The order cetacea includes modern-day whales, dolphins, and porpoises. these marine mammals share common characteristics that have led scientists to make a conclusion about their evolutionary history. cetaceans:
lack gills and must breathe air
give birth to live young rather than lay eggs
have fin bones that are similarly shaped to limb bones
have spines that flex up and down rather than side to side
the characteristics of cetaceans provide evidence that
a.
they evolved from land mammals.
b.
the theory of evolution is incorrect.
c.
they evolved from air-breathing fish.
d.
the bodies of their ancestors never changed.

Which is it a characteristic of the animal kingdom? a. they include both vertebrates and invertebrates b. their skin is covered with hair or fur c. they are heterotrophs d. they are eukaryotic

Look at the images of different rocks. which rocks have a fine-grained texture? check all that apply. 1 2 3 4 5

Two students are working together on an experiment that measures the effect of different liquid fertilizers on the thickness of plants’ stems. which is most likely to result in the greatest amount of error in their scientific experiment? a.one student measures the plant stem widths by using calipers. the other student measures the widths of the same plant stems again by using a different pair of calipers. b.one student measures the plant stem widths by using calipers. the other student types the measurements as they are taken into a computer spreadsheet. c.one student weighs liquids for the experiment by using a calibrated scale. the other student weighs liquids for the experiment by using a different calibrated scale.