I'd go with this one: b.) Meiosis I separates tetrads, and meiosis II separates sister chromatids. As it is correctly describes the difference between meiosis I and meiosis II.
I don’t really understand this question can you go more into detail
They all under the kingdom animalia. The others are plantae, fungi and Protoctista.
Through crossing over during meiosis. In eukaryotic cells (us), there are these things called Histone proteins. TONS of these wrap around and form what eventually will be a chromosome in the nucleus of the cell. These chromosomes contain genes which contain genetic information in the form of DNA. If a trait is sex linked it will pass through to the offspring by meiosis, specifically during crossing over when homologous chromosomes exchange genetic information.