. Thus it plays a vital role in fetal respiration. The metabolic wastes diffuse through the placenta. Placenta also stores fat, glycogen, which participates in protein metabolism.
Crossing over occurs at the four-strand stage when two homologous chromosomes, each consisting of a pair of sister chromatids, are paired. Each crossover involves just two of the four strands and generates two recombinant strands.
Hope this helps!
A seismometer is used to measure the motion in the ground caused by earthquakes, volcanoes, or explosives.
Most likely, it would effect many trees depending on the rate of infection and how much of this microorganism is released to the environment. I hope that helped :)