Pedigrees are used to geneticists understand how traits are inherited between generations. the romanovs, a russian royal family, had a history of hemophilia, a sex-linked disorder that is determined by a recessive allele on the x chromosome. mc014-1.jpg what is the best evidence to prove that irene was heterozygous for hemophilia? alice carried the recessive allele. alexandra carried the recessive allele. frederick carried the recessive allele. waldemar carried the recessive allele.

20. in humans, freckles are dominant to no freckles. trey has no freckles and his wife anna grace has freckles, but her dad doesn't. they want to know what percentage of their kids would look like trey. show a punnett square to support your answer.

Which of the following statements is correct in hour our immune system responds to a potential pathogen? a. the adapted immune system will call on the innate immune system to destroy the pathogen. b. b cells will start reading the antigen code immediately and call t cells to assist in destroying the pathogen. c. the skin will be the first line of defense, and then the many phagocytes in the bloodstream will attempt to consume the possible pathogen. d. the t-cells in the adapted immune systems are the first to recognize the pathogen vaccines are weakened forms of disease causing microorganisms, which are given to patients to prevent disease. after the vaccine is administered, the immune system responds by creating a(n) to recognize the a. antigen, antibody b. antibody, antigen c. antibody, antibiotic d. antibiotic, antibody

The pacific plate is an oceanic tectonic plate. how did a hot and the pacific plate interact to form the hawaiian islands?