Q: What makes toenails and fingernails hard? Choices: - guanine - cellulose - taurine - keratin A:
keratin

Q: What prohibits knocking out genes? Choices: - genetic considerdations - professional considerations - moral considerdations - ethical considerdations A:
ethical considerdations

Q: Which proteins bind to the surfaces of microorganisms and are particularly attracted to pathogens that are already tagged by the adaptive immune system? Choices: - attractive proteins - mobilize proteins - whereby proteins - complement proteins A:
complement proteins