How does leaving the stems and roots of a crop in the soil after harvest protect an ecosystem?

Which statement about inheritance is true? o girls get most of their traits from their moms, boys get most of their traits from their dads. o male offspring will always have an x-linked genetic disease if the mom is a carrier o fathers always determine the gender of the offspring in humans. o males never have y chromosomes.

Which is an advantage of having memory cells when a pathogen is encountered for a second time. a) the memory cells are what proliferate into clones of cells in response to the binding of an antigen. b) memory cells are vital to the primary immune response in that they immediately recognize pathogens even at the first encounter. c) memory cells are essentially effector cells that are short lived and attack antigens even without having a receptor specific to that antigen. d) it ensures that more lymphocytes with a receptor specific to a particular antigen will be present than in a host that had never encountered that pathogen.

In a cross between individuals of a species of tropical fish, all of the male offspring have long tail fins, and none of the females possess the trait. mating two of the f1 fish fails to produce females with the trait. explain the inheritance pattern of the trait.