Contrast the following terms: monophyletic, paraphyletic, and polyphyletic. Provide one example for each. What will be an ideal response?
A monophyletic group includes an ancestral species and all its descendants. It is defined by
shared derived characteristics. For example, all mammals are believed to be descended from
a common ancestor that had mammary glands, three small bones in middle ear, and a
muscular diaphragm.
A paraphyletic group contains a common ancestor and some, but not all, of its descendents.
The class Reptilia is paraphyletic because it does not include all descendants of the most
recent common ancestor.
A polyphyletic group consists of several evolutionary lines that do not share a most recent
common ancestor. The domain Bacteria and the Domain Eukarya constitute a polyphyletic
group because they do not share the most recent common ancestor.
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Instinctive behaviors that are performed in exactly the same way every time they are triggered are
defined as ____.
a. sign stimuli b. fixed action patterns c. releasers d. habitual behaviors e. conditioned behaviors
How is it that the cells in different body tissues are able to perform different functions?
A) The cells exhibit different patterns of gene expression. B) Different chromosomes have been inactivated in different cells. C) The cells contain different genes. D) The mutations that have accumulated in the cells of the different tissues control functions.
The site of formation of pollen grains is in the
a) receptacle. b) stamen. c) sepal. d) carpel. e) petal.
Which of the following joints is a fibrous joint?
A. intervertebral disks B. elbow C. knee D. ribs and sternum E. sutures between cranial bones