Two fossils of the same species are found in both Africa and South America. What does this indicate?

Monotremes, like the duck-billed platypus, are egg-laying mammals (oviparous), covered in hair, have mammary and skin glands, three ear ossicles, are diphyodont (their permanent teeth replace their “baby” teeth), and possess dentary-squamosal jaw articulation (the jaw bone hinges with the squamosal bone of the skull). Marsupials, such as kangaroos and koalas, are pouched mammals that have a vertical tympanic membrane in addition to being covered in hair, have mammary and skin glands, three ear ossicles, are diphyodont, and possess dentary-squamosal jaw articulation. Eutherians are the placental mammals that most people easily recognize as mammals. They are covered in hair, have mammary and skin glands, three ear ossicles, are diphyodont, possess dentary-squamosal jaw articulation, and have a vertical tympanic membrane. What traits are shared derived traits for monotremes, marsupials, and eutherians?

For which of the following would a mountain range most likely represent a geographic barrier that would block gene flow?

The Cambrian explosion occurred primarily in the oceans. Which of the following were the first challenges that had to be overcome during the mass colonization of dry land in the Ordovician period?

The mass extinction at the end of the Cretaceous period about 65 mya is believed to have been caused by a massive comet or asteroid smashing into what is now known as the Yucatan peninsula in the Gulf of Mexico. The debris arising from this impact would have blocked the Sun’s rays from reaching the Earth. How would this cause a mass extinction?

Equus (horses) have a single toe on their hoof, while Hyracotherium (the ancestor to horses) had four toes. Which of the following evidence would support this conclusion?

EXTRA CREDIT #3 (1 pt) Match the type of neurons found in the associated tissues

Which of the following is responsible for the buffer system in the blood?

Which of the following is responsible for the buffer system in the blood?

Which part of the brain is labeled A in the picture above?