Which process is a source of variation for organisms

Asap i will reward you brainliest for best which sentence about protists is accurate? all protists are unicellular and microscopic in nature. they have organelles, so protists are eukaryotic in nature. all protists make their own energy through photosynthesis.

Explain the source of radioactivity in uranium in earth’s crust by which it produces nuclear radiation

Ineed to get this test done which of the following statements is correct in hour our immune system responds to a potential pathogen? a.) the skin will be the first line of defense, and then the many phagocytes in the bloodstream will attempt to consume the possible pathogen. b.) b cells will start reading the antigen code immediately and call t cells to assist in destroying the pathogen. c.) the adapted immune system will call on the innate immune system to destroy the pathogen. d.) the t-cells in the adapted immune systems are the first to recognize the pathogen