Sometimes a trait seems to disappear in a family and then reappear in later generations. if neither parent has the trait, but some of the offspring do, what would you conclude about the inheritance of the trait?

That it is either recessive and both parents are heterogeneous, or that it is sex linked and the mother is a carrier for the trait.

An autotrophic protist - they can perform photosynthesis and mainly consist of unicellular algae. they can be divided into number of systematic group according to the shape of their cell and the type of photosynthetic pigments they use.