The correct answer is option Observations can be made from outside the "system".
The study of the plate tectonics allows the observation of the movement of the plate tectonics. These observation can be study to determine the pattern of the movement from outside the plate tectonics system and the event occurring due to plate tectonics can be predicted.
Explanation:
Xenopus laevis is allotetraploid: it has 2 sets of homologous chromosomes originally from one species and 2 sets of homologous chromosomes originally from another species, making a total of 4 sets of chromosomes. During meiosis, every chromosome has another homologous one with which it can pair, producing viable gametes that have the complete genetic information of the species.
Mules, however, are allodiploid: they have one set of chromosomes from a donkey and another set from a horse, making a total of 2 sets of chromosmes. But those two sets are not homologous, so during meiosis the chromosomes can't pair and the gametes will have errors that make them inviable, making mules sterile
The answer to your question is A., as the random movement is a movement
Water is a polar molecule because its opposite ends have opposite electric charges.
Having the occasional alcoholic drink is unlikely to affect your fertility. But heavy drinking and smoking can reduce sperm quality, lower testosterone production, and make it harder to achieve an erection. It can also lead to liver damage, which affects both your general and reproductive health