What technological advancement was necessary before scientist could begin to observe cells?

Ascientist discovers a new body between the orbit of neptune and the kuiper belt. the object is round and travels in an orbit around neptune with other space objects. the scientist claims that she has found a new dwarf planet. where is the scientist’s error?

Beth’s hygrometer is reading a temperature of 30 c and a relative humidity of 65%. the humidity in the air is?

In meiosis ii during anaphase ii which structures separated homologous chromosomes or sister chromatids