Two brown heterozygous horses mate, calculate the genotypic frequency

What is thought to have caused the mass extinction at the end of the cretaceous period?

Which best describes the digestive system of arthropods? a incomplete, two openings b complete, one opening c two-way, one opening d one-way, two openings

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