How might Devonian osteolepiforms have facilitated the transition of animals to land?
What will be an ideal response?
ANSWER: Most osteolepiforms had strong, stout fins that enabled them to crawl on the muddy bottom
of shallow pools, and their vertebral column included crescent-shaped bones that provided
good support. They also had nostrils leading to sensory pits that housed olfactory receptors.
Finally, they probably had lungs to augment gill respiration in the swampy, oxygen-poor
water where they lived.
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What organisms are most often displaced by the invasive species of zebra mussels?
a. Chinook salmon b. coral reefs c. other mussel species d. snail darters
Adam was certain that he had Native American ancestors, based on tales that his grandfather told of the family history. He is disappointed when he takes a genetic ancestry test by sending a saliva sample to a testing company, because it does not confirm what he believed to be true. Adam may actually indeed have Native American ancestors because
A) DNA ancestry tests must be performed on blood to be accurate. B) DNA ancestry tests only work on females, because only they have mtDNA. C) the DNA sequences identified in ancestry tests do not reflect input from all lineages. D) the testing labs do not test for Native American Y chromosome sequences.
An Rh-negative mother will need a special treatment if she gives birth to an Rh-positive baby. The treatment involves the destruction of any stray blood cells from the baby that pass into the mother's bloodstream. Why is this necessary?
A) The mother's immune system will attack the Rh-positive cells and produce antibodies that will attack a fetus in a subsequent pregnancy. B) The mother's immune system will attack her own blood cells and the cells in the fetus of a subsequent pregnancy. C) Without this treatment, the mother's immune system will attack only her own blood cells. D) Without this treatment, antibodies will be formed in breast milk, which could harm the baby.
Which of the following are adaptations for terrestrial life seen in plants?
a. Sporopollenin and an embryo protected and nourished by the parent plant b. Chlorophylls a and b c. Cell walls of cellulose and lignin d. Vascular tissue e. Cuticle and stomata