Regarding Koch’s postulates:
I. The microorganism must be present in every case of the disease
II. The microorganism must be cultured in pure form
III. The microorganism must cause disease when introduced into a healthy host

#Question id: 4654

#Zoology

Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from very similar embryonic tissues. How do biologists interpret these similarities?

#Question id: 4655

#Zoology

Over evolutionary time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses?

#Question id: 4656

#Zoology

Logically, which of these should cast the most doubt on the relationships depicted by an evolutionary tree?

#Question id: 4657

#Zoology

 Which of the following statements most detracts from the claim that the human appendix is a completely vestigial organ?

#Question id: 4658

#Zoology

Members of two different species possess a similar-looking structure that they use in a similar fashion to perform the same function. Which information would best help distinguish between an explanation based on homology versus one based on convergent evolution?

#Question id: 4698

#Zoology

It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that