What adaptations have evolved in birds to assist them in flight?
What will be an ideal response?
Answers should address the following: Birds have modified their forelimb structure to form wings and have insulating feathers that extend the wing surface. They have lightened their skeletons, evolving porous bone and replacing their teeth with light, horny beaks. They have increased their activity level and ability to move powerfully by evolving endothermy, lungs with air sacs that are particularly efficient at acquiring oxygen, and a four-chambered heart that is efficient at delivering oxygen.
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Destruction of the motor areas in the right cerebral cortex results in the loss of
a. sensation on the right side of the body. b. sensation on the left side of the body. c. voluntary movement on the left side of the body. d. voluntary movement on the right side of the body. e. involuntary control of the right side of the body.
The number of differences between human cytochrome c and cytochrome c of some other organisms is as follows: rhesus monkey - 1 difference; pigeon - 12 differences; and fruit fly - 24 differences. The order in which these species are most similar to humans is
A. rhesus monkey, fruit fly, pigeon. B. rhesus monkey, pigeon, fruit fly. C. pigeon, fruit fly, rhesus monkey. D. fruit fly, pigeon, rhesus monkey. E. pigeon, rhesus monkey, fruit fly.
Although carbon dioxide contains carbon, it is not considered an "organic" compound because ____
a. it is not found in the earth's crust b. it is not present in living cells c. the carbon atom is not bonded to at least one hydrogen atom d. the carbons are not in chains or rings e. it is too small
How does the first nucleotide at the 5? end of a new mRNA chain differ from the other nucleotides in the chain?
a. The first nucleotide is always a uracil. b. The first nucleotide is always a cytosine. c. The first nucleotide retains its triphosphate group, while the others do not. d. The first nucleotide does not retain its triphosphate group, while the others in the chain do. e. The first nucleotide is always a modified cytosine.