Animal body plans can evolve, because changes in genes that regulate development will alter body form. However, some factors limit the changes that can occur. Describe these factors
What will be an ideal response?
First, physical constraints limit body form. Large body size cannot evolve in an animal that does not have circulatory and respiratory mechanisms sufficient to service cells far from the body surface.
Second, an existing body framework imposes architectural constraints. For example, the ancestors of all modern land vertebrates had a body plan with four limbs. The evolution of wings in birds and bats occurred through modification of existing forelimbs, not by sprouting new limbs.
Finally, there are phylogenetic constraints on body plans. These constraints are imposed by interactions among genes that regulate development in a lineage. As master genes evolved together, their interactions became more enmeshed in pathways that unravel if one component is not working; their interactions determine the basic body form.
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Which of the following would help a virus avoid triggering an effective adaptive immune response?
I) having frequent mutations in genes for surface proteins II) building the viral shell from host proteins III) producing proteins very similar to those of other viruses IV) infecting and killing helper T cells A) only I and III B) only I, II, and IV C) only II and IV D) only I, II, and III E) only II, III, and IV
Some cells are very large, seemingly in defiance of maintaining a large surface area to volume ratio. What are some
strategies or adaptations that these cells may use in order to maintain a reasonable surface area to volume ratio? What will be an ideal response?
In the simple linear regression, the intercept will equal the sample average of the outcome (Y) variable if which of the following is true?
A. sCov(X, Y) < 0
B. sCov(X, Y) > 0
C. 
= 0
D. sVar(X) > 0
In making active predictions based on sample data it requires the use of what sort of reasoning?
A. Deductive reasoning only B. Always deductive reasoning and only inductive reasoning when determining if an estimator is unbiased C. Inductive reasoning only D. None of the answers is correct.